(a), is the art of preparing, preserving, and compounding substances, for the purposes of medicine. This art has been commonly divided into two branches, Galenical and Chemical pharmacy. But for this division there is no foundation in nature; and accordingly processes in one pharmacopeia referred to the head of Chemical, are in another referred to the head of Galenical. There can be no doubt, that even the most simple pharmaceutical preparations are to a certain extent chemical. Hence this division, founded on prejudice, and supported merely by a veneration for antiquity, is now banished from almost every modern pharmacopeia.

Pharmacy has also been divided into Theoretical and Practical; the first, consisting not merely of speculative opinions, but of a knowledge of facts and principles, tending to explain the rationale of processes; the latter, comprehending the mere manual labour employed in processes.

The former of these may therefore be justly styled Scientific Pharmacy. And there can be no doubt that an acquaintance with it is essentially necessary to the physician as well as the apothecary: for without it he must often err in the forms of preparations and compositions which he employs; and must be often deceived in the effects resulting from compositions, when he infers their properties from the known powers of the ingredients in their separate state.

The theory of pharmacy therefore is the same with that of chemistry; as are also the operations, which remain to be discussed here only in so far as they are made subservient to the medicinal art, distinct from that which is purely chemical. The objects of pharmacy, however, are much more limited than those of chemistry; the latter comprehending, in the utmost latitude of the word, almost every substance in nature; while pharmacy regards only such bodies in the vegetable, animal, and mineral kingdoms, as, by their effects on the human frame, tend to preserve health, or to restore it when lost.

PART I. ELEMENTS OF PHARMACY.

CHAP. I. A general View of the Properties and Relations of Medicinal Substances.

SECT. I. VEGETABLES.

Vegetables are organized bodies, furnished with a variety of vessels for reception, transmission, and perspiration of different fluids. Analogous to animals, they are produced from seeds and eggs, and are endowed with functions, by which the aliment they imbibe is changed into new forms, into solids and fluids, peculiar to particular plants, and to different parts of the same plant.

The analogy between the vegetable and animal kingdoms will appear still more striking, when we consider that the former exhibit, though in a less degree, all the phenomena of fertility and motion.

The pabulum of vegetables, like that of most animals, is of a mixed nature; and is composed of the necessary union of water, heat, and light, and less necessarily of air and earth: the office of these two last elements seems to be that of filters, or vehicles for conveying the other principles in proper form.

From varieties in the state and proportion of these several agents, a very multiplied diversity takes place in the external form, quantity, and quality, of one and the same vegetable: hence the difference of plants from the soil, climate, seasons, and other similar circumstances. The influence of heat and light, or what is probably the same thing, the absorption of the inflammable principle, is perhaps the most important article in the aliment of vegetables. This principle, whether derived from the solar rays, from putrid matters employed in manure, or from the putrefaction of the wild growth, assisted by calcareous earths and other septic, is found at all times to modify, in a peculiar manner, the form, the quantity, and even the sensible and inherent properties, of vegetables. It is of importance however to remark, that the soundness and specific principles of vegetables are not invariably the more complete in proportion to the vigour of their growth; high health, which is always a dangerous state in the constitution of animals, is often the means

(a) For this article we are indebted to the liberality of Mr Creech bookseller in Edinburgh, who, with his well known zeal for the cultivation of science, and, regardless of the advantage to be expected from his copy-right, has permitted us to insert into this work the third and much improved edition of the Edinburgh New Dispensatory. means of perverting or destroying the economy of vegetable life. Thus the finer aromatics, which naturally inhabit the dry and sandy soils, when transplanted into a moist and rich one, or, in other words, when placed in mould abounding with the fomites of inflammable principle, grow with rapidity and vigour, and have their bulk considerably increased; but lose very much of their fragrance, as if their active principles were exhausted by the luxuriance of their growth.

Plants are also found to differ considerably in the different periods of their growth. Thus, some herbs in their infancy abound most with odoriferous matter; others again yield little or none till they have attained to a more advanced age. Many fruits, in their immature state, contain an aulic acid juice, which by maturation is changed into a sweet one; others, as the orange, are first warm and aromatic, and afterwards by degrees become filled with a strong acid. The common grain, and sundry other seeds, when beginning to vegetate, are in taste remarkably sweet; yet the kernels of certain fruits prove, at the same period, extremely acid. The roots of some of our indigenous plants, whose juice is, during the summer, thin and watery, if wounded early in the spring, yield rich balsamic juices, which, exposed to a gentle warmth, soon concrete into solid gummy-reins, superior to many of those brought from abroad. In open exposures, dry soils, and fair warm seasons, aromatic plants become stronger and more fragrant, while those of an opposite nature become weaker. To these particulars, therefore, due regard ought to be had in collecting plants for medicinal uses.

It may be proper to observe also, that the different parts of one plant are often very different in quality from each other. Thus the bitter herb wormwood rises from an aromatic root; and the narcotic poppy-head includes seeds which have no narcotic power. These differences, though very obvious in the common culinary plants, do not seem to have been sufficiently observed or attended to, in those plants that have been admitted as articles of the materia medica.

Without any obvious dependence on the circumstances above-mentioned, vegetables are, like animals, also obnoxious to diseases and death; which, whether occasioned by intense cold, by insects, lightning, or other causes, always maintain a striking analogy to the affections of animals. The principal difference between animals and vegetables is, that the several parts of vegetables do not constitute such a mutually depending system as those of the more perfect animals: Hence it is, that a very considerable part of a plant may be diseased or dead, while the rest enjoys perfect good life and health. Though the physiology of vegetables is hitherto insufficient for forming any complete doctrines of the causes and cure of their several diseases; yet, in many cases, it might be useful to attend to the formation of a pathology of the vegetable kingdom; in the state even of our present knowledge, it is of importance in the study of pharmacy to be aware that such diseases really exist, and are capable of changing or destroying the active principles of many of our most valuable herbs. In the plants more evidently sensitive, the diseases exhibit a very close analogy to many of those of animals; several of the remote causes are such as are known to obstruct perspiration, to induce general debility, or otherwise disorder the animal economy. The diseases also are evidently marked by a diminution of their sensitive and moving principle; and perhaps, in consequence of this diminution, their solids, their sap, and other fluids, shrivel and decay, and the whole plant assumes new forms, and is impregnated with inert, or fraught with noxious principles. Analogous also to animals, the plant, when deprived of the living principle, runs into all those changes common to what is called inanimate matter. We shall now proceed to examine the changes to which vegetables are subject.

I. Productions from Vegetables by Fermentation.

Fermentation is a spontaneous motion excited in fermenting dead vegetables and animals, which is peculiar to those organic substances in consequence of the principle of vegetable or animal life. See Fermentation.

The circumstances favouring fermentation are in general, a certain degree of fluidity, a certain degree of heat, and the contact of the air.

There are, however, several substances, of themselves not susceptible of fermentation, which nevertheless may be brought into that state by the admixture of those that are; as by adding to them, along with a proper quantity of water, a portion of the yeast or head thrown up to the surface of fermenting liquors. Without this expedient many vegetables would run immediately into the acetous, and some of them into the putrefactive, fermentations. It is also found, that though acetous and putrefactive ferments are unable to stop the vinous fermentation, they are however capable of assimilating the liquor to their own nature in a more perfect form: and hence it is, that in the manufactures of wine, rum, and vinegar, it is found useful to keep the vessels well seasoned with the liquor intended to be prepared. Three different kinds of stages of fermentation have been generally distinguished by chemists. The vinous, which furnishes alcohol, or what is commonly called spirit; the acetous, which affords vinegar; and the putrefactive, which yields volatile alkali. Being generally constant in succession to each other, the whole process will be best understood by considering each of them apart. All vegetable substances are not capable of the vinous fermentation: the conditions necessary to its production are, a saccharo-mucilaginous matter; a fluidity somewhat viscous, the proper degree of which is best learned from experience; a heat from 40 to 96 of Fahrenheit's thermometer; a considerable mass of matter; and the access of the external air.

The phenomena exhibited in the vinous fermentation are, a brisk tumultuary motion, the liquor loses its transparency and homogeneous appearance, its bulk and heat are considerably increased, the solid parts are buoyed up to the top, and a great quantity of a permanently elastic fluid is disengaged. This fluid or gas being heavier than atmospheric air, floats in separate masses near the surface of the liquor; and is easily distinguishable from common air by extinguishing flame and animal life, precipitating lime from limewater, crystallising and rendering mild the caustic caustic alkali; is the gas sylvestre of Helmont, and the fixed air, aerial acid, or carbonic acid of modern chemists. After some time the tumultuary motion in the liquor is suddenly checked, perhaps from the generation of the alcohol; a fine ley is also precipitated; and the floating matter, if not purposely prevented, subsides to the bottom of the vessel. In the wines produced from the grape, a large quantity of saline concrete is incrustated on the sides and bottom of the casks; and this is commonly known by the name of tartar, the properties of which we shall afterwards examine. At the termination of these phenomena, the vegetable matter has assumed new properties; and from being a mild, sweet, or gently acridulous infusion, is now become the brisk, pungent, and exhilarating liquor, called wine or vinous liquor.

Fermented or vinous liquors are prepared from a great variety of substances: the saccharine substances, or those rendered so by a beginning vegetation, are in general fittest for the purpose; a multitude of collateral circumstances are also necessary for the proper management of the process; and in vinous liquors great diversities are observable. These differences are not only observable in wines produced from different substances, but also in those prepared from one and the same vegetable. These diversities may be referred to the different conditions of the substance to be fermented, to the states of fluidity and heat, and to the degree of fermentation to which the subject has been carried. This last is principally modified by the preceding causes, and not unfrequently by very minute and apparently trifling circumstances in the conduct of the operator. Hence the numerous varieties in the vinous liquors produced from the grape, which have been more peculiarly denominated wines. It is an important part of pharmacy to inquire into these differences with care and attention.

The diversity in vinous liquors is still more obvious in those produced from different vegetables. Many of the native qualities of the substances, as colour, taste, flavour, &c. often remain in the wine; not being totally subdued by that degree of fermentation necessary for rendering the liquor vinous. Hence the remarkable difference of wines produced from the grape and the grassy seeds: the wine produced from these last has been more strictly called beer; and is well known to differ from wines produced from apples, pears, apricots, or any other fruit.

1. Of the Product of the Vinous Fermentation.

The product of all these fermented vegetables is, as we have just now mentioned, the pungent and intoxicating liquor called wine. It is proper, however, in pharmacy, to inquire into the different principles which enter its composition. As the wine furnished by grapes is the most valuable and generally known, we shall take it as an example: Grape-wine, then, is composed of a large quantity of water, of alcohol, of tartar, and of a colouring matter. It is proper, however, that we should lay down the proofs of such a combination in wine, and explain the methods by which it may be decomposed and separated into the constituent parts above-mentioned.

For this purpose, recourse is generally had to the assistance of the fire. The liquor is put into an alembic; and as soon as it boils, a white milky fluid, of a pungent smell and taste, distils into the recipient. This fluid is called aquavitæ, or, in common language, spirit: it is compounded of water and certain matters capable of suspension in water, of alcohol, and of a small proportion of oil; which last communicates to it a milky colour: the yellow colour, afterwards assumed, is partly owing to the same oil, and partly to a solution of the extractive matter of the wooden casks in which the aquavitæ has been kept. This aquavitæ, like wine, always partakes more or less of the flavour of the vegetable from whence it has been prepared; but by farther distillation, and other processes, it is freed of its water, and of the native principles of the vegetable matter which the watery parts had kept in solution; when thus prepared, it is a pure alcohol or inflammable spirit, which is always the same from whatever vegetable the wine was produced.

After all the aquavitæ has been drawn off, the residuum now ceases to be wine; it is of a chocolate colour, of an acid and astringent taste; it has now assumed a heterogeneous appearance, and a great quantity of saline crystals is observed in the liquor; these crystals are the tartar. By the above processes, then, we have fully decomposed wine: but it is to be observed, that by this analysis we have not separated the different parts of wine in their original and entire state; nor are we hitherto acquainted with any method of regenerating the wine by recombining the aquavitæ with the residuum: some product of the fermentation is therefore changed or destroyed; and this product is probably some peculiar modification of fixed air or aerial acid. The residuum, when evaporated, assumes the form and consistence of an extract; the colouring part may be abstracted by rectified spirit of wine, but is not separable from it by the addition of water; it seems therefore to be of a gummi-resinous nature, and extracted from the grape by means of the alcohol generated during the fermentation.

From this analysis, then, it is obvious, that wine water, composed of water, colouring matter, alcohol, and something that is changed or lost. We shall refer to the particular examination of alcohol and tartar at the proper places assigned them in this work; and we hope that from this general survey of the subject, the properties of wine, as a solvent of several medicinal substances to be afterwards examined, will be much more readily understood. Before we go farther, it is proper to add, that the ley precipitated from wine during fermentation, is a compound of stones, pieces of grape, tartar, and vitriolated tartar: the two first are inert bodies; the two last we shall particularly examine in their proper order. We are now prepared to consider the nature and product of the next kind or stage of fermentation, viz. the

2. Acetous Fermentation.

To understand the process of the acetous fermentation, we must leave for the present our analysis of the product of the vinous fermentation, and return to the wine in its most perfect and entire state. It is proper to observe, that though, after the liquor has become vinous, a partial cessation of the more obvious phenomena phenomena takes place, yet the wine still suffers a slow and imperceptible degree of fermentation. We are not then to consider the liquor as being in a quiescent state, but as constantly approaching to the next stage, viz. the acetous fermentation, which we are now to consider. This kind of insensible fermentation, or what we may call the intermediate change, seems to be necessary to the perfection of the wine. Its degree, however, is to be regulated under certain limitations: when too much checked, as by cold, thunder, or such like causes, the wine becomes vapid; when too much encouraged by heat, contact of air, &c. it approaches too far to the acetous change: but in order that the vinous shall proceed fully to the acetous fermentation, several circumstances are required; and these are in general the same that were before necessary to the vinous stage. These conditions are, a temperate degree of heat, a quantity of unfermented mustage, an acid matter, such as tartar, and the free access of external air. When thus situated, the liquor soon passes into the acetous fermentation: but during this stage the phenomena are not so remarkable as in the vinous; the motion of air is now less considerable, a gross unctuous matter separates to the bottom, the liquor loses its vinous taste and flavour, becomes sour, and on distillation affords no inflammable spirit. It is now the acetous acid or vinegar; and when separated by distillation from the unctuous ley, may be preserved a considerable length of time without undergoing the putrid change: to this last, however, it always approaches in the same manner as the vinous constantly verges to the acetous fermentation; and this will much more readily happen if the acid be allowed to remain with the unctuous feculent matter above-mentioned. When thus situated, the vinegar quickly loses its transparency, assumes a blackish colour, loses its sourness and agreeable odour, has an offensive taste and smell, and, when distilled at a certain period of the process, yields volatile alkali.

The liquor is now arrived to the last stage, viz.

3. The Putrefactive Fermentation.

From the preceding phenomena, it is obvious, that the same substance which is capable of the vinous and acetous, is also capable of the putrefactive fermentation. It is perhaps impossible to induce the first without a mixture of the second; or the second without a mixture of the third. Hence every wine is a little acid; and there are few vinegars without some disposition towards putrefaction, or without volatile alkali, neutralized by the acid which predominates. Notwithstanding this seeming continuation of one and the same process, the putrefaction of vegetables has its particular phenomena. The vegetable matter, if in a fluid state, becomes turbid, and deposits a large quantity of feculent matter; a considerable number of air-bubbles are raised to the top; but their motion is not so brisk in the putrefactive as in the vinous, or even the acetous fermentation: neither the bulk nor heat of the liquor seems to be increased; but an acrid pungent vapour is perceived by the smell, and which, by chemical trials, is found to be the volatile alkali; by degrees this pungent odour is changed into one less pungent, but much more nauseous. If the same train of phenomena have taken place in a veget-

table consisting of parts somewhat solid, its cohesion is broke down into a soft pulpy mass; this mass, on drying, entirely loses its odour, leaving a black cherry-like residuum, containing nothing but earthy and saline substances.

It is proper to observe, that though the circumstances favouring the putrefactive are the same with those requisite to the vinous and acetous fermentations, yet these several conditions are not so indispensible to the former as to the two latter stages. All vegetables have more or less tendency to putrefaction, and a great number of them are capable of the acetous fermentation; but the proportion of those capable of the vinous is not considerable; and these last will run into the putrid in circumstances in which they cannot undergo the vinous or even the acetous fermentations. Thus flour made into a soft paste will become foul; but it must be perfectly dissolved in water to make it fit for the vinous stage; whereas mere dampness is sufficient to make it pass to the putrid fermentation: besides the condition of fluidity, a less degree of heat, and a more limited access of air, are sufficient for producing the putrefactive fermentation.

It is therefore probable, that all vegetables, in whatever state they may be, are liable to a kind of putrefaction: in some the change is slow and gradual, but never fails at length to break down the texture and cohesion of the most solid.

We formerly observed, that the vapours separated during the vinous fermentation were fixed air or aerial acid; and it is indeed true, that in the incipient state of this fermentation a quantity of gas is still evolved, and along with it a quantity of alkaline air; in the advanced state, however, we find these vapours of a different nature; they now tarnish silver, and render combinations of lead with the vegetable acids black. When produced in large quantity, and much confined, as happens in stacks of hay put up wet, they burst into actual flame, consuming the hay to ashes: on other occasions, the escape of these vapours discovers itself by an emission of light, as in the luminous appearance of rotten wood when placed in the dark. From the above phenomena it is evident, that these vapours abound with the principle of inflammability; and their odour probably depends on this principle loosely combined with the water, or some other parts of the volatilised matter. This gas Hydrogen is therefore different from that separated during the vinous fermentation; it is the phlogisticated, and sometimes the inflammable air of Dr Priestley, or the hydrogen of Lavoisier. See table of chemical nomenclature, &c. Chemistry, page 598.

We have thus, for the sake of clearness, and in order to comprehend the whole of the subject, traced the phenomena of fermentation through its different stages: it is proper, however, to observe, that though every vegetable that has suffered the vinous will proceed to the acetous and putrefactive fermentations, yet the second stage is not necessarily preceded by the first, nor the third by the second; or in other words, the acetous fermentation is not necessarily confined to those substances which have undergone the vinous, nor the putrefactive to those which have undergone the acetous fermentation. Thus it is, that gums dissolved in water pass to the avetous without undergoing the vinous fermentation; and glutinous matter seems to run into putrefaction without showing any previous aceseence; and farther, these changes frequently happen although the matter be under those conditions which are favourable to the preceding stages.

From the foregoing sketch, the importance of this subject in the study of Pharmacy will be obvious at first sight: it cannot, however, afford us any useful information on the native principles of vegetables; but it presents to us new products, the importance of which is well known in chemistry, in medicine, and in arts. The necessity of being well acquainted with the several facts (for of theory we know none satisfactory), will appear in the pharmaceutical history and preparation of many of our most valuable drugs. We are next to consider a set of no less complicated operations, viz.

II. Productions from vegetables by Fire.

In order to analyse, or rather to decompose, vegetables by the naked fire, any given quantity of dry vegetable matter is put into a retort of glass or earth. Having filled the vessel about one half or two thirds, we place it in a reverberatory furnace, adapting it to a proper receiver. To collect the elastic fluids, which, if confined, would burst the vessels (and which, too, it is proper to preserve, as being real products of the analysis), we use a perforated receiver with a crooked tube; the extremity of which is received into a vessel full of water, or of mercury, and invested in a basin containing the same fluid: by this contrivance, the liquid matters are collected in the receiver, and the aeriform fluids pass into the inverted vessel. If the vegetable is capable of yielding any saline matter in a concrete state, we interpose between the retort and the receiver another vessel, upon whose sides the salt sublimes. These things being properly adjusted, we apply at first a gentle heat, and increase it gradually, that we may observe the different products in proper order. At first an insipid watery liquor passes over, which is chiefly composed of the water of vegetation; on the heat being a little farther increased, this watery liquor, or phlegm, becomes charged with an oily matter, having the odour of the vegetable, if it possessed any in its entire state; along with this oil we also obtain an acid resembling vinegar, and which communicates to the oil somewhat of a saponaceous nature; on the heat being carried still farther, we procure more acid, with an oil of a dark colour, and the colour gradually deepens as the distillation advances. The oil now ceases to retain the peculiar odour of the vegetable; and being scorched by the heat, sends forth a strong disagreeable smell like tar: it is then called empyreumatic oil. About this time also some elastic vapours rush into the inverted vessel; these generally consist of inflammable or fixed airs, and very often of a mixture of both; the volatile salt now also sublimes, if the vegetable was of a nature to furnish it. By the time the matter in the retort has acquired a dull red heat, nothing further will arise: we then stop; and allowing the vessel to cool, we find a mass of charcoal, retaining more or less the form and appearance of the vegetable before its decomposition.

We have thus described, in the order of their succession, the several products obtained from the generality of vegetables when analysed in close vessels and in a naked fire.

It is, however, to be understood, that the proportion of these principles turns out very various; the more succulent yield more water, and the more solid afford a greater quantity of the other principles. Independently also of this difference, the nature of the productions themselves are found to differ in different vegetables: thus in the cruciform plants, and in the emulfive and farinaceous seeds, the saline matter which comes over with the water and oil is found to be alkaline; sometimes it is ammoniacal, from the combination of the acid with the volatile alkali passing over at the end of the process; it is also probable, that the acids of vegetables are not all of the same nature, though they exhibit the same external marks. When volatile alkali is obtained, it is always found in the mild effervescing state; it is procured, however, from a few vegetables only; it is seldom in a concrete form, being generally dissolved in the phlegm; and as it ordinarily makes its appearance about the end of the process, it is probable that its formation is owing to some peculiar combination of the oil and fixed alkali. The plants containing much oily combustible matter seem to be those which more peculiarly yield inflammable air, while the mucilages appear to be as peculiarly fitted for affording the fixed air or aerial acid. The chemical properties of charcoal seem to be always the same from whatever vegetable it has been produced: on a minute examination (which, however, is not the business of pharmacy), it is found to consist of fixed air, the principle of inflammability, a small quantity of earth, saline matter, and a little water. The whole of the analysis then amounts to air, water, earth, and the principle of inflammability; for by repeated distillations the oil is resolved into water, the principle of inflammability, and a little earth; the saline matter also is a product arising from a combination of the earthy matter with water or the principle of inflammability, in some shape or other, or perhaps with both. That these combinations take place, has at least been the opinion of the chemists.

We formerly said that charcoal was partly composed of saline matter; it therefore remains that we should next decompose the charcoal, in order to obtain or separate the articles next to be mentioned.

The fixed Salts of Vegetables.

When vegetable charcoal has been burnt, there remains a quantity of ashes or cinders of a blackish grey or white colour: these, when boiled or infused in water, communicate to it a pungent saline taste; the salt thus held in solution may, by evaporation, be reduced to a concrete state: this saline matter, however, is generally found to be mixed with ferruginous earthy and other impurities, and likewise with a number of neutral salts of different kinds. In this mixed condition it is the

Potash used in Commerce.

This salt, or rather compound of different salts, is procured by burning large quantities of wood of any kind; and this process is called incineration: the predominating salt, however, is alkaline; and as the neutral trial salts are obtained to better advantage by other means, they are generally neglected in the purification of potashes. Potashes, then, freed from its impurities, and separated from the other salts by processes to be hereafter mentioned, is now

The fixed vegetable Alkali.

Alkalis in general are distinguished by a pungent taste, the very reverse of that of sourness; by their destroying the acidity of every sour liquor; and by their changing the blue and red colours of vegetables to a green: they attract more or less the moisture of the air, and some of them deliquesce. The fixed alkalis, which we shall at present consider more particularly, are fusible by a gentle heat: by a greater degree of heat they are dissipated; their fixity, therefore, is only relative to the other kind of alkalis, viz. the volatile: they dissolve and form glaas with earths: and, lastly, when joined with acids to the point of saturation, they form what are called Neutral Salts.

These characters will afford some necessary and preliminary knowledge of these substances in general; and we shall afterwards find that they are sufficient to distinguish them from all other saline bodies: it is necessary, however, to examine them more minutely, for our analysis has not yet reached so far as to present them in their simplest state. Previous to the discoveries of Dr Black, the vegetable fixed alkali (which we at present speak of particularly), when separated from the foreign matters with which it is mixed in the ashes, was considered to be in its purest state: we shall afterwards find that it is still a compound body, and is really a neutral salt, compounded of pure alkali, and fixed air or the aerial acid. We presume, then, that the particular history of its chemical and medicinal properties will be better understood when we come to those processes by which it is brought to its most pure and simple state: See Chemistry. We shall only therefore observe for the present, that fixed vegetable alkali, not only in its pure state, but also when neutralised by aerial acid, seems always to be one and the same thing, from whatever vegetable it has been produced. Those of some sea-plants must, however, be excepted: the saline matter obtained from these last is, like the former, in a mixed and impure state; it differs, however, from potashes, in containing an alkali of somewhat different properties. The cinder of sea-plants containing this alkali is called

Soda.

Soda, then, as we have just now hinted, is produced by the incineration of the kali and other sea-plants: And from this impure and mixed mass of cinder, is obtained the marine, mineral, or muriatic alkali, or natron, as it is now denominated by the London College. This alkali has acquired these names, because it is the base of the common marine or sea-salt: it differs from the vegetable alkali in being more easily crystallizable; when dried, it does not like the former attract humidity sufficient to form a liquid; it is somewhat less pungent to the taste, and, according to Berghman, has less attraction for acids than the vegetable alkali.

It is, however, to be observed, that this alkali, when deprived of fixed air, that is to say, when brought to its purest state, can scarcely, if at all, be distinguished from the vegetable alkali; and indeed the true distinction can only be formed from their combinations, each of them affording with the same acid very different neutral salts. It belonged to this place to mention some of the characters of alkalis in general, and also some of those marks by which the vegetable and mineral alkalis are distinguished from each other; but for a more particular history of their chemical and medicinal properties, we refer to an account of the pharmaceutical preparations. As the volatile alkali is rarely produced from vegetables, but is generally obtained from animal matter, we shall consider that kind of alkali when we come to analyse the animal kingdom.

Of Vegetable Earth.

After all the saline matter contained in the ashes of vegetables has been wasted off by the processes before mentioned, there yet remains one infusible earthy-like powder, generally of a whitish colour, insoluble in water, and from which some iron may be attracted by the magnet. It is said to have formed alum with the vitriolic acid; a kind of felspar has also been obtained, but somewhat different from that produced by the union of the same acid with calcareous earth; this residuum of burnt vegetables differs also from calcareous earth, in not being susceptible of becoming quicklime by calcination. It has been found that this residuum, instead of an earth, is a calcareous phosphoric salt, similar to that obtained from the bones of animals.

We have thus finished our analysis of vegetables by the naked fire; and have only to observe, that, like the analysis by fermentation, it can afford us no useful information on the native principles of the vegetable itself.

When chemistry began first to be formed into a rational science, and to examine the component parts and internal constitution of bodies, it was imagined, that this resolution of vegetables by fire, discovering us all their active principles, unclogged and unmixed with each other, would afford the surest means of judging of their medicinal powers. But on prosecuting these experiments, it was soon found that they were insufficient for that end: that the analyses of poisonous and efculent plants agreed often as nearly as the analyses of one plant: that by the action of a burning heat, two principles of vegetables are not barely separated, but altered, transposed, and combined into new forms; insomuch that it was impossible to know in what form they existed, and with what qualities they were endowed, before these changes and transpositions happened. If, for example, 32 ounces of a certain vegetable substance are found to yield ten ounces and a half of acid liquor, above one ounce and five drams of oil, and three drams and a half of fixed alkaline salt: what idea can this analysis give of the medicinal qualities of gum Arabic?

III. Substances naturally contained in vegetables, and separable by Art without Alteration of their native Qualities.

It has been supposed, that there is one general fluid or blood which is common to all vegetables, and from which the fluids peculiar to particular plants and their parts are prepared by a kind of secretion: To this supposition posed general fluid botanists have given the name of sap. This opinion is rendered plausible from the analogy in many other respects between vegetable and animal substances; and indeed if we consider the water of vegetation as this general fluid, the opinion is perhaps not very far from the truth; but the notion has been carried much farther than supposing it to be mere water; and the opinion of naturalists on this subject does not seem to be well supported by experience. It is difficult to extract this sap without any mixture of their constituent parts. But in a few vegetables, from which it distils by wounding their bark, we find this supposed general blood possessing properties not a little various: Thus the juice effused from a wounded birch is considerably different from that poured out from an incision in the vine.

1. Grofs Oils.

Vegetables, like animals, contain an oil in two different states. That is, in several vegetables a certain quantity of oil is superabundant to their constitution, is often lodged in distinct reservoirs, and does not enter into the composition of their other principles: in most vegetables, again, another quantity of oil is combined, and makes a constituent part of their principles. Of this last we formerly spoke in our analysis of vegetables by fire; and it is the former we mean to consider, under the three following heads.

Grofs oils abound chiefly in the kernels of fruits, and in certain seeds; from which they are commonly extracted by expression, and are hence distinguished by the name of expressed oils. They are contained also in all the parts of all vegetables that have been examined, and may be forced out by vehemence of fire; but here their qualities are much altered in the process by which they are extracted or discovered, as we have seen under the foregoing head.

These oils, in their common state, are not dissoluble either in vinous spirits or in water, though by means of certain intermedia they may be united both with the one and the other. Thus a skilful interpolation of sugar renders them miscible with water into what are called lochochs and oily draughts; by the intervention of gum or mucilage they unite with water into a milky fluid; by alkaline salts they are changed into a soap, which is miscible both with water and spirituous liquors, and is perfectly dissolved by the latter into an uniform transparent fluid. The addition of any acid to the soapy solution absorbs the alkaline salt; and the oil, which of course separates, is found to have undergone this remarkable change, that it now dissolves without any intermedium in pure spirit of wine.

Expressed oils exposed to the cold lose their fluidity greatly: some of them, in a small degree of cold, congeal into a consistent mass. Kept for some time in a warm air, they become thin and highly rancid: their soft, lubricating, and relaxing quality is changed into a sharp acrimonious one: and in this state, instead of allaying, they occasion irritation; instead of obfusing corrosive humours, they corrode and inflame. These oils are liable to the same noxious alteration while contained in the original subject: hence arises the rancidity which the oily seeds and kernels, as almonds and those called the cold seeds, are so liable to contract in keeping. Nevertheless, on triturating these seeds or kernels with water, the oil, by the intervention of the other matter of the subject, unites with the water, into an emulsion or milky liquor, which, instead of growing rancid, turns sour on standing.

It appears then that some kind of fermentation goes on in the progress of oils in the rancid state; and it would seem from some experiments by Mr Macquer, that an acid is evolved, which renders them more soluble in spirit of wine than before.

In the heat of boiling water, and even in a degree of heat as much exceeding this as the heat of boiling water does that of the human body, these oils suffer little dissipation of their parts. In a greater heat they emit a pungent vapour, seemingly of the acid kind; and when suffered to grow cold again, they are found to have acquired a greater degree of consistence than they had before, together with an acid taste. In a heat approaching to ignition, in close vessels, the greatest part of the oil arises in an empyreumatic state, a black coal remaining behind.

2. Grofs sebaceous matter.

From the kernels of some fruits, as that of the chocolate nut, we obtain, instead of a fluid oil, a substance of a butyraeous consistence; and from others, as the nutmeg, a solid matter as firm as tallow. These concretes are most commodiously extracted by boiling the substance in water: the sebaceous matter, liquefied by the heat, separates and arises to the surface, and refumes its proper consistence as the liquor cools.

The substances of this class have the same general properties with expressed oils, but are less disposed to become rancid in keeping than most of the common fluid oils. It is supposed by the chemists, that their thick consistence is owing to a larger admixture of an acid principle: for, in their resolution by fire, they yield a vapour more sensibly acid than the fluid oils; and fluid oils, by the admixture of concentrated acids, are reduced to a thick or solid mass.

3. Essential Oils.

Essential oils are obtained only from those vegetables, or parts of vegetables, that are considerably odoriferous. They are the direct principle in which the whence odour, and oftentimes the warmth, pungency, and obtained other active powers of the subject, reside; whence their name of effluences or essential oils.

Essential oils are secreted fluids; and are often lodged in one part of the plant, while the rest are entirely void of them. Sometimes they are found in separate spaces or receptacles; and are there visible by the naked eye: thus, in the rind of lemons, oranges, citrons, and many others, there are placed everywhere small pellicular vesicles, which, by pressing the peel near to the flame of a candle, squirt out a quantity of essential oil, forming a stream of lambent flame: hence, too, an oleofaccharum may be made, by rubbing the exterior surface of these peels with a piece of lump sugar, which at once tears open, these vesicles, and absorbs their contained oil.

Essential oils unite with rectified spirit of wine, and compose with it one homogeneous transparent fluid; though some of them require for this purpose a much larger Larger proportion of the spirit than others. The difference of their solubility perhaps depends on the quantity of disengaged acid; that being found by Mr Macquer not only to promote the solution of essential oils, but even of those of the unctuous kind. Water also, though it does not dissolve their whole substance, may be made to imbibe some portion of their more subtile matter, so as to become considerably impregnated with their flavour; by the admixture of sugar, gum, the yolk of an egg, or alkaline salts, they are made totally dissoluble in water. Digested with volatile alkali, they undergo various changes of colour, and some of the less odorous acquire considerable degrees of fragrance; while fixed alkali universally impairs their odour.

The specific gravity of most of these oils is less than that of water; some of them, however, are so heavy as to sink in water; but these varieties shall be noticed when we come to their preparation.

In the heat of boiling water, these oils totally exhale; and on this principle they are commonly extracted from subjects that contain them; for no other fluid, which naturally exists in vegetables, is exhalable by that degree of heat, excepting the aqueous moisture, from which the greatest part of the oil is easily separated. Some of these oils arise with a much less heat, a heat little greater than that in which water begins visibly to evaporate. In their resolution by a burning heat, they differ little from expressed oils.

Essential oils, exposed for some time to a warm air, suffer an alteration very different from that which the expressed undergo. Instead of growing thin, rancid, and acrimonious, they gradually become thick, and at length harden into a solid brittle concrete; with a remarkable diminution of their volatility, fragrancy, pungency, and warm stimulating quality. In this state, they are found to consist of two kinds of matter; a fluid oil, volatile in the heat of boiling water, and nearly of the same quality with the original oil; and of a grosser substance which remains behind, not exhalable without a burning heat, or such as changes its nature, and resolves it into an acid, an empyreumatic oil, and a black coal.

The admixture of a concentrated acid instantly produces, in essential oils, a change nearly similar to that which time effects. In making these kinds of mixtures, the operator ought to be on his guard; for when a strong acid, particularly that of nitre, is poured hastily into an essential oil, a great heat and ebullition ensue, and often an explosion happens, or the mixture bursts into flame. The union of expressed oils with acids is accompanied with much less conflict.

4. Concrete essential oil.

Some vegetables, as roses and eleocharane root, instead of a fluid essential oil, yield a substance possessing the same general properties, but of a thick or sebaceous consistence. This substance appears to be of as great volatility and subtilty of parts as the fluid oils; it equally exhales in the heat of boiling water, and concretes upon the surface of the collected vapour. The total exhalation of this matter, and its concreting again into its original constituent state, without any separation of it into a fluid and a solid part, distinguishes it from essential oils that have been thickened or indurated by age or by acids.

5. Camphor.

Camphor is a solid concrete, obtained chiefly from Camphor, the woody parts of certain Indian trees. It is volatile like essential oils, and soluble both in oils and inflammable spirits; it unites freely with water by the intervention of gum, but very sparingly and imperfectly by the other intermedia that render oils miscible with watery liquors. It differs from the sebaceous as well as fluid essential oils, in suffering no sensible alteration from long keeping; in being totally exhalable, not only by the heat of boiling water, but in a warm air, without any change or separation of its parts, the last particle that remains unexhaled appearing to be of the same nature with the original camphor; in its receiving no empyreumatic impression, and suffering no resolution, from any degree of fire to which it can be exposed in close vessels, though readily combustible in the open air; in being dissolved by concentrated acids into a liquid form; and in several other properties which it is needless to specify in this place.

6. Aroma.

Or spiritus rectus, is the name given to the odoriferous principle of vegetables. These bodies differ greatly from one another in the quantity, strength, and volatility of the odoriferous principle which they contain. It is generally found united with volatile oils; but it is soluble in alcohol and water as well as in these. The slightest degree of heat is sufficient to disengage the aroma of plants. To obtain it, the plant must be distilled in a balneum mariae, and its vapours received into a cold capital, which may condense and afterwards conduct them in a fluid state into the receiver. The product is pure odoriferous water, and is known by the name of essential or distilled water. This liquor is to be considered as a solution of the aroma or odoriferous principle in water. When aromatic water is heated, it loses its smell in consequence of the odoriferous principle being more volatile than the fluid in which it was dissolved. This principle is also diffused by exposure to the air. Many facts would induce us to believe, that the principle of smell is one of the elementary principles of volatile oils; but we are as yet almost completely ignorant of its chemical nature, properties, and combinations.

7. Resin.

Essential oils, indurated by age or acids, are called resins. When the indurated mass has been exposed to the heat of boiling water, till its more subtile part, or the pure essential oil that remained in it, has exhaled, the gross matter left behind is likewise called resin. We find,

(n) It may likewise be procured from most of the volatile oils, by volatilizing the oil in a temperature a few degrees below that which is sufficient to elevate the camphor. Refus in general dissolve in rectified spirit of wine, though some of them much less easily than others; it is chiefly by means of this solvent that they are extracted from the subjects in which they are contained. They dissolve also in oils both expressed and essential; and may be united with watery liquors by means of the same intermedia which render the fluid oils miscible with water. In a heat less than that of boiling water, they melt into an oily fluid; and in this state they may be incorporated one with another. In their resolution by fire, in close vessels, they yield a manifest acid, and a large quantity of empyreumatic oil.

8. Gum.

Gum differs from the foregoing substances in being inflammable; for though it may be burnt to a coal, and thence to ashes, it never yields any flame. It differs remarkably also in the proportion of the principles into which it is resolved by fire; the quantity of empyreumatic oil being far less, and that of an acid far greater. In the heat of boiling water, it suffers no dissipation; nor does it liquefy like resin; but continues unchanged, till the heat be so far increased as to scorch or turn it to a coal.

By a little quantity of water, it is softened into a viscid adhesive mass, called mucilage; by a larger quantity it is dissolved into a fluid, which proves more or less glutinous according to the proportion of gum. It does not dissolve in vinous spirits, or in any kind of oil; nevertheless, when softened with water into a mucilage, it is easily miscible both with the fluid oils and with resins; which by this means become soluble in watery liquors along with the gum, and are thus excellently fitted for medicinal purposes.

This elegant method of uniting oils with aqueous liquors, which has been kept a secret in few hands, appears to have been known to Dr Grew. "I took (says he) oil of aniseeds, and pouring it upon another body, I so ordered it, that it was thereby turned into a perfect milk-white balsam or butter; by which means the oil became mingled with any vinous or watery liquor, easily and instantaneously dissolving therein in the form of a milk. And note, this is done without the least alteration of the smell, taste, nature, or operation of the said oil. By somewhat the same means any other stillatitious oil may be transformed into a milk-white butter, and in like manner be mingled with water or any other liquor; which is of various use in medicine, and what I find oftentimes very convenient and advantageous to be done." (Grew of Mixture, chap. v. inf. i. § 7.) This inquiry has lately been further prosecuted in the first volume of the Medical Observations published by a society of physicians in London; where various experiments are related, for rendering oils, both essential and expressed, and different unctuous and resinous bodies, soluble in water by the mediation of gum. Mucilages have also been used for suspending crude mercury, and some other ponderous and insoluble substances: the mercury is by this means not a little divided; but it is found that the particles are very apt to run together or subside, if a pretty constant agitation be not kept up.

As oily and resinous substances are thus united to water by the means of gum, so gums may in like manner be united to spirit of wine by the intervention of resins and essential oils; though the spirit does not take up near so much of the gum as water does of the oil or resin.

Acid liquors, though they thicken pure oils, or render them consistant, do not impede the dissolution of gum, or of oils blended with gum. Alkaline salts, on the contrary, both fixed and volatile, though they render pure oils soluble in water, prevent the solution of gum, and of mixtures of gum and oil. If any pure gum be dissolved in water, the addition of any alkali will occasion the gum to separate, and fall to the bottom in a consistant form; if any oily or resinous body was previously blended with the gum, this also separates, and either sinks to the bottom, or rises to the top, according to its gravity.

9. Gum-resin.

By gum-resin is understood a mixture of gum and resin. Many vegetables contain mixtures of this kind, of what in which the component parts are so intimately united, compound with the interposition perhaps of some other matter, that the compound, in a pharmaceutical view, may be considered as a distinct kind of principle; the whole mass dissolving almost equally in aqueous and in spirituous liquors; and the solutions being not turbid or milky, like those of the grossest mixtures of gum and resin, but perfectly transparent. Such is the adherent matter of bitart-root, and the bitter matter of gentian. It were to be wished that we had some particular name for this kind of matter; as the term gum resin is appropriated to the grossest mixtures, in which the gummy and resinous parts are but loosely joined, and easily separable from each other.

We shall afterwards find that it will be convenient to imitate this natural combination by art. As the effects of medicines very generally depend on their solubility in the stomach, it is often necessary to bring their more insoluble parts, such as resinous and oily matters, into the state of gum-resin: this is done, as we have mentioned in the former article, by the mediation of mucilage. By this management these matters become much more soluble in the stomach; and the liquor thus prepared is called an emulsion, from its whitish colour, resembling that of milk.

10. Saline Matter.

Of the saline juices of vegetables there are different kinds, which have hitherto been but little examined: the sweet and the acid ones are the most plentiful and the best known.

There have lately, however, been discovered a considerable variety of salts in different vegetables. The salt in vegetable alkali, which was formerly considered as a product of the fire, has been obtained from almost all plants by macerating them in acids; the vegetable alkali is the most common, but the mineral is also found in the marine plants. Besides the fixed alkali, several other salts have been detected in different vegetables; such as vitriolated tartar, common salt, Glauber's salt, nitre, felspar, salt, and selenite. From some some experiments, too, the volatile alkali has been supposed to exist ready formed in many plants of the cruciflor or tetradynamian tribe.

It is, however, to be understood, that though some of these salts are really products of vegetation, others of them are not unfrequently adventitious, being imbibed from the soil without any change produced by the functions of the vegetable.

The juices of vegetables, exposed to a heat equal to that of boiling water, suffer generally no other change than the evaporation of their watery parts; the saline matter remaining behind, with such of the other fixed parts as were blended with it in the juice. From many plants, after the exhalation of great part of the water, the saline matter gradually separates in keeping, and concretes into little solid masses, leaving the other substances dissolved or in a moist state; from others, no means have yet been found of obtaining a pure concrete salt.

The salts more peculiarly native and essential to vegetables are the sweet and the sour; these two are frequently blended together in the same vegetable, and sometimes pass into each other at different ages of the plant. Of the four salts several kinds are known in pharmacy and in the arts; such as those of sorrel, of lemons, oranges, citrons, &c. The saccharine salts are also obtained from a great number of vegetables; they may in general be easily discovered by their sweet taste: the sugar-cane is the vegetable from which this saline matter is procured in greatest quantity, and with most profit in commerce. For its medicinal and chemical properties, see Materia Medica, Art. VII.

The sweet and sour above-mentioned dissolve not only in water, like other saline bodies, but many of them, particularly the sweet, in rectified spirit also. The gross oily and gummy matter, with which they are almost always accompanied in the subject, dissolves freely along with them in water, but is by spirit in great measure left behind. Such heterogeneous matters as the spirit takes up, are almost completely retained by it, while the salt concretes; but of those which water takes up, a considerable part always adheres to the salt. Hence essential salts, as they are called, prepared in the common manner from the watery juices of vegetables, are always found to partake largely of the other soluble principles of the subject; while those extracted by spirit of wine are more pure. By means of rectified spirit, some productions of this kind may be freed from their impurities. Perfect saccharine concretions obtained from many of our indigenous sweets may be thus purified.

There is another kind of saline matter obtained from some resinous bodies, particularly from benzoin, which is of a different nature from the foregoing, and supposed by some of the chemists to be a part of the essential oil of the resin, coagulated by an acid, with the acid more predominant or more engendered than in the other kinds of coagulated or indurated oils. These concretions dissolve both in water and in vinous spirits, though difficultly and sparingly in both: they show several evident marks of acidity, have a smell like that of the resin from which they are obtained, exhale in a heat equal to that of boiling water, or a little greater, and are inflammable in the fire.

This substance partakes of the nature of gum, but has more taste, is more fermentable, and much more nutritive. It abounds in very many vegetables, and is generally deposited in certain parts, seemingly for the purpose of its being more advantageously accommodated to their nourishment and growth. Several of the bulbous and other roots, such as those of potatoes, briony, those from which caffava is extracted, salsify, and many others, contain a great quantity of white saccharine resembling and really possessing the properties of farina. The plants of the leguminous tribe, such as peas and beans, are found also to abound with this matter. But the largest quantity of farina resides in grains, which are therefore called farinaceous. Of this kind are wheat, rye, barley, oats, rice, and other similar plants.

At first sight farina appears to be one homogeneous Farina, of substance: it is, however, found to be a compound of what compose three different and separable parts. To illustrate this, we shall take as an example the farina of wheat, being the vegetable which affords it in greatest quantity, and in its most perfect state. To separate these different parts we form a paste with any quantity of flour and cold water; we suspend this paste in a bag of muslin or such like cloth; we next let fall on it a stream of cold water from some height, and the bag may now and then be very gently squeezed; the water in its descent carries down with it a very fine white powder, which is received along with the water in a vessel placed below the bag: the process must be continued till no more of this white powder comes off, which is known by the water that passes through the bag ceasing to be of a milky colour. The process being now finished, the farina is found to be separated into three different substances: the glutinous or vegeto-animal part remains in the bag; the amyloid or starch is deposited from the water which has been received in the vessel placed below the bag; and, lastly, a mucous matter is held dissolved in the same water from which the starch has been deposited: this mucous part may be brought to the consistence of honey, by evaporating the water in which it is kept in solution.

These several parts are found also to differ remarkably in their sensible and chemical properties. The vegeto-animal part is of a whitish grey colour, is tenacious, ductile, and elastic matter, partly possessing the texture of animal membranes. Distilled in a retort, it yields, like all animal matters, a true volatile alkali; and its coal affords no fixed alkali. It is not only infusible, but even indiffusible, in water; both which appear from its remaining in the bag after long-continued lotions. Like gums, it is infusible in alcohol, in oils, or ether; but it is also infusible in water, and yields on distillation products very different from those afforded by gums: it is therefore of an animal nature, and approaches perhaps nearer to the coagulable lymph of animals than to any other substance.

The fixed alkali, by means of heat, dissolves the glutinous vegeto-animal; but when it is precipitated from this solution by means of acids, it is found to have lost its elasticity. The mineral acids, and especially the nitrous, nitrous, are also capable of dissolving the vegeto-animal part of the farina.

The starch, amyllum, or the amylaceous matter, makes the principal part of the farina. As we before noticed, it is that fine powder deposited from the water which has pervaded the entire farina: it is of a greyish white colour, but can be rendered much whiter by making it undergo a certain degree of fermentation. Starch is insoluble in cold water; but in hot water it forms a transparent glue: hence the necessity of employing cold water in separating it from the vegeto-animal part. Distilled in a retort, it yields an acid phlegm; and its coal affords, like other vegetables, a fixed alkaline salt. As starch forms the greatest part of the farina, it is probably the principal nutritive constituent in bread.

The mucous, or rather the mucoso-saccharine matter, is only in a very small quantity in bread. This substance on distillation is found to exhibit the phenomena of sugar. The use of this matter seems to be that of producing the vinous fermentation; and we may observe once for all, that the preparation of good bread probably depends on a proper proportion of the three different parts above described; viz. that the vinous fermentation is promoted by the mucoso-saccharine part, the acetons by the starch, and the putrid by the gluten vegeto-animale. From different states or degrees of these several stages of fermentation the qualities of good bread are probably derived.

12. Of the Colouring Matter of Vegetables.

The colouring matter of vegetables seems to be of an intermediate nature between the gummy and resinous parts. It is in many plants equally well extracted by water, and by rectified spirit: it is also, however, procurable in the form of a lake, not at all soluble in either of these menstrua. It would seem that the colouring matter, strictly called, has hitherto eluded the researches of chemists. It is only the base or nidus, in which the real colouring matter is embodied, that chemistry has as yet reached; and on the chemical properties of this base, colours are capable of being extracted by different menstrua, and of being variously accommodated to the purposes of dying. The substance from which the colours of vegetables are immediately derived, is without doubt a very volatile body. Since plants are known to lose their colour when excluded from the light of the sun, there is reason to think that the immediately colouring substance is primarily derived from the matter of the sun, somewhat elaborated by vegetable life.

Many of these dyes are evolved or variously modified by chemical operations. Thus a colouring matter is somewhat deposited in the form of a floccula during the putrefaction of the vegetable; in others it is evolved or changed by alum, by acids, or by alkali. We may also observe, that any part of the vegetable may be the base of the colouring matter. This appears from the solubility of the different dyes in their proper menstrua; and in these solutions we have not been able to separate the real colouring matter from the base in which it is invested. After all, then, we must conclude, that a full investigation of this subject more properly belongs to the sublimer parts of Chemistry, than to the business in which we are at present engaged.

The colouring drugs are considered in their proper places.

In finishing our history of the vegetable kingdom, it only remains that we should offer some

General Observations on the foregoing Principles.

1. Essential oils, as already observed, are obtainable only from a few vegetables: but grols oil, resin, gum, and saline matter, appear to be common, in greater or less proportion, to all; some abounding more with one and others with another.

2. The several principles are in many cases intimately combined; so as to be extracted together from the subject, by those dissolvents, in which some of them separately could not be dissolved. Hence watery infusions and spirituous tinctures of a plant, contain respectively more substances than those of which water or spirit is the proper dissolvent.

3. After a plant has been sufficiently infused in water, all that spirit extracts from the residuum may be considered as consisting wholly of such matter as directly belongs to the action of spirit. And, on the contrary, when spirit is applied first, all that water extracts afterwards may be considered as consisting only of that matter of which water is the direct dissolvent.

4. If a vegetable substance, containing all the principles we have enumerated, be boiled in water, the essential oil, whether fluid or concrete, and the camphor, and volatile essential salt, will gradually exhale with the steam of the water, and may be collected by receiving the steam in proper vessels placed beyond the action of the heat. The other principles not being volatile in this degree of heat, remain behind: the grols oil and sebaceous matter float on the top: the gummy and saline substance, and a part of the resin, are dissolved by the water, and may be obtained in a solid form by straining the liquor, and exposing it to a gentle heat till the water has exhaled. The rest of the resin, still retained by the subject, may be extracted by spirit of wine, and separated in its proper form by exhaling the spirit. On these foundations most of the substances contained in vegetables may be extracted, and obtained in a pure state, however they may be compounded together in the subject.

5. Sometimes one or more of the principles is found naturally disengaged from the others, lying in distinct receptacles within the subject, or extravasated and accumulated on the surface. Thus, in the dried roots of angelica, cut longitudinally, the microscope discovers veins of resin. In the flower cups of hypericum, and the leaves of the orange-tree, transparent points are distinguished by the naked eye: which, at first view, seem to be ho's, but on a closer examination are found to be little vehicles filled with essential oil. In the bark of the fir, pine, larch, and some other trees, the oily receptacles are extremely numerous, and so copiously supplied with the oily and resinous fluid, that they frequently burst, especially in the warm climates, and discharge their contents in great quantities. The acacia tree in Egypt, and the plum and cherry among ourselves, yield almost pure gummy exudations. From a species of ash is secreted the saline sweet substance manna; and the only kind of sugar with which the ancients were acquainted, appears to have been a natural exudation from the cane.

6. The foregoing principles are, as far as is known, all that naturally exist in vegetables; and all that art can extract from them, without such operations as change their nature, and destroy their original qualities. In one or more of these principles, the colour, smell, taste, and medicinal virtues, of the subject, are almost always found concentrated.

7. In some vegetables the whole medicinal activity resides in one principle. Thus, in sweet almonds, the only medicinal principle is a grofs oil; in horse-radish root, an essential oil; in jalap root, a resin; in marsh mallow root, a gum; in the leaves of sorrel, a saline acid substance.

8. Others have one kind of virtue residing in one principle, and another in another. Thus Peruvian bark has an astringent resin and a bitter gum; wormwood a strong flavoured essential oil and a bitter gum resin.

9. The grofs infipid oils and sebaceous matters, the simple infipid gums, and the sweet and acid saline substances, seem to agree both in their medicinal qualities and in their pharmaceutic properties.

10. But essential oils, resins, and gum-resins, differ much in different subjects. As essential oils are universally the principle of odour in vegetables, it is obvious that they must differ in this respect as much as the subjects from which they are obtained. Resins frequently partake of the oil, and consequently of the differences depending on it; with this further diversity, that the grofs resinous part often contains other powers than those which reside in oils. Thus from wormwood a resin may be prepared, containing not only the strong smell and flavour but likewise the whole bitterness of the herb; from which last quality the oil is entirely free. The bitter, astringent, purgative, and emetic virtue of vegetables, reside generally in different sorts of resinous matter, either pure or blended with gummy and saline parts; of which kind of combinations there are many to intimate, that the component parts can scarcely be separated from each other, the whole compound dissolving almost equally in aqueous and spirituous menstrua.

11. There are some substances also, which, from their being totally soluble in water, and not in spirit, may be esteemed to be mere gums; but which, nevertheless, possess virtues never to be found in the simple gums. Such are the astringent gum called acacia, and the purgative gum extracted from aloes.

12. It is supposed that vegetables contain certain subtle principles different in different plants, of too great tenacity to be collected in their pure state, and of which oils, gums, and resins, are only the matrices or vehicles. This inquiry is foreign to the purposes of pharmacy, which is concerned only about grofsier and more sensible objects. When we obtain from an odoriferous plant an essential oil, containing in a small compass the whole fragrance of a large quantity of the subject, our intentions are equally answered, whether the substance of the oil be the direct odorous matter, or whether it has diffused through it a fragrant principle more subtle than itself. And when this oil in long keeping loses its odour, and becomes a resin, it is equal in regard to the present considerations, whether the effect happens from the avolition of a subtle principle, or from a change produced in the substance of the oil itself.

Sect. II. Animals.

From the history we have already given of the vegetable kingdom, our details on animal substances may of animal in many particulars be considerably abridged. All substances, animals are fed on vegetables, either directly or by the intervention of other animals. No part of their substance is derived from any other source except water. The small quantity of salt used by man and some other animals, is only necessary as a cleansing or stimulus to the stomach. As the animal then is derived from the vegetable matter, we accordingly find that the former is capable of being resolved into the same principles as those of the latter. Thus, by repeated distillations, we obtain from animal substances, water, oil, air, an easily destructible salt, and charcoal. These secondary principles are by farther processes at length reducible into the same proximate principles which we found in vegetables, viz. water, air, earth, and the principle of inflammability. But though the principles of vegetable and animal substances are fundamentally the same, yet these principles are combined in a very different manner. It is exceedingly rare that animal substances are capable of the vinous or acetous fermentations; and the putrefactive, into which they run remarkably fast, is also different in some particulars from the putrefaction of vegetables; the escape of the phlogiston in the form of light is more evident, and the smell is much more offensive, in the putrefaction of animal than of vegetable substances. The putrefaction of urine is indeed accompanied with a peculiar fetor, by no means so intolerable as that of other animal matters: this we suppose to be owing to the pungency derived from the volatile alkali, and also to the urine containing less inflammable matter than the blood and many other fluids. When analysed by a destructive heat, animals afford products very different from those of vegetables: the empyreumatic oil has a particular and much more fetid odour; and the volatile salt, instead of being an acid, as it is in most vegetables, is found in animals to be a volatile alkali. Chemists have spoken of an acid procurable from animal substances; and indeed certain parts of animal bodies are found to yield a salt of this kind; but it by no means holds with animal substances in general; and though the proofs to the contrary were even conclusive, it is confessedly in so small a quantity as not to deserve any particular regard. In some animals, however, an acid exists, uncombined and ready formed in their bodies. This is particularly manifest in some insects, especially ants, from which an acid resembling the acetous has been procured by boiling them in water. The solid parts of animal bodies, as the muscles, teguments, tendons, cartilages, and even the bones, when boiled with water, give a gelatinous matter or glue resembling the vegetable gums, but much more adhesive. We must, however, except the horny parts and the hair, which seem to be little soluble either in water or in the liquors of the stomach. The acids, the alkalis, and quicklime, are also found to be powerful solvents of animal matters. It is from the solid parts parts that the greatest quantity of volatile alkali is obtained; it arises along with a very fetid empyreumatic oil, from which it is in some measure separated by repeated rectifications. This salt is partly in a fluid, and partly in a concrete state; and from its having been anciently prepared in the greatest quantity from the horns of the hart, it has been called salt or spirit of hart's horn. Volatile alkali is, however, procurable from all animals, and from almost every part of animal bodies except fat. Though we are sometimes able to procure fixed alkali from an animal cinder, yet it is probable that this salt did not make any part of the living animal, but rather proceeded from the introduction of some saline matter, incapable of being assimilated by the functions of the living creature.

In speaking of the fluid parts of animals, we should first examine the general fluid, or blood, from whence the rest are secreted. The blood, which at first sight appears to be an homogeneous fluid, is composed of several parts, easily separable from each other, and which the microscope can even perceive in its uncoagulated state. On allowing it to stand at rest, and to be exposed to the air, it separates into what are called the crassamentum and the serum. The crassamentum, or cruor, chiefly consists of the red globules, joined together by another substance, called the coagulable lymph; the chemical properties of these globules are not as yet understood; but they seem to contain the greatest quantity of the iron found in the blood. The serum is a yellowish subacid liquor, having little sensible taste or smell; at a heat of 160° Fahrenheit, it is converted into a jelly. This coagulation of the serum is also owing to its containing a matter of the same nature with that in the crassamentum, viz., the coagulable lymph: whatever then coagulates animal blood, produces that effect on this concretable part. Several causes, and many different substances, are capable of effecting this coagulation; such as contact of air, heat, alcohol, mineral acids, and their combinations with earths, as alum, and some of the metallic salts. The more perfect neutral salts are found to prevent the coagulation, such as common salt and nitre.

Of the fluids secreted from the blood, there are a great variety in men and other animals. The excrementitious and redundant fluids are those which afford in general the greatest quantity of volatile alkali and empyreumatic oil; there are also some of the secreted fluids, which, on a chemical analysis, yield products in some degree peculiar to themselves. Of this kind is the urine, which is found to contain in the greatest abundance the noted salt formed from the phosphoric acid and volatile alkali. The fat, too, has been said to differ from the other animal matters, in yielding by distillation a strong acid, but no volatile alkali. There is also much variety in the quantity and state of the combination of the saline and other matters in different secreted fluids. But for a fuller investigation of this and other parts of the subject, we refer to Anatomy, Chemistry, and Physiology; with which it is more immediately connected than with the elements of pharmacy.

Animal oils and fats, like the gross oils of vegetables, are not of themselves soluble either in water or vinous spirits; but they may be united with water by the intervention of gum or mucilage. Most of them may be changed into soap, by fixed alkaline salts; Elements and be thus rendered miscible with spirit as well as water.

The odoriferous matter of some odoriferous animal substances, as musk, civet, castor, is, like essential oil, insoluble in spirit of wine, and volatile in the heat of boiling water. Carthager relates, that from castor an animal essential oil has been obtained in a very small quantity, but of an exceedingly strong diffusive smell.

The vesicating matter of cantharides, and those parts of sundry animal substances in which their peculiar taste resides, are dissolved by rectified spirit, and seem to have some analogy with resins and gummy resins.

The gelatinous principle of animals, like the gum of vegetables, dissolves in water, but not in spirit or in oils; like gums also, it renders oils and fats miscible with water into a milky liquor.

Some insects, particularly the ant, are found to contain an acid juice, which approaches nearly to the nature of vegetable acids.

There are, however, sundry animal juices, which differ greatly, even in these general kinds of properties, from the corresponding ones of vegetables. Thus animal serum, which appears analogous to vegetable gummy juices, has this remarkable difference, that though it mingles uniformly with cold or warm water, yet on considerably heating the mixture, the animal-matter separates from the watery fluid, and concretions into a solid mass. Some physicians have been apprehensive, that the heat of the body, in certain diseases, might rise to such a degree, as to produce this dangerous or mortal concretion of the serous humours; but the heat requisite for this effect is greater than the human body appears capable of sustaining, being nearly about the middle point between the greatest human heat commonly observed and that of boiling water.

The soft and fluid parts of animals are strongly disposed to run into putrefaction; they putrefy much sooner than vegetable matters; and when corrupted, prove more offensive.

This process takes place, in some degree, in the bodies of living animals, as often as the juices stagnate long, or are prevented, by an obstruction of the natural emunctories, from throwing off their more volatile and corruptible parts.

During putrefaction, a quantity of air is generated; all the humours become gradually thinner, and the fibrous parts more lax and tender. Hence the tympany, which succeeds the corruption of any of the viscera, or the imprudent suppression of dysenteries by astringents; and the weakness and laxity of the vessels observable in scurvy, &c.

The crassamentum of human blood changes by putrefaction into a dark livid-coloured liquor; a few drops of which tinge the serum with a tawny hue, like the ichor of sores and dysenteric fluxes, as also the white of the eye, the saliva, the serum of blood drawn from a vein, and the liquor that oozes from a blister in deep scurvy and the advanced stage of malignant fevers.

The putrid crassamentum changes a large quantity of recent urine to a flame-coloured water, so common in fevers and in the scurvy. This mixture, after standing an hour or two, gathers a cloud resembling what is seen in the crude water of acute distempers, with some oily matter on the surface like the scum which floats on scorbatic urine.

The serum of the blood deposites, in putrefaction, a sediment resembling well-digested pus, and changes to a faint olive-green. A serum so far putrefied as to become green, is perhaps never to be seen in the vessels of living animals; but in dead bodies this serum is to be distinguished by the green colour which the flesh acquires in corrupting. In salted meats, this is commonly ascribed to the brine, but erroneously; for that has no power of giving this colour, but only of qualifying the taste, and in some degree, the ill effects of corrupted aliment. In foul ulcers and other sores, where the serum is left to stagnate long, the matter is likewise found of this colour, and is then always acrimonious.

The putrefaction of animal substances is prevented or retarded by most saline matters, even by the fixed and volatile alkaline salts, which have generally been supposed to produce a contrary effect. Of all the salts that have been made trial of, sea-salt seems to resist putrefaction the least; in small quantities it even accelerates the process. The vegetable bitters, as chamomile flowers, are much stronger antiseptics, not only preserving flesh long uncorrupted, but likewise somewhat correcting it when putrid: the mineral acids have this last effect in a more remarkable degree. Vivous spirits, aromatic and warm substances, and the acid plants, falsely called alkalis, as soury-grass and horseradish, are found also to resist putrefaction. Sugar and camphor are found to be powerfully antiseptic. Fixed air, or the aerial acid, is likewise thought to resist putrefaction; but above all the vapours of nitrous acid, in the form of air (the nitrous air of Dr Pringle), is found to be the most effectual in preserving animal bodies from corruption. The list of the septic, or of those substances that promote putrefaction, is very short; and such a property has only been discovered in calcareous earths and magnesia, and a very few salts, whose bases are of these earths.

It is observable, that notwithstanding the strong tendency of animal matters to putrefaction, yet broths made from them, with the admixture of vegetables, instead of putrefying turn sour. Sir John Pringle has found, that when animal flesh in substance is beaten up with bread or other farinaceous vegetables, and a proper quantity of water, into the consistence of a pap, this mixture likewise, kept in a heat equal to that of the human body, grows in a little time sour; while the vegetable matters, without the flesh, suffer no such change.

It was observed in the preceding section, that some few vegetable, in the resolution of them by fire, discover some agreement in the matter with bodies of the animal kingdom; yielding a volatile alkaline salt in considerable quantity, with little or nothing of the acid or fixed alkali, which the generality of vegetables afford. In animal substances also, there are some exceptions to the general analysis: from animal fats, as we before observed, instead of a volatile alkali, an acid liquor is obtained; and their empyreumatic oil wants the peculiar offensiveness of the other animal-oils.

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**Sect. III. Minerals.**

I. Oils and Bitumens.

In the mineral kingdom is found a fluid oil called Oils of the naphtha or petroleum, floating on the surface of waters, mineral or issuing from clefts of rocks, particularly in the eastern countries, of a strong smell, very different from that of vegetable or animal oils, limpid almost as water, highly inflammable, not soluble in spirit of wine, and more averse to union with water than any other oils.

There are different sorts of these mineral oils, more or less tinged, of a more or less agreeable, and a stronger or weaker, smell. By the admixture of concentrated acids, which raise no great heat or conflict with them, they become thick, and at length consistent; and in these states are called bitumens.

These thickened or concreted oils, like the corresponding products of the vegetable kingdom, are generally soluble in spirit of wine, but much more difficultly, more sparingly, and for the most part only partially; they liquefy by heat, but require the heat to be considerably stronger than vegetable products. Their forms are various; but all of them, either in the natural state, when melted or set on fire, yield a peculiar kind of strong scent, called from them bituminous.

The solid bitumens are, amber, jet, asphaltum, or Bitumen, bitumen of Judea, and fossil or pit coal. All these bitumens, when distilled, give out an odorous phlegm, or water, more or less coloured and saline; an acid, frequently in a concrete state; an oil, at first resembling the native petrolea, but soon becoming heavier and thicker; and, lastly, a quantity of volatile alkali is obtained: the residuum is a charry matter, differing in its appearances according to the nature of the bitumen which had been analysed.

From the observations of several naturalists, it is probable that all bitumens are of vegetable and animal origin; that the circumstances by which they differ from the resinous and other oily matters of vegetables and animals, are the natural effects of time, or of an alteration produced on them by mineral acids; or perhaps they are the effect of both these causes combined. This opinion is the more probable, since bitumens, on a chemical analysis, yield oil and volatile alkali; neither of which are found in any other minerals.

II. Earths.

The little impropriety of joining the vegetable and animal earths to the mineral, must be overlooked for the sake of bringing both under one synoptical view. Under the mineral earths are included stones; these earths being no other than earths in an indurated state.—The different kinds of these bodies hitherto taken notice of are the following.

1st, Earths soluble in the nitrous, marine, and vegetable acids, but not at all, or exceeding sparingly, in the nitric acid. When previously dissolved in other acids, they are precipitated by the addition of this last, which thus unites with them into infusible, or nearly infusible concretes, not diffusible in any liquor. Of this kind are,

1. The mineral calcareous earth: distinguished by its being convertible in a strong fire, without addition, into an acrimonious calx called quicklime. This earth occurs in a variety of forms in the mineral kingdom: the fine soft chalk, the coarser limestones, the hard marbles, the transparent spars, the earthy matter contained in waters, and which separating from them incrustates the sides of the caverns, or hangs in icicles from the top, receiving from its different appearances different appellations. How strongly forever some of these bodies have been recommended for particular medicinal purposes, they are fundamentally no other than different forms of this calcareous earth; simple pulverization depriving them of the superficial characters by which they were distinguished in the mass. Most of them generally contain a greater or less admixture of some of the indissoluble kinds of earth; which, however, affects their medicinal qualities no otherwise than by the addition which it makes to their bulk. Chalk appears to be one of the purest; and is therefore in general preferred. They all burn into a strong quicklime; in this state a part of them dissolves in water, which thus becomes impregnated with the astringent and lithontriptic powers that have been erroneously ascribed to some of the earths in their natural state.

During the calcination of calcareous earths, a large quantity of elastic vapour is discharged: the absence of this fluid is the cause of the causticity of quicklime, and of its solubility in water in the form of lime-water. For a more full inquiry into this subject, see Fixed Air, &c.

2. The animal calcareous earth: burning into quicklime like the mineral. Of this kind are oyster-shells and all the marine shells that have been examined; though with some variation in the strength of the quicklime produced from them.

3. The earth of bones and horns: not at all burning into quicklime. This kind of earth is more difficult of solution in acids than either of the preceding. It is accompanied in the subjects with a quantity of gelatinous matter, which may be separated by long boiling in water, and more perfectly by burning in the open air. The earth may be extracted also from the bone or horn, though difficultly, by means of acids; whereas vegetables and the soft parts of animals yield their pure earth by burning only.

2d. Earths soluble with ease in the vitriolic as well as other acids, and yielding, in all other combinations thereof, with saline concretes soluble in water.

1. Magnesia alba: composing with the vitriolic acid a bitter purgative salt. This earth has not yet been found naturally in a pure state. It is obtained from the purging mineral waters and their salts; from the bitter liquor which remains after the crystallization of sea-salt from sea-water; and from the fluid which remains uncrystallized in the putrefaction of some sorts of rough nitre. The ashes of vegetables appear to be nearly the same kind of earth.

2. Aluminous earth: composing with the vitriolic acid a very astringent salt. This earth also has not been found naturally pure. It is obtained from alum; which is no other than a combination of it with the vitriolic acid; it may likewise be extracted, by strong boiling in that acid, from clays and boles.

3d. Earths which by dissolving in acids, either in the cold or in a moderate warmth, are not at all dissolved.

1. Argillaceous earth: becoming hard, or acquiring an additional hardness, in the fire. Of this kind of earth there are several varieties, differing in some particular properties: as the purer clays, which when moistened with water form a very viscous mass, difficultly diffusible through a larger quantity of the fluid, and slowly subduing from it; bole, less viscous, more readily miscible with water, and more readily subduing; and ochre, which have little or nothing of the viscosity of the two foregoing, and are commonly impregnated with a yellow or red ferruginous calx.

2. Cristalline earth: naturally hard, so as to strike sparks with steel; becoming friable in a strong fire. Of this kind are flints, crystals, &c., which appear to consist of one and the same earth, differing in the purity, hardness, and transparency of the mass.

3. Gypseous earth: reducible by a gentle heat into a soft powder, which unites with water into a mass, somewhat viscous and tenacious while moist, but quickly drying and becoming hard. A greater heat deprives the powder of this property, without occasioning any other alteration. Such are the transparent selenites; the fibrous stony masses improperly called English tale; and the granulated gypsum or plaster of Paris stones. Though these bodies, however, have been commonly thought to be mere earths, of a distinct kind from the rest, they appear, both from analytical and synthetical experiments, to be no other than combinations of the mineral calcareous earth with vitriolic acid.

4. Talky earth: scarcely alterable by a vehement fire. The masses of this earth are generally of a fibrous or leafy texture; more or less pellucid, bright or glittering, smooth and unctuous to the touch; too flexible and elastic to be easily pulverized; soft, so as to be cut with a knife. In these respects some of the gypseous earths nearly resemble them, but the difference is readily discovered by fire; a weak heat reducing the gypseous to powder, while the strongest makes no other alteration in the talky, than somewhat diminishing their flexibility, brightness, and unctuousness.

III. Metals.

Of metals, the next division of mineral bodies, the most obvious characters are, their peculiar bright perfect aspect, perfect opacity, and great weight; the lightest of them is six, and the heaviest upwards of 19 times heavier than an equal bulk of water.

To understand the writers in chemistry, it is proper to be informed, that metals are subdivided into the perfect, the imperfect, and the semimetals.

Those possessed of ductility and malleability, and which are not sensibly altered by very violent degrees of heat, are called perfect metals: Of these there are three; gold, silver, and platina. It is, however, probable, that the mark of their indestructibility by fire is only relative: and indeed modern chemists have been able, by a very intense degree of heat, to bring gold into the state of a calx, or something very nearly resembling it. Those metallic substances which possess the distinctive properties of the perfect metals, but in a less degree, are called the imperfect metals: These are, copper, iron, tin, lead.

Lastly, those bodies having the metallic characters in the most imperfect state, that is to say, those which have no ductility and the least fixity in the fire, are distinguished by the name of semi-metals: These are, regulus of antimony, bismuth, zinc, regulus of cobalt, nickel, and regulus of arsenic; which last might be rather considered as the boundary between the metallic and the saline bodies.

Mercury has been generally ranked in a class by itself.

All metallic bodies, when heated in close vessels, melt or fuse. This fusion takes place at different degrees of heat in different metals; and it does not appear that this process produces any change in the metals, provided it be conducted in close vessels. Metals, exposed to the combined action of air and fire, are converted into an earth-like substance called calx: by this process, which we call calcination, the metal suffers remarkable changes. From the distinctive marks we have before given of the metallic bodies, it will be obvious, that the perfect metals are most slowly, the imperfect more quickly, and the semi-metals most easily and soonest affected in this operation. This earth-like powder, or calx, is found to possess no metallic aspect, but is considerably heavier than the metal before its calcination: it has no longer any affinity with metallic bodies, nor even with the metal from which it has been produced.

Besides this method of calcining metals by air and fire, they may likewise be brought into the state of a calx, by dissolving them in acids, from which they may be afterwards freed by evaporating the acid, or by adding to the solution an alkaline salt. Metals are also sometimes dephtogitated by detonation with nitre. This change in their obvious properties is generally accompanied with a remarkable alteration in their medicinal virtues: thus quicksilver, which taken into the body in its crude state and undivided, seems inactive; proves, when calcined by fire, even in small doses, a strong emetic and cathartic, and in smaller ones, a powerful alternative in chronic disorders; while regulus of antimony, on the contrary, is changed by the same treatment, from a high degree of virulence to a state of inactivity.

Calces of mercury and arsenic exhale in a heat below ignition: those of lead and bismuth, in a red or low white heat, run into a transparent glass; the others are not at all vitreifiable, or not without extreme vehemence of fire. Both the calces and glasses recover their metallic form and qualities again by the skilful addition of any kind of inflammable substance that does not contain a mineral acid. This recovery of the metallic calces into the metallic form is called reduction. During this process an elastic aerial fluid escapes, which is found to be pure air.

Is the conversion of metals into calces owing to the discharge of phlogiston, or to the absorption of pure air? And is the reduction to be ascribed to the absorption of phlogiston, or to the escape of pure air? And again, is the calcination to be explained by the discharge of phlogiston and consequent precipitation of pure air? And is the reduction effected by the absorption of phlogiston, either furnished by inflammable bodies or precipitated in consequence of the discharge of pure air? On these questions there is much dispute among modern chemists: We thought it only necessary to state them here, as a full inquiry into the subject is by no means the province of pharmacy. We, however, think it prudent to retain the doctrine of Stahl: and we do this the more readily, because it has been followed in our article Chemistry, and because it is abundantly clear in its illustration of the pharmaceutical processes. We do not mean, however, to reject any modern discovery which may serve to illustrate our subjects.

All metallic bodies dissolve in acids; some only in particular acids, as silver and lead in the nitrous: some only in compositions of acids, as gold in a mixture of the nitrous and marine: and others, as iron and zinc, in all acids. Some likewise dissolve in alkaline liquors, as copper: and others, as lead, in expressed oils. Fused with a composition of sulphur and fixed alkaline salt, they are all, except zinc, made soluble in water.

All metallic substances, dissolved in saline liquors, have powerful effects in the human body, though many of them appear in their pure state to be inactive. Their activity is generally in proportion to the quantity of acid combined with them: Thus lead, which in its crude form has no sensible effect, when united with a small portion of vegetable acid into ceruus, discovers a low degree of the lyptic and malignant quality, which it so strongly exerts when blended with a larger quantity of the same acid into what was called facebarum salutum, but now more properly sal plumbi, or plumbum acetatum: and thus mercury, with a certain quantity of the marine acid, forms the violent corrosive sublimate, which by diminishing the proportion of acid becomes the mild medicine called mercurius dulcis.

IV. Acids.

The salts of this order are very numerous; but as we are at present treating of Minerals, it is only there, on the fore the mineral or solid acids we mean to speak of in various acids.

These are distinguished by the names of the concretes from which they have been principally extracted; the vitriolic from vitriol, the nitrous from nitre or saltpetre; and the marine or muriatic from common sea-fall. The form they are generally in, is that of a watery fluid: They have all a remarkable attraction for water: They imbibe the humidity of the air with rapidity and the generation of heat. Although heat be produced by their union with water, yet when mixed with ice in a certain manner, they generate a prodigious degree of cold. Acids change the purple and blue colours of vegetables to a red: they resist fermentation; and lastly, they impress that peculiar sensation on the tongue called sourness, and which their name imports. But it is to be observed, that they are all highly corrosive, insomuch as not to be safely touched, unless largely diluted with water, or united with such substances as obtund or suppress their acidity. Mixed hastily with vinous spirits, they raise a violent ebullition and heat, accompanied with a copious discharge of noxious fumes: a part of the acid unites unites intimately with the vinous spirit into a new compound, void of acidity, called dulcified spirit. It is observable, that the marine acid is much less disposed to this union with spirit of wine than either of the other two; nevertheless, many of the compound salts resulting from the combination of earthy and metallic bodies with this acid, are soluble in that spirit, while those with the other acids are not. All these acids effervesc strongly with alkaline salts both fixed and volatile, and form with them neutral salts; that is, such as discover no marks either of an acid or alkaline quality.

The nitrous and marine acids are obtained in the form of a thin liquor; the acid part being blended with a large proportion of water, without which it would be diffused into an incalculable vapour: the vitriolic stands in need of so much less water for its condensation as to assume commonly an oily consistence (whence it is called oil of vitriol), and in some circumstances even a solid one. Alkaline salts, and the soluble earths and metals, absorb from the acid liquors only the pure acid part: so that the water may now be evaporated by heat, and the compound salt left in a dry form.

From the coalition of the different acids with the three different alkalis, and with the several soluble earths and metallic bodies, result a variety of saline compounds; the principal of which shall be particularized in the sequel of this article.

The vitriolic acid, in its concentrated liquid state, is much more ponderous than the other two; it emits no visible vapour in the heat of the atmosphere, but imbibes moisture which increases its weight: the nitrous and marine emit copious corrosive fumes, the nitrous yellowish red, and the marine white ones. If bottles containing the three acids be stopp'd with cork, the cork is found in a little time tinged black with the vitriolic, corroded into a yellow substance by the nitrous, and into a whitish one by the marine.

It is above laid down as a character of one of the classes of earths, that the vitriolic acid precipitates them when they are previously dissolved in any other acid: it is obvious, that on the same principle this particular acid may be distinguished from all others. This character serves not only for the acid in its pure state, but likewise for all its combinations that are soluble in water. If a solution of any compound salt, whose acid is the vitriolic, be added to a solution of chalk in any other acid, the vitriolic acid will part from the substance with which it was before combined, and join itself to the chalk, forming therewith a compound; which, being no longer soluble in the liquor, renders the whole milky for a time, and then gradually subsides.

This acid may be distinguished also, in compound salts, by another criterion not less strongly marked: If any salt containing it be mixed with powdered charcoal, and the mixture exposed in a close vessel to a moderately strong fire, the acid will unite with the directly inflammable part of the charcoal, and compose therewith a genuine sulphur. Common brimstone is no other than a combination of the vitriolic acid with a small proportion of inflammable matter. With any kind of inflammable matter which is not volatile in close vessels, as the coal of vegetables, of animals, or of bitumens, this acid composes always the same identical sulphur.

The nitrous acid also, with whatever kind of body it be combined, is both distinguished and extricated by means of any inflammable substance being brought to a state of ignition with it. If the subject be mixed with a little powdered charcoal and made red hot, a deflagration or fulmination ensues, that is, a bright flame with a hissing noise; and the inflammable matter and the acid being thus consumed or dissipated together, there remains only the substance which was before combined with the acid, and the small quantity of ashes afforded by the coal.

These properties of the nitrous acid deflagrating with inflammable substances, and of the vitriolic forming sulphur with them, serve not only as criteria of the respective acids in the various forms and disguises, but likewise for discovering inflammable matter in bodies, when its quantity is too small to be sensible on other trials.

All these acids will be more particularly examined when we come to treat of each of them apart. There are, however, a few other mineral acids which are of importance to be known: there are, aqua regia; acid of borax; sparry acid; and, lastly, fixed air, which has of late been called aerial acid, or acid of chalk.

Aqua regia has been generally prepared by a mixture of certain proportions of the nitrous and muriatic acids. It is of little avail in pharmacy whether we consider it as a distinct acid, or only as a modification of the muriatic. It has been found, that the muriatic acid when distilled with manganese (a peculiar fossil substance, showing a remarkable attraction to phlogiston), suffers a change which renders it capable of dissolving gold and platinum. Whether this change be produced by the acid acquiring a redundancy of pure air, or by its being deprived of phlogiston, it is not our business to decide. This experiment, however, renders it probable, that the nitrous acid in the common aqua regia is only subfervent to accomplishing the same change in the muriatic acid which is produced by distilling that acid with manganese.

As aqua regia has been only used in the nicer operations in chemistry, and in the art of assaying, we think it unnecessary to say more of it in this place.

The acid of borax, or sedative salt of Homberg, may be extracted from borax, a neutral salt, whose base is mineral alkali. It has also been found native in the waters of several lakes in Tuscany. It is a light, crystallized, concrete salt; its taste is feebly acid; it is difficultly soluble in water; but the solution changes blue vegetable colours to a red. With vitreous earths it fuses into a white glass; it unites with the other alkalis, with magnesia, and with quicklime. The salts resulting from these combinations are very imperfectly known. The salt has been called sedative, from its supposed virtues as an anodyne and refrigerant remedy; but modern physicians have very little faith in this once celebrated drug.

The sparry acid is so called from its being extracted from a fossil called sparry fluor, or vitreous spar. It is not yet determined whether it be a distinct acid; and as it has not yet been employed for any purpose in pharmacy, we think it would be improper to attempt any farther account of it here.

Besides Besides the acids above-mentioned, there have also been discovered acids seemingly of a particular nature, in amber, in arsenic, and in black-lead; but as these have not hitherto been applied to any use in pharmacy, they cannot properly have a place in this article.

We now come to the last, but perhaps the most generally diffused, acid in nature: this is the aerial acid, or Fixed Air.

In our pharmaceutical history of this body, we shall only make use of the two names fixed air and aerial acid, being those most generally used, and which in our opinion are most applicable to our own subject. Fixed air is a permanently elastic fluid, being only fixed when in a state of combination with calcareous earth or other substances from which it may be extricated. It has received many different names, according to the substances from which it is disengaged, and to the different opinions concerning its nature: it is the gas silvaticum of Helmot, the fixed air of Dr Black, the acid of chalk, calcareous gas, mephitic gas, mephitic acid, and aerial acid, of many modern chemists. In accommodating our account of it to the purposes of pharmacy, it is most convenient to consider it as an acid. The aerial acid may be extricated by heat, or by other acids, from all calcareous earths; that is, from all those earths which by calcination are converted into quicklime; such as chalk, marble, limestone, sea-shells, &c. It is likewise extricated from mild, fixed, and volatile alkalis, and from magnesia alba. Thus, if the vitriolic, or almost any other acid, be added to a quantity of calcareous earth or mild alkali, a brisk effervescence immediately ensues; the fixed air, or aerial acid, is discharged in bubbles; and the other acid takes its place. If this process be conducted with an apparatus to be afterwards described, the aerial acid, now separated from the calcareous earth, may be received and preserved in close vessels. When thus disengaged, it assumes its real character, viz. that of a permanently elastic fluid. Fixed air is also separated in great quantity during the vinous fermentation of vegetable matters. When a calcareous earth is deprived of this acid by heat, it is converted into the caustic substance quicklime. When alkalis, fixed or volatile, are deprived by any means of their aerial acid, they are rendered much more caustic, incapable of crystallization, or of effervescing with other acids. They are also in this deaerated state much more powerful in dissolving other bodies. By recombining this acid with quicklime, calcined magnesia, or alkali, any of which had been deprived of it, these substances again assume their former weight and properties. These bodies, then, when combined with aerial acid, are called mild; as mild calcareous earths, mild alkali, &c.; and when deprived of this acid they are called caustic; as caustic calcareous earths, caustic alkali, &c.: but as magnesia is not rendered caustic by calcination, there would perhaps be less danger in calling them aerated and deaerated. The aerial acid is more disposed to unite with caustic calcareous earth (quicklime) than with any other substance; next to that, its attraction is for fixed alkali, then for magnesia, and lastly for volatile alkali. We shall afterwards find that these relative powers of the different substances to unite with this acid, lay the foundation of many important processes in pharmacy.

When we pour a small quantity of the aerial acid into lime-water, the liquor instantly assumes a white colour, and the lime gradually precipitates, leaving the water clear and tasteless: the lime in this experiment has absorbed the acid, and has therefore become mild or aerated earth. The aerial acid is capable of being absorbed by water, and the water thus impregnated precipitates lime in lime-water; but if a certain larger quantity of this impregnated water be added, the lime is redissolved, and the liquor recovers its transparency. Water impregnated with aerial acid is capable of dissolving iron; and in this way are formed native and artificial chalybeate waters. Zinc is also soluble in the same liquor. This acid is easily expelled from the water by removing the pressure of the atmosphere, by boiling, and even by time alone, if the vessel be not kept close shut. Fixed air extinguishes flame, vegetable and animal life, and ought therefore to be cautiously managed; like other acids it changes the blue colours of vegetables to a red, and communicates an acidulous taste to the water impregnated with it. The attraction of the aerial acid, even to quicklime, is but feeble; as we know of no other acids whatever that are not able to disengage it.

From these several facts it will appear obvious, that mild or effervescent alkalis, whether fixed or volatile, are really neutral salts, compounded of the aerial acid and pure alkali: like other acids, it unites with these bodies, diminishes their causticity, and effects their crystallization. In speaking, therefore, of pure alkali, we ought to confine ourselves to those in the caustic or deaerated state; or, in other words, to those which are deprived of their fixed air or aerial acid, with which they formed a compound salt. Many other properties of this acid might be mentioned, but we have now noticed all those which we thought were concerned in the business of pharmacy. We shall have occasion to recur to the subject when we come to the preparation of several compound drugs.

Let us next take a view of what passes in the combinations of acids with different substances.

If a fixed alkaline salt be united with a vegetable acid, as vinegar, and formed into a neutral salt, on adding to this compound some marine acid, the acetous acid will be disengaged, so as to exhale totally in a moderate heat, leaving the marine in possession of the alkali: the addition of the nitrous will in like manner dispel the marine, which now arises in its proper white fumes, though without such an addition it could not be extricated from the alkali by any degree of heat: on the addition of the vitriolic acid, the nitrous gives way in its turn, exhaling in red fumes, and leaving only the vitriolic acid and the alkali united together.

Again, if any metallic body be dissolved in an acid, the addition of any earthy body that is dissoluble in that acid will precipitate the metal: a volatile alkaline salt will in like manner precipitate the earth: and a fixed alkali will dissolve the volatile: which last being readily exhaled by heat, the remaining salt will be the same as if the acid and fixed alkali had been joined together at first, without the intervention of any of the other bodies. The power in bodies on which these various transpositions and combinations depend, is called by the chemists affinity or elective attraction; a term, like the Newtonian attraction, designed to express not the cause, but the effect. When an acid spontaneously quits a metal to unite with an alkali, they say it has a greater affinity or attraction to the alkali than to the metal: and when, on the contrary, they say it has a greater affinity to fixed alkali than to the volatile, they mean only that it will unite with the fixed in preference to the volatile; and that if previously united with a volatile alkali, it will forsake this for a fixed one.

The doctrine of the affinities of bodies is of a very extensive use in chemical pharmacy: many of the officinal processes, as we shall see hereafter, are founded on it: several of the preparations turn out very different from what would be expected by a person unacquainted with these properties of bodies; and several of them, if, from an error in the process, or other causes, they prove unfit for the use intended, may be rendered applicable to other purposes, by such transpositions of their component parts as are pointed out by the knowledge of their affinities.

We shall therefore subjoin a table of the principal affinities observed in pharmaceutical operations, formed from that of the famous Bergman. See other tables for more general purposes in the article Chemistry.

The table is to be thus understood. The substance printed in capitals, on the top of each series, has the greatest affinity with that immediately under it, a less affinity with the next, and so on to the end of the series; that is, if any of the remote bodies has been combined with the top one, the addition of any of the intermediate bodies will disunite them; the intermediate body uniting with the uppermost body of the series, and throwing out the remote one. Thus, in the first series of the affinities of the vitriolic acid, a fixed alkali being placed between the acid and iron, it is to be concluded, that wherever vitriolic acid and iron are mixed together, the addition of any fixed alkaline salt will unite with the acid, and occasion the iron to be separated. Where several substances are expressed in one series, it is to be understood, that any of those bodies which are nearer to the uppermost, will in like manner disengage from it any of those which are more remote. ### Table of Single Attractions

#### By Water

| Vitriolic Acid | Nitrous Acid | Marine Acid | Aqua Regia | Acid of Borax | Acid of Sugar | Acid of Tarter | Acid of Sorrel | Acid or Lemon | |---------------|--------------|-------------|------------|---------------|--------------|---------------|----------------|---------------| | Terra ponderosa | Vegetable alkali, Foffil alkali, Terra ponderofoa, Lime, Magnesia, Volatile alkali, Clay | Lime, Terra ponderofoa, Vegetable alkali, Foffil alkali, Lime, Magnesia, Volatile alkali, Clay | Lime, Terra ponderofoa, Vegetable alkali, Foffil alkali, Lime, Magnesia, Volatile alkali, Clay | Lime, Terra ponderofoa, Vegetable alkali, Foffil alkali, Lime, Magnesia, Volatile alkali, Clay | Lime, Terra ponderofoa, Vegetable alkali, Foffil alkali, Lime, Magnesia, Volatile alkali, Clay | Lime, Terra ponderofoa, Vegetable alkali, Foffil alkali, Lime, Magnesia, Volatile alkali, Clay | Lime, Terra ponderofoa, Vegetable alkali, Foffil alkali, Lime, Magnesia, Volatile alkali, Clay | Lime, Terra ponderofoa, Vegetable alkali, Foffil alkali, Lime, Magnesia, Volatile alkali, Clay |

#### By Fire

| Vegetable alkali, Foffil alkali, Terra ponderofoa, Lime, Magnesia, Metals, Volatile alkali, Clay | Terra ponderofoa, Vegetable alkali, Foffil alkali, Lime, Magnesia, Metals, Volatile alkali, Clay | Terra ponderofoa, Vegetable alkali, Foffil alkali, Lime, Magnesia, Metals, Volatile alkali, Clay | Terra ponderofoa, Vegetable alkali, Foffil alkali, Lime, Magnesia, Metals, Volatile alkali, Clay | Terra ponderofoa, Vegetable alkali, Foffil alkali, Lime, Magnesia, Metals, Volatile alkali, Clay | Terra ponderofoa, Vegetable alkali, Foffil alkali, Lime, Magnesia, Metals, Volatile alkali, Clay | Terra ponderofoa, Vegetable alkali, Foffil alkali, Lime, Magnesia, Metals, Volatile alkali, Clay | Terra ponderofoa, Vegetable alkali, Foffil alkali, Lime, Magnesia, Metals, Volatile alkali, Clay | Terra ponderofoa, Vegetable alkali, Foffil alkali, Lime, Magnesia, Metals, Volatile alkali, Clay |

---

**Table** | Acetous Acid | Acid of Phosphorus | Vegetable Alkali | Fossil Alkali | Volatile Alkali | Terra ponderofa | Lime, Vegetable alkali, Fossil alkali, Volatile alkali, Lime, Magnesia, Clay, Zinc, Iron, Lead, Tin, Copper, Antimony, Arsenic, Mercury, Silver, Gold, Water, Alcohol | |-------------|-------------------|-----------------|--------------|----------------|----------------|--------------------------------------------------| | Terra ponderofa | Vitriolic acid, Nitrous acid, Marine acid, Phosphoric acid, Acid of fuggy, Acid of tartar, Acid of forrel, Acid of lemon, Acid of benzoin, Acetona acid, Acid of borax, Aerial acid, Water, Unctuous oils, Sulphur, Metals. | | Vegetable alkali | Vitriolic acid, Nitrous acid, Marine acid, Phosphoric acid, Acid of fuggy, Acid of tartar, Acid of forrel, Acid of lemon, Acid of benzoin, Acetona acid, Acid of borax, Aerial acid, Water, Unctuous oils, Sulphur, Metals. | | Fossil alkali | Vitriolic acid, Nitrous acid, Marine acid, Phosphoric acid, Acid of fuggy, Acid of tartar, Acid of forrel, Acid of lemon, Acid of benzoin, Acetona acid, Acid of borax, Aerial acid, Water, Unctuous oils, Sulphur, Metals. | | Volatile alkali | Vitriolic acid, Nitrous acid, Marine acid, Phosphoric acid, Acid of fuggy, Acid of tartar, Acid of forrel, Acid of lemon, Acid of benzoin, Acetona acid, Acid of borax, Aerial acid, Water, Unctuous oils, Sulphur, Metals. | | Terra ponderofa | Vitriolic acid, Nitrous acid, Marine acid, Phosphoric acid, Acid of fuggy, Acid of tartar, Acid of forrel, Acid of lemon, Acid of benzoin, Acetona acid, Acid of borax, Aerial acid, Water, Unctuous oils, Sulphur, Metals. | | Lime, Vegetable alkali, Fossil alkali, Volatile alkali, Lime, Magnesia, Clay, Zinc, Iron, Lead, Tin, Copper, Antimony, Arsenic, Mercury, Silver, Gold, Water, Alcohol. |

| By Fire | | |---------|---| | Terra ponderofa | Vitriolic acid, Nitrous acid, Marine acid, Phosphoric acid, Acid of fuggy, Acid of tartar, Acid of forrel, Acid of lemon, Acid of benzoin, Acetona acid, Acid of borax, Aerial acid, Water, Unctuous oils, Sulphur, Metals. | | Vegetable alkali | Vitriolic acid, Nitrous acid, Marine acid, Phosphoric acid, Acid of fuggy, Acid of tartar, Acid of forrel, Acid of lemon, Acid of benzoin, Acetona acid, Acid of borax, Aerial acid, Water, Unctuous oils, Sulphur, Metals. | | Fossil alkali | Vitriolic acid, Nitrous acid, Marine acid, Phosphoric acid, Acid of fuggy, Acid of tartar, Acid of forrel, Acid of lemon, Acid of benzoin, Acetona acid, Acid of borax, Aerial acid, Water, Unctuous oils, Sulphur, Metals. | | Volatile alkali | Vitriolic acid, Nitrous acid, Marine acid, Phosphoric acid, Acid of fuggy, Acid of tartar, Acid of forrel, Acid of lemon, Acid of benzoin, Acetona acid, Acid of borax, Aerial acid, Water, Unctuous oils, Sulphur, Metals. | | Terra ponderofa | Vitriolic acid, Nitrous acid, Marine acid, Phosphoric acid, Acid of fuggy, Acid of tartar, Acid of forrel, Acid of lemon, Acid of benzoin, Acetona acid, Acid of borax, Aerial acid, Water, Unctuous oils, Sulphur, Metals. | | Lime, Vegetable alkali, Fossil alkali, Volatile alkali, Lime, Magnesia, Clay, Zinc, Iron, Lead, Tin, Copper, Antimony, Arsenic, Mercury, Silver, Gold, Water, Alcohol. |

| Magnesia | | |----------|---| | Acid of fuggy, Phosphoric acid, Vitriolic acid, Nitrous acid, Marine acid, Phosphoric acid, Acid of fuggy, Acid of tartar, Acid of forrel, Acid of lemon, Acid of benzoin, Acetona acid, Acid of borax, Aerial acid, Water, Unctuous oils, Sulphur, Metals. | | Acid of fuggy, Phosphoric acid, Vitriolic acid, Nitrous acid, Marine acid, Phosphoric acid, Acid of fuggy, Acid of tartar, Acid of forrel, Acid of lemon, Acid of benzoin, Acetona acid, Acid of borax, Aerial acid, Water, Unctuous oils, Sulphur, Metals. | | Acid of fuggy, Phosphoric acid, Vitriolic acid, Nitrous acid, Marine acid, Phosphoric acid, Acid of fuggy, Acid of tartar, Acid of forrel, Acid of lemon, Acid of benzoin, Acetona acid, Acid of borax, Aerial acid, Water, Unctuous oils, Sulphur, Metals. | | Acid of fuggy, Phosphoric acid, Vitriolic acid, Nitrous acid, Marine acid, Phosphoric acid, Acid of fuggy, Acid of tartar, Acid of forrel, Acid of lemon, Acid of benzoin, Acetona acid, Acid of borax, Aerial acid, Water, Unctuous oils, Sulphur, Metals. | | Acid of fuggy, Phosphoric acid, Vitriolic acid, Nitrous acid, Marine acid, Phosphoric acid, Acid of fuggy, Acid of tartar, Acid of forrel, Acid of lemon, Acid of benzoin, Acetona acid, Acid of borax, Aerial acid, Water, Unctuous oils, Sulphur, Metals. | | Lime, Vegetable alkali, Fossil alkali, Volatile alkali, Lime, Magnesia, Clay, Zinc, Iron, Lead, Tin, Copper, Antimony, Arsenic, Mercury, Silver, Gold, Water, Alcohol. |

| Lime | | |------|---| | Acid of fuggy, Phosphoric acid, Vitriolic acid, Nitrous acid, Marine acid, Phosphoric acid, Acid of fuggy, Acid of tartar, Acid of forrel, Acid of lemon, Acid of benzoin, Acetona acid, Acid of borax, Aerial acid, Water, Unctuous oils, Sulphur, Metals. | | Acid of fuggy, Phosphoric acid, Vitriolic acid, Nitrous acid, Marine acid, Phosphoric acid, Acid of fuggy, Acid of tartar, Acid of forrel, Acid of lemon, Acid of benzoin, Acetona acid, Acid of borax, Aerial acid, Water, Unctuous oils, Sulphur, Metals. | | Acid of fuggy, Phosphoric acid, Vitriolic acid, Nitrous acid, Marine acid, Phosphoric acid, Acid of fuggy, Acid of tartar, Acid of forrel, Acid of lemon, Acid of benzoin, Acetona acid, Acid of borax, Aerial acid, Water, Unctuous oils, Sulphur, Metals. | | Acid of fuggy, Phosphoric acid, Vitriolic acid, Nitrous acid, Marine acid, Phosphoric acid, Acid of fuggy, Acid of tartar, Acid of forrel, Acid of lemon, Acid of benzoin, Acetona acid, Acid of borax, Aerial acid, Water, Unctuous oils, Sulphur, Metals. | | Acid of fuggy, Phosphoric acid, Vitriolic acid, Nitrous acid, Marine acid, Phosphoric acid, Acid of fuggy, Acid of tartar, Acid of forrel, Acid of lemon, Acid of benzoin, Acetona acid, Acid of borax, Aerial acid, Water, Unctuous oils, Sulphur, Metals. | | Lime, Vegetable alkali, Fossil alkali, Volatile alkali, Lime, Magnesia, Clay, Zinc, Iron, Lead, Tin, Copper, Antimony, Arsenic, Mercury, Silver, Gold, Water, Alcohol. |

| Sulphur | | |---------|---| | Acid of fuggy, Phosphoric acid, Vitriolic acid, Nitrous acid, Marine acid, Phosphoric acid, Acid of fuggy, Acid of tartar, Acid of forrel, Acid of lemon, Acid of benzoin, Acetona acid, Acid of borax, Aerial acid, Water, Unctuous oils, Sulphur, Metals. | | Acid of fuggy, Phosphoric acid, Vitriolic acid, Nitrous acid, Marine acid, Phosphoric acid, Acid of fuggy, Acid of tartar, Acid of forrel, Acid of lemon, Acid of benzoin, Acetona acid, Acid of borax, Aerial acid, Water, Unctuous oils, Sulphur, Metals. | | Acid of fuggy, Phosphoric acid, Vitriolic acid, Nitrous acid, Marine acid, Phosphoric acid, Acid of fuggy, Acid of tartar, Acid of forrel, Acid of lemon, Acid of benzoin, Acetona acid, Acid of borax, Aerial acid, Water, Unctuous oils, Sulphur, Metals. | | Acid of fuggy, Phosphoric acid, Vitriolic acid, Nitrous acid, Marine acid, Phosphoric acid, Acid of fuggy, Acid of tartar, Acid of forrel, Acid of lemon, Acid of benzoin, Acetona acid, Acid of borax, Aerial acid, Water, Unctuous oils, Sulphur, Metals. | | Acid of fuggy, Phosphoric acid, Vitriolic acid, Nitrous acid, Marine acid, Phosphoric acid, Acid of fuggy, Acid of tartar, Acid of forrel, Acid of lemon, Acid of benzoin, Acetona acid, Acid of borax, Aerial acid, Water, Unctuous oils, Sulphur, Metals. | | Lime, Vegetable alkali, Fossil alkali, Volatile alkali, Lime, Magnesia, Clay, Zinc, Iron, Lead, Tin, Copper, Antimony, Arsenic, Mercury, Silver, Gold, Water, Alcohol. |

| Lead | | |------|---| | Acid of fuggy, Phosphoric acid, Vitriolic acid, Nitrous acid, Marine acid, Phosphoric acid, Acid of fuggy, Acid of tartar, Acid of forrel, Acid of lemon, Acid of benzoin, Acetona acid, Acid of borax, Aerial acid, Water, Unctuous oils, Sulphur, Metals. | | Acid of fuggy, Phosphoric acid, Vitriolic acid, Nitrous acid, Marine acid, Phosphoric acid, Acid of fuggy, Acid of tartar, Acid of forrel, Acid of lemon, Acid of benzoin, Acetona acid, Acid of borax, Aerial acid, Water, Unctuous oils, Sulphur, Metals. | | Acid of fuggy, Phosphoric acid, Vitriolic acid, Nitrous acid, Marine acid, Phosphoric acid, Acid of fuggy, Acid of tartar, Acid of forrel, Acid of lemon, Acid of benzoin, Acetona acid, Acid of borax, Aerial acid, Water, Unctuous oils, Sulphur, Metals. | | Acid of fuggy, Phosphoric acid, Vitriolic acid, Nitrous acid, Marine acid, Phosphoric acid, Acid of fuggy, Acid of tartar, Acid of forrel, Acid of lemon, Acid of benzoin, Acetona acid, Acid of borax, Aerial acid, Water, Unctuous oils, Sulphur, Metals. | | Acid of fuggy, Phosphoric acid, Vitriolic acid, Nitrous acid, Marine acid, Phosphoric acid, Acid of fuggy, Acid of tartar, Acid of forrel, Acid of lemon, Acid of benzoin, Acetona acid, Acid of borax, Aerial acid, Water, Unctuous oils, Sulphur, Metals. | | Lime, Vegetable alkali, Fossil alkali, Volatile alkali, Lime, Magnesia, Clay, Zinc, Iron, Lead, Tin, Copper, Antimony, Arsenic, Mercury, Silver, Gold, Water, Alcohol. | | Clay | Water | Sulphur | Hepar sulphuris | Alcohol | Ether | Essential oils | Expresssed oils | Gold | |------|-------|---------|----------------|---------|-------|---------------|----------------|------| | Vitriolic acid | Vegetable alkali | Lead | Tin | Gold | Silver | Mercury | Arsenic | Copper | Tin | Iron | Lead | Iron | Terra pouderofa | Alcohol | Water | | Nitrous acid | Fossil alkali | Volatile alkali | Alcohol | Ether | Vitriolic acid | Vitriolated tartar | Acid of tartrate | Antimony | Fixed alkali | Sulphur | Hepar fulphuris | Sulphur | | Marine acid | Acid of sugar | Acid of forrel | Acid of tartar | Acid of lemon | Acid of phlophorus | Acid of benzoic | Acetous acid | Acid of borax | Aerial acid | Vegetable alkali | Volatile alkali | Lime | Magnesia | Undecuous oils | Essential oils | Alcohol |

| By Fire | Fixed alkali | Iron | Copper | Tin | Lead | Silver | Antimony | Mercury | Arsenic | |---------|--------------|------|--------|----|------|--------|----------|---------|--------| | Phosphoric acid | Acid of borax | Vitriolic acid | Nitrous acid | Marine acid | Fixed alkali | Sulphur | Lead | | Silver | Mercury | Lead | Iron | Copper | Tin | Arsenic | Zinc | Antimony | |--------|---------|------|------|--------|-----|---------|------|----------| | Marine acid, Acid of fugar, Vitriolic acid, Phosphoric acid, Nitrous acid, Acid of tartar, Acid of lemon, Acetone acid, Acid of borax, Aerial acid, Fixed alkali, Volatile alkali, Exprefed oils. | Marine acid, Acid of fugar, Vitriolic acid, Phosphoric acid, Nitrous acid, Acid of tartar, Acid of lemon, Acetone acid, Acid of borax, Aerial acid, Fixed alkali, Volatile alkali, Exprefed oils. | Marine acid, Acid of fugar, Vitriolic acid, Phosphoric acid, Nitrous acid, Acid of tartar, Acid of lemon, Acetone acid, Acid of borax, Aerial acid, Fixed alkali, Volatile alkali, Exprefed oils. | Marine acid, Acid of fugar, Vitriolic acid, Phosphoric acid, Nitrous acid, Acid of tartar, Acid of lemon, Acetone acid, Acid of borax, Aerial acid, Fixed alkali, Volatile alkali, Exprefed oils. | Marine acid, Acid of fugar, Vitriolic acid, Phosphoric acid, Nitrous acid, Acid of tartar, Acid of lemon, Acetone acid, Acid of borax, Aerial acid, Fixed alkali, Volatile alkali, Exprefed oils. | Marine acid, Acid of fugar, Vitriolic acid, Phosphoric acid, Nitrous acid, Acid of tartar, Acid of lemon, Acetone acid, Acid of borax, Aerial acid, Fixed alkali, Volatile alkali, Exprefed oils. | Marine acid, Acid of fugar, Vitriolic acid, Phosphoric acid, Nitrous acid, Acid of tartar, Acid of lemon, Acetone acid, Acid of borax, Aerial acid, Fixed alkali, Volatile alkali, Exprefed oils. | Marine acid, Acid of fugar, Vitriolic acid, Phosphoric acid, Nitrous acid, Acid of tartar, Acid of lemon, Acetone acid, Acid of borax, Aerial acid, Fixed alkali, Volatile alkali, Exprefed oils. |

| By Fire | Zine | Mercury | Copper, Antimony, Gold, Silver, Lead, Tin, Antimony, Lead, Mercury, Iron, Arsenic, Hepar fulphuris, Sulphur. | Copper, Antimony, Gold, Silver, Lead, Tin, Antimony, Lead, Mercury, Iron, Arsenic, Hepar fulphuris, Sulphur. | Copper, Antimony, Gold, Silver, Lead, Tin, Antimony, Lead, Mercury, Iron, Arsenic, Hepar fulphuris, Sulphur. | Copper, Antimony, Gold, Silver, Lead, Tin, Antimony, Lead, Mercury, Iron, Arsenic, Hepar fulphuris, Sulphur. | Copper, Antimony, Gold, Silver, Lead, Tin, Antimony, Lead, Mercury, Iron, Arsenic, Hepar fulphuris, Sulphur. | Copper, Antimony, Gold, Silver, Lead, Tin, Antimony, Lead, Mercury, Iron, Arsenic, Hepar fulphuris, Sulphur. |

| Lead, Copper, Mercury, Tin, Gold, Antimony, Arsenic, Iron, Zinc, Elepar fulphuris. | Gold, Silver, Copper, Mercury, Tin, Antimony, Arsenic, Iron, Zinc, Elepar fulphuris. | Gold, Silver, Copper, Mercury, Tin, Antimony, Arsenic, Iron, Zinc, Elepar fulphuris. | Gold, Silver, Copper, Mercury, Tin, Antimony, Arsenic, Iron, Zinc, Elepar fulphuris. | Gold, Silver, Copper, Mercury, Tin, Antimony, Arsenic, Iron, Zinc, Elepar fulphuris. | Gold, Silver, Copper, Mercury, Tin, Antimony, Arsenic, Iron, Zinc, Elepar fulphuris. | Gold, Silver, Copper, Mercury, Tin, Antimony, Arsenic, Iron, Zinc, Elepar fulphuris. | Gold, Silver, Copper, Mercury, Tin, Antimony, Arsenic, Iron, Zinc, Elepar fulphuris. | CASES OF DOUBLE ELECTIVE ATTRACTIONS.

By WATER.

1. Epsom salt with Mild vegetable alkali, 2. Vitriolic ammoniac with Mild mineral alkali, 3. Vitriolated tartar with Nitrous felenite, 4. Vitriolated tartar with Mercurial nitre, 5. Saltpetre with Luna cornea, 6. Vitriolated tartar with Luna cornea, 7. Regenerated tartar with Mercurial nitre,

By HEAT.

1. Vitriolic ammoniac with Common salt, 2. Vitriolic ammoniac with Regenerated tartar, 3. Vitriol of mercury with Common salt, 4. Crude antimony with Corrosive sublimate,

CHAP. II. Of the Pharmaceutical Apparatus.

One of the principal parts of the pharmaceutical apparatus consists in contrivances for containing and applying fire, and for directing and regulating its power. Of these contrivances called furnaces, there are different kinds, according to the conveniency of the place, and the particular purposes they are intended to answer. We shall here endeavour to give a general idea of their structure, and of the principles on which they are built; and for particulars refer the reader to Furnace; and Chemistry, page 450.

The most simple furnace is the common flue, otherwise called the furnace for open fire. This is usually open fire made of an iron hoop, five or six inches deep; with a grate or some iron bars across the bottom, for supporting the fuel. It either stands upon feet, so as to be moveable from place to place; or is fixed in brick-work. In this last case, a cavity is left under the grate, for receiving the ashes that drop through it; and an aperture or door, in the forefront of this ash-pit, serves both for allowing the ashes to be occasionally raked out, and for admitting air to pass up through the fuel. This furnace is designed for such operations as require only a moderate heat; as infusion, decoction, and the evaporation of liquids.

A deeper hoop or body, cylindrical, parallelopipedal, widening upwards, elliptical, or of other figures; formed of, or lined with, such materials as are capable of sustaining a strong fire; with a grate and ash-pit beneath, as in the preceding; and communicating at the top with a perpendicular pipe, or chimney; makes a wind furnace.

The greater the perpendicular height of the chimney, the greater will be the draught of air through the furnace, and the more intensely will the fire burn; provided the width of the chimney is sufficient to allow a free passage to all the air that the furnace can receive through the grate; for which purpose, the area of the circular aperture of the chimney should be nearly equal to the area of the interfaces of the grate.

Hence, where the chimney consists of moveable pipes, made to fit upon each other at the ends, so that the length can be occasionally increased or diminished, the vehemence of the fire will be increased or diminished in the same proportion.

In furnaces whose chimney is fixed, the same advantage may be procured on another principle. As the intensity of the fire depends wholly upon the quantity of air successively passing through and animating the burning fuel, it is obvious, that the most vehement fire may be suppressed or refrained at pleasure, by closing more or less either the ash-pit door by which the air is admitted, or the chimney by which it passes off; and that the fire may be more or less raised again, by more or less opening those passages. A moveable plate, or register, in any convenient part of the chimney, affords commodious means of varying the width of the passage, and consequently of regulating the heat. This is most conveniently accomplished by keeping the ash-pit door entirely shut, and regulating the heat by a range of holes in a damping plate; each hole is provided with a proper pin, whereby we may shut it at pleasure. These holes may be made to bear a certain proportion to each other; the smallest being considered as one, the next to it in size must have twice the opening, the next to that double of the second, &c.; and so on to the number of seven or eight; and by combining these holes variously together, we can admit any quantity of air from 1 to 128; as 1, 2, 4, 8, 16, 32, 64, 128. See Furnace, p. 507.

There are two general kinds of these wind-furnaces; one, with the chimney on the top, over the middle of the furnace; the other with the chimney on one side, and the mouth clear. In the first, either the upper part of the furnace is contracted to such an aperture, that the chimney may fit upon it; or it is covered with an arched dome, or with a flat plate, having a like aperture in the middle. As in this disposition of the chimney, the inside of the furnace cannot be come at from above, a door is made in the side, a little above the grate, for supplying the fuel, inspecting the matter in the fire, &c.

For performing fusions in this furnace, the crucible, or melting vessel, is placed immediately among the fuel, with a slip of brick, or some other like support, between it and the grate, to keep the cold air, which enters underneath, from striking on its bottom.

When designed as a reverberatory, that is for distillation in long-necked coated glass retorts, two iron bars are placed across, above the fire, for supporting the vessel, whose neck comes out at an aperture made for that purpose in the side. This aperture should be made in the side opposite to the door above-mentioned; or at least so remote from it, that the receiver, fitted on the neck of the distilling vessel without the furnace, may not lie in the operator's way when he wants to stir the fire or throw in fresh fuel.

The other kind of wind-furnace communicates, by an aperture in its back part near the top, either with an upright pipe of its own, or with the chimney of the room; in which last case, all other passages into the chimney must be closed. Here the mouth of the furnace serves for a door, which may be occasionally covered with a plate or tile. Of this kind is the furnace most commonly used for fusion in a crucible.

This last construction, by leaving the mouth of the furnace clear, affords the convenience of letting into it a boiling or evaporating pan, a copper still, an iron pot, for distilling hartshorn, an iron land-pot, or other like vessels, of such a size that they may be supported on the furnace by their rims. The mouth being thus occupied by the vessels, a door must be made in the side for supplying and stirring the fuel.

When a furnace of this kind is designed only for a sand bath, it is most commodious to have the sand placed on a long iron plate, furnished with a ledge of freestone or brick-work at each side. The mouth of the furnace is to be closely covered by one end of this plate; and the canal by which the furnace communicates with its chimney, is to be lengthened and carried along under the plate, the plate forming the upper side of the canal. In this kind of sand-bath, digestions, &c., requiring different degrees of heat, may be carried on at once; for the heat decreases gradually from the end over the furnace to the other.

When large vessels, as stills and iron pots for distilling hartshorn and aquafortis, are fixed in furnaces, a considerable part of the bottom of the vessel is commonly made to rest upon solid brick-work.

The large still, whose bottom is narrow in proportion to its height, and whose weight, when charged with liquor, requires great part of it to be thus supported, exposes but a small surface to the action of the fire underneath. To make up for this disadvantage, the heat, which rises at the further end of a long narrow grate, is conveyed all round the sides of the vessel by a spiral canal, which communicates at top with a common chimney.

The pots for distilling hartshorn and aquafortis in the larger way, have part of their great weight borne up by three strong pins or trunions at equal distances round the pot towards the middle reaching into a brick-work; so that less support being necessary underneath, a greater surface of the wide bottom lies exposed to the immediate action of the fire.

If a furnace, communicating with its chimney by a lateral canal, as in the sand-furnace above-mentioned, be carried to a considerable height above the part where this canal enters it, and if it be filled with fuel to the top, and closely covered, the fuel will burn no higher than up to the upper side of the canal through which the air passes off; and in proportion as this lower part of the fuel consumes, it will be supplied by that above, which falls down in its place. Hence in this furnace, called an athanor, a constant heat may be kept up for a considerable length of time without attendance.

The tower of the athanor, or that part which receives the fuel, is commonly made to widen a little downwards, that the coals may fall the more freely; but not so much as that the part on tire at bottom may be too strongly pressed. A small aperture is made opposite to the canal or flue, or a number of openings according to the size of the furnace and the degree of heat required, for supplying the air, which is more conveniently admitted in this manner than through the grate, as the interstices of the grate are in time choked up by the ashes.

This furnace is designed only for heating bodies exterior to it. Its canal or flue, as in the sand-furnace already described, passes under a sand-bath or water-bath; at the farther end of which it rises perpendicularly to such a height, as may occasion a sufficient draught of air through the fire.

The flue may be so wide as to correspond to the whole height of the fire-place. A register or sliding plate, placed between the flue and the furnace, enable us to increase or diminish this height, and consequently the quantity of fire, at pleasure. If the space beneath the flue be inclosed to the ground, the heat in this cavity will be considerable enough to be applicable to some useful purposes.

With regard to the materials of furnaces, the fixed ones are built of bricks, cemented together by some materials of good loam or clay. Any kind of loam or clayey composition that is of a proper degree of tenacity, which, when made into a patte with water and well-worked, does not stick to the fingers, and which, when thoroughly dried, neither cracks nor melts in a vehement fire, is fit for use. The purer and more tenacious clays require to have their tenacity lessened by an admixture of sand, or rather of the same kind of clay burnt and grossly powdered.

Smaller portable furnaces are made of strong iron or copper plates, lined, to the thickness of an inch or more, with the same kind of clayey composition; which for this use may be beaten with some horse-dung, chopped straw, or cut hair or tow.

Very commodious portable furnaces, for a business of moderate extent, may be formed of the larger kind of common black-lead melting-pots, by cutting a door at the bottom of the pot for the ash-pit, another above this for the fire-place, and introducing a circular iron grate of such a size as may rest between the two doors. For a more particular account of the method of preparing furnaces, see Furnace.

Baths.

Where a strong degree of heat is requisite, as in the fusion of metals, &c. the vessel containing the subject matter is placed among the burning fuel, or immediately over it; this is called operating in a naked fire. Where a smaller heat is sufficient, and the vessel employed is either of glass, or of the more tender kinds of earthen ware, the sand-bath or water-bath is used to defend the vessel from the immediate action of the fire, and to render the heat less fluctuating.

Both these baths have their peculiar advantages and inconveniences. In water, the heat is equal through every part of the fluid; whereas in sand it varies in different parts of one perpendicular line, decreasing from the bottom to the top. Water cannot be made to receive, or to transmit to vessels immersed in it, above a certain degree of heat, viz. that which is sufficient to make it boil; and hence it secures effectually against any danger of an excess of heat in those operations wherein the product would be injured by a heat greater than that of boiling water; but this advantage renders it useless for processes which require a greater heat, and for which land or other solid intermedia are necessarily employed. There is this convenience also in the sand-bath, that the heat may be readily diminished or increased about any particular vessel, by raising it higher out of the sand or sinking it deeper; that different subjects may be exposed to different degrees of heat from one fire; and that it keeps the vessels steady. The sand made choice of should be a large coarse grained kind, separated from the finer parts by washing, and from little stones by the sieve.

Coating of Glasses, Lutes.

Some processes require to be performed with glass vessels in a naked fire. For these purposes, vessels made of the thinnest glass should be chosen; for these bear the fire without cracking, much better than those which are thicker, and in appearance stronger.

All glasses, or other vessels that are apt to crack in the fire, must be cautiously heated, that is, heated by slow degrees; and when the process is finished, they should be slowly cooled, unless where the vessel is to be broken to get out the preparation, as in some sublimations; in this case it is more advisable to expose the hot glass suddenly to the cold air, which will soon occasion it to crack, than to endanger throwing down the sublimated matter among the feces by a blow.

As a defence from the violence of the fire, and to prevent the contact of cold air on supplying fresh fuel, &c. the glass is to be coated over, to the thickness of about half-a-crown, with Windsor loam, softened with water into a proper consistence, and heated up with some horse-dung, or with the other clayey compositions above mentioned.

These compositions serve also as a lute, for securing the junctures of the vessels in the distillation of the volatile salts and spirits of animals: for the distillation of acid spirits, the matter may be moistened with a solution of fixed alkaline salt instead of water. For most other purposes, a piece of wet bladder, or paste of flour and water, or of linseed meal (that is, the cake left after the expression of oil of linseed), are sufficient lutes.

Sometimes clay and chalk are mixed up into a paste, and spread upon slips of paper; and sometimes gum-arabic is used instead of the clay, and mixed up in the same manner.

Wet bladders contract so strongly by drying, that they not unfrequently break the vessels; and the fat lute of Mr Macquer, which is a composition of clay and chalk with oil, is too close for most operations. Where very elastic fumes are to be condensed, we are often obliged, even where the common lutes are employed, to leave or make an opening which may be occasionally stopped by a plug: by this means we give passage to a part of these vapours, which prevents the bursting of the vessels and facilitates the condensation of the rest. If we wish to collect incondensible vapours, we receive them into a jar inverted under a basin of water, or quicksilver, as is usually done in the analysis of vegetables by fire.

Besides these, there are also required some other kinds of lutes for joining vessels together in operations requiring a strong heat, and for lining furnaces; for which see Chemistry, n° 64, 605.

Vessels.

In this place, we shall only give the operator a few general cautions with regard to the matter of the vessels designed for containing the subject; and refer their description, to the account of the operations in which they are employed. See likewise Chemistry, n° 557, &c.

Metalline vessels possess the advantage of being able to bear sudden alterations of heat and cold, and of bearing very strong, so as to be capable of containing elastic fumes; but, except those made of gold or silver, vessels they are readily corroded by acids, even by the mild ones of the vegetable kingdom. Copper vessels are corroded also by alkaline liquors, and by some neutral ones, as solutions of sal ammoniac. It is observable, that vegetable acids do not act upon this metal by boiling, so much as by standing in the cold; for even lemon juice may be boiled in a clean copper vessel, without receiving from it any taste or ill quality; whereas, in the cold, it soon dissolves to much as to contract a pernicious taint. The tin, with which copper-vessels are usually lined, gives likewise a sensible impregnation to acid juices; and this impregnation also is probably not innocent, more especially as a quantity of lead is commonly mixed with the tin. From the want of transparency in these vessels, we are also deprived of the advantage of seeing the different changes during the operation.

The earthen vessels possess none of the desirable qualities for chemical operations, except that of sustaining very violent degrees of heat, without being melted or otherwise changed. These vessels are less liable to external cracks from sudden applications of heat and cold, when they are made with a certain proportion of sand, than with pure clay. Black lead, too, mixed with the clay, makes the vessels sustain violent degrees and sudden alterations of heat surprisingly well: crude clay, reduced to a kind of sand by violent heat, and then mixed with raw clay, is also found to furnish vessels excellently fitted for those operations where. where sand might be corroded: but of all kinds of earthen ware, the most perfect is porcelain, composed of the finest clay mixed with a stony matter capable of melting in a violent heat. This, however, is too costly an article for general use. Reaumur discovered a method of imitating porcelain, by melting the coarser kinds of glass with a mixture of sand and clay; this has been found to be nearly of the colour of porcelain, to be much stronger than glass, and to bear the most sudden changes of heat and cold that we have occasion to apply. There has not hitherto been any manufacture of this ware, and of course it has not come into general use.

The common earthen vessels are of a loose porous texture; and hence are apt to imbibe a considerable quantity of certain liquids, particularly of those of the saline kind; which soon discover that they have penetrated the vessel, by shooting into saline efflorescences on the outside. Those which are glazed have their glazing corroded by acids: by vinegar, and the acid juices of fruits, as well as by the stronger acids of the mineral kingdom. And as this glazing consists chiefly of vitrified lead, the impregnation which it communicates to these liquors is of a very dangerous kind. If vinegar be boiled for some time in a glazed earthen vessel, it will yield, on being infusoried, a purgative plumbi, that is, a salt composed of lead, and the acetic acid.

The vessels called, from their hardness and compactness, stone ware, are in a good measure free from the inconveniences of the coarser earthen ones. Their glazing being a part of the clay itself, superficially vitrified by means of the fumes of common salt, appears to be proof against acids.

Glass vessels suffer no corrosion, and give no taint, in any of the pharmaceutic operations. When, therefore, they are made of a proper thinness, when they are well annealed, and when blown into a spherical form so that the heat may be equally applied, they are preferable to all others, where great and sudden changes of heat and cold are not to take place, and where strength is not required: what is called the flint-glass, which contains a quantity of lead in its composition, is the best for chemical purposes.

Weights.

Two different kinds of weights are made use of in this country; one in the merchandise of gold and silver; the other for almost all other goods. The first we call Troy, the latter Avoirdupois weight.

The goldsmiths divide the Troy pound into twelve ounces; the ounce into 20 pennyweights; and the pennyweight into 24 grains. The Avoirdupois pound is divided into 16 ounces; and the ounce into 16 parts, called drams.

The pound of the London and Edinburgh dispensaries is that of the goldsmiths, divided in the following manner:

| Weight | Contains | |----------|----------| | The pound | Twelve ounces | | The ounce | Eight drams | | The dram | Three scruples | | The scruple | Twenty grains |

The grain is equal to the goldsmith's grain.

The medical or Troy pound is less than the Avoirdupois, but the ounce and the dram greater. The Troy pound contains 5760 grains; the Avoirdupois 7000 grains. The Troy ounce contains 480 grains; the Avoirdupois only 437½. The Troy dram 60; the Avoirdupois dram somewhat more than 27. Eleven drams Avoirdupois are nearly equal to five drams Troy; 12 ounces Avoirdupois to nearly 11 ounces Troy; and 19 pounds Avoirdupois are equal to somewhat more than 23 pounds Troy.

These differences in our weights have occasioned great confusion in the practice of pharmacy. As the druggists and grocers sell by the Avoirdupois weight, the apothecaries have not in general kept any weights adjusted to the Troy pound greater than two drams, using Avoirdupois ounces. By this means it is apparent, that in all compositions, where the ingredients are prescribed, some by pounds and others by ounces, they are taken in a wrong proportion to each other; and the same happens where any are directed in lesser denominations than the ounce, as these subdivisions used by the apothecaries are made to a different ounce.

Measures.

The measures employed in pharmacy are the common wine measures.

| Measure | Contains | |---------|----------| | A gallon | Eight pints (librae) | | The pint | Sixteen ounces | | The ounce | Eight drams |

Though the pint is called by Latin writers libra or for wine, there is not any known liquor of which a pint measure answers to that weight. A pint of the highest rectified spirit of wine exceeds a pound by above half an ounce; a pint of water exceeds it by upwards of three ounces; and a pint of oil of vitriol weighs more than two pounds and a quarter.

The Edinburgh College, sensible of the many errors from the promiscuous use of weights and measures, and of their different kinds, have in the last edition of their Pharmacopoeia entirely rejected measures, and employ the Troy weight in directing the quantity either of solid or fluid substances. They have, however, taken all possible care that the proportion of the simples and strength of the compounds should neither be increased nor diminished by this alteration. This change in the Edinburgh Pharmacopoeia must be very particularly adverted to. And it is, we think, to be regretted, that the London College have not in the last edition of their Pharmacopoeia followed the same plan.

A table of the weights of certain measures of different fluids may on many occasions be useful, both for the weights afflicting the operator in regulating their proportions in certain cases, and showing the comparative gravities of the fluids themselves. We here insert such a table fluids may for a pint, an ounce, and a dram measure, of those liquids whose gravity has been determined by experiments that can be relied on. The wine gallon contains 231 cubic inches; whence the pint contains 28⅔, the ounce 1⅓, and the dram ⅓ of a cubic inch. ### PHARMACY

#### CHAP. III. Of the Pharmaceutical Operations.

#### Sect. I. Solution.

Solution is an intimate commixture of solid bodies with fluids into one seemingly homogeneous liquor. The dissolving fluid is called a menstruum or solvent; both in the humid and dry way.

Objections have been made, and perhaps with propriety, to these terms; as it is supposed that the two bodies uniting in solution act reciprocally on each other; there is, however, no danger from the words themselves, if we do not derive them from a mistaken theory. Solution cannot take place, unless one of the bodies, at least, be in a fluid state; and this fluidity is effected either by water or fire; hence solution is said to be performed in the humid or in the dry way. Thus, for instance, if any quantity of brimstone be dissolved in a solution of fixed alkali, the brimstone is said to be dissolved in the humid way; but if the brimstone be dissolved by melting it in a pan with the dry alkali, the solution is said to be done in the dry way. The hepar sulphuris is the same in both. Another kind of solution resembling that by the dry way, is, however, to be carefully distinguished from it: if, for example, a piece of Glauber's salt is put into a pan over the fire, the salt very soon assumes a liquid state; but on continuing the heat, it loses its fluidity, and becomes a white powder: this powder is the salt freed from its water, and it is found to be very refractory. This liquidity depended on the water of crystallization being enabled by the heat to keep the salt in solution, and the salt ceased to be fluid as soon as its crystallizing water was evaporated. This kind of solution, then, differs not from the first, or humid way.

If one of the two bodies to be united is transparent, the solution, if complete, is a transparent compound: this is the case in solutions of alkalis and calcareous earths in acids. But if the solution be opaque and milky, as is the case with soap and water, it is then considered as incomplete.

The principal menstrua used in pharmacy are, wa-

| Substance | Pint weighs | Ounce measure | Dram measure | Grains | |----------------------------|------------|---------------|--------------|--------| | **Inflammable Spirits** | | | | | | Æthereal spirit of wine | 11 1 36 | 336 | 42 | | | Highly rectified spirit of wine | 12 5 20 | 380 | 47 1/2 | | | Common rectified spirit of wine | 13 2 40 | 400 | 50 | | | Proof spirit | 14 1 36 | 426 | 53 1/2 | | | Dulcified spirit of salt | 14 4 48 | 438 | 55 1/2 | | | Dulcified spirit of nitre | 15 2 40 | 460 | 57 1/2 | | | **Wines** | | | | | | Burgundy | 14 1 36 | 426 | 53 1/2 | | | Red port | 15 1 36 | 456 | 57 | | | Canary | 15 6 40 | 475 | 59 1/2 | | | **Expressed Oils** | | | | | | Oil olive | 14 0 0 | 420 | 52 1/2 | | | Linseed oil | 14 2 8 | 428 | 53 1/2 | | | **Essential Oils** | | | | | | Oil of turpentine | 12 1 4 | 364 | 45 1/2 | | | of orange-peel | | 408 | 51 | | | of juniper-berries | | 419 | 52 1/2 | | | of rosemary | | 430 | 53 1/2 | | | of origanum | | 432 | 54 | | | of caraway seeds | | 432 | 54 | | | of nutmegs | | 436 | 54 1/2 | | | of savin | | 443 | 55 1/2 | | | of hyssop | | 443 | 55 1/2 | | | of cumin-feed | | 448 | 56 | | | of mint | | 448 | 56 | | | of pennyroyal | | 450 | 56 1/2 | | | of dill-feed | | 457 | 57 1/2 | | | of fennel-feed | | 458 | 57 1/2 | | | of cloves | | 476 | 59 1/2 | | | of cinnamon | | 576 | 69 1/2 | | | of sassafras | | 593 | 62 1/2 | | | **Alkaline Liquors** | | | | | | Aqua kali puri, Pharm. Lond.| 16 0 0 | 480 | 60 | | | Spirit of sal ammoniac | 17 1 10 | 514 1/2 | 64 1/2 | | | Strong soap boilers ley | 17 6 24 | 534 | 66 1/2 | | | Lixivium tartari | 24 0 0 | 720 | 90 | | | **Acid Liquors** | | | | | | Wine-vinegar | 15 3 44 | 464 | 58 | | | Beer-vinegar | 15 6 56 | 476 | 59 1/2 | | | Glauber's spirit of salt | 17 4 0 | 525 | 65 1/2 | | | Glauber's spirit of nitre | 20 2 40 | 610 | 76 1/2 | | | Strong oil of vitriol | 28 5 20 | 860 | 107 1/2 | | | **Animal Fluids** | | | | | | Urine | 15 5 20 | 470 | 58 1/2 | | | Cows milk | 15 6 40 | 475 | 59 1/2 | | | Asses milk | 16 0 0 | 480 | 60 | | | Blood | 16 1 4 | 484 | 60 1/2 | | | **Waters** | | | | | | Distilled water | 15 1 50 | 456 1/2 | 57 | | | Rain-water | 15 2 40 | 460 | 57 1/2 | | | Spring-water | 15 3 12 | 462 | 57 1/2 | | | Sea-water | 15 5 20 | 470 | 58 1/2 | | | **Quicksilver** | 214 5 20 | 6440 | 805 | |

Eight ounces by weight of distilled water dissolved.

| Substance | oz. dr. gr. | |----------------------------|-------------| | Of refined sugar | 24 0 0 | | Green vitriol | 9 4 0 | | Blue vitriol | 9 0 0 | | White vitriol | 4 4 0 | | Epom salt | 4 0 0 | | Purified nitre | 4 0 0 | | Soluble tartar | 4 0 0 | | Common salt | 3 4 0 | | Sal gemmæ | 3 4 0 | Though great care appears to have been taken in making these experiments, it is not to be expected that the proportions of the several salts, soluble in a certain quantity of water, will always be found exactly the same with those above set down. Salts differ in their solubility according to the degree of their purity, perfection, and dryness: the vitriols, and the artificial compound salts in general, differ remarkably in this respect, according as they are more or less impregnated with the acid ingredient. Thus vitriolated tartar; perfectly neutralized, is extremely difficult of solution; the matter which remains in making Glauber's spirit of nitre is no other than a vitriolated tartar; and it dissolves so difficulty, that the operator is obliged to break the retort in order to get it out; but on adding more of the vitriolic acid, it dissolves with ease. Hence many have been tempted to use an over-proportion of acid in this preparation: and we frequently find in the shops, under the name of vitriolated tartar, this acid soluble salt. The degree of heat occasions also a remarkable difference in the quantity of salt taken up: in very cold weather, 8 ounces of water will dissolve only about one ounce of nitre; whereas in warm weather, the same quantity will take up three ounces or more. To these circumstances are probably owing, in part, the remarkable differences in the proportionable solubilities of salts, as determined by different authors. It is observable that common salt is less affected in its solubility by a variation of heat than any other; water in a temperate state dissolving nearly as much of it as very hot water: and accordingly this is the salt in which the different experiments agree the best. In the experiments of Hoffmann, Neumann, and Petit, the proportion of this salt, on a reduction of the numbers, comes on exactly the same, viz. three ounces of the salt to eight of water; Dr Brownrigg makes the quantity of salt a little more; Dr Grew, a dram and a scruple more; and Eller, as appears in the above table, four drams more: so that in the trials of six different persons, made probably in different circumstances, the greatest difference is only one fifth of the whole quantity of salt; whereas in some other salts there are differences of twice or thrice the quantity of the salt. In the experiments from which the table is drawn, the water was of the temperature of between 40 and 42 degrees of Fahrenheit's thermometer, or above freezing by about one-seventh of the interval between freezing and the human heat.

Some salts omitted by Eller are here subjoined; the first is taken from Dr Grew, and the other four from Neumann.

Eight ounces of water dissolved,

| oz. dr. gr. | |-------------| | Of fixed alkaline salt | above 8 0 0 | | Sal diureticus | 8 0 0 |

Sugar-candy, both brown and white 9 0 0

Sugar of milk 0 2 40

Essential salt of sorrel 0 1 20

Though water takes up only a certain quantity of one kind of salt, yet when saturated with one, it will still dissolve some portion of another; and when it can bear no more of either of these, it will still take up a third, without letting go any of the former. The principal experiments of this kind which have been made relative to pharmaceutic subjects, are exhibited in the following table; of which the two first articles are from Grew, and the others from Eller.

Water, 32 parts by weight,

| Fully saturated with | dissolved afterwards | |---------------------|----------------------| | Nitre | Sal ammoniac 10 | | Common salt | Nitre | | Fixed alkali | Common salt | | Volatile alkali | Nitre near | | Sal ammoniac | Fixed alkali | | Soluble tartar | Nitre | | Vitriolated tartar | Fixed alkali | | Glauber's salt | Nitre | | Epson salt | Sugar | | Borax | Fixed alkali |

In regard to the other classes of bodies for which water is a menstruum, viz. those of the gummy gelatinous kind, there is no determinate point of saturation: the water unites readily with any proportions of them, forming with different quantities liquor of different consistence. This fluid takes up likewise, when assisted by trituration, the vegetable gummy resins, as ammoniac and myrrh; the solutions of which, though imperfect, that is, not transparent, but turbid and of a milky hue, are nevertheless applicable to valuable purposes in medicine. It mingles with vinous spirits, with acid and alkaline liquors, not with oils, but imbibes some of the more subtle parts of essential oils, so as to become impregnated with their smell and taste.

Rectified spirit of wine, or rather alcohol, is the menstruum of the essential oils and resins of vegetables; of the pure distilled oils, and several of the colouring and wine, or medicinal parts of animals; of some mineral bituminous coals, the substances, as of ambergris; and of soaps, though it does not act upon the expressed oil and fixed alkaline salt, of which soap is composed: whence, if soap contains any superfluous quantity of either the oil or salt, of vegetable it may by means of this menstruum be excellently purified. It dissolves, by the afflatus of heat, volatile alkaline salts; and more readily the neutral ones, composed either of fixed alkali and the acetous acid, as the sal diuretics, or of the volatile alkali and the nitrous acid, as also the salt of amber, &c. It mingles with water and with acids; not with alkaline lixivias.

Oils dissolve vegetable resins and balsams, wax, animal-fats, mineral bitumens, sulphur, and certain metallic substances, particularly lead. The expressed oils dissolve various substances, for most of these bodies, more powerful menstrua than those obtained by distillation; as the former are more capable of sustaining, without injury, a strong heat, which is in most cases necessary to enable them to act. It is said, that one ounce of sulphur will dissolve in three ounces of expressed oil, particularly linseed. All acids dissolve alkaline salts, alkaline earths, and metallic substances. The different acids differ greatly in their action upon these last; one dissolving only some particular metals; and another, others.

The vegetable acids dissolve a considerable quantity of zinc, iron, copper, lead, and tin; and extract so much from the metallic part of antimony, as to become powerfully emetic: they dissolve lead more readily, if the metal be previously calcined by fire, than in its metallic state.

The marine acid dissolves zinc, iron, and copper; and though it scarcely acts on any other metallic substance in the common way of making solutions, it may nevertheless be artfully combined with them all except gold. The corrosive sublimate, and antimonial caustic of the shops, are combinations of it with mercury and the metallic part of antimony, effected by applying the acid, in the form of fume, to the subjects, at the same time also strongly heated.

The nitrous acid is the common menstruum of all metallic substances, except gold and the metallic part of antimony; of which two, the proper solvent is a mixture of the nitrous and marine acids, called aqua regia.

The vitriolic acid, diluted with water, easily dissolves zinc and iron. In its concentrated state, and assisted by a boiling heat, it may be made to corrode, or imperfectly dissolve, most of the other metals.

The aerial acid dissolves iron, zinc, and calcareous earth; and those solutions must be conducted without heat.

Alkaline lixivia dissolve oils, resinous substances, and sulphur. Their power is greatly promoted by the addition of quicklime; instances of which occur in the preparation of soap, and in the common caustic. Thus acuated, they reduce the flesh, bones, and other solid parts of animals, into a gelatinous matter. This increased acrimony in alkaline salts is owing to the abstraction of their fixed air; that acid having a greater attraction for quicklime than for alkalis.

Solutions made in water and in spirit of wine possess the virtues of the body dissolved; while oils generally sheath its activity, and acids and alkalis vary its quality. Hence watery and spirituous liquors are the proper menstrua of the native virtues of vegetable and animal matters.

Most of the foregoing solutions are easily effected, by pouring the menstruum on the body to be dissolved, and suffering them to stand together for some time exposed to a suitable warmth. A strong heat is generally requisite to enable oils and alkaline liquors to perform their office; nor will acids act on some metallic bodies without its assistance. The action of watery and spirituous menstrua is likewise expedited by a moderate heat; though the quantity which they afterwards keep dissolved is not, as some suppose, by this means increased: all that heat occasions these to take up, more than they would do in a longer time in the cold, will, when the heat ceases, subside again. This at least is most commonly the case, though there may be some instances of the contrary.

The action of acids on the bodies which they dissolve, is generally accompanied with heat, effervescence, and a copious discharge of fumes. The fumes which arise during the solution of some metals in the vitriolic acid, prove inflammable: hence in the preparation of the artificial vitriols of iron and zinc, the operator ought to be careful, especially where the solution is made in a narrow mouthed vessel, lest by the imprudent approach of a candle the exhaling vapour be set on fire. This vapour is the inflammable air of Dr Priestley and other modern chemists.

There is another species of solution, in which the moisture of the air is the menstruum. Fixed alkaline salts, and those of the neutral kind, composed of alkaline salts and the vegetable acids, or of soluble earths and any acid, except the vitriolic, and some metallic salts, on being exposed for some time to a moist air, gradually attract its humidity, and at length become liquid. Some substances, not dissoluble by the application of water in its grossest form, as the butter of antimony, are easily liquefied by this slow action of the aerial moisture. This process is called de-liquation.

**Sect. II. Extraction.**

The liquors which dissolve certain substances in their pure state, serve likewise to extract them from admixtures of other matter. Thus ardent spirit, the which diverse substances are also useful to those of the mucilaginous and saline; the inactive or earthy parts remaining untouched by both. Watering them extracts likewise from many plants, substances which from adhesion themselves it has little effect upon; even essential mixtures of oils being, as we have formerly observed, rendered soluble in that fluid by the admixture of gummy and saline matter, of which all vegetables participate in a greater or less degree. Thus many of the aromatic plants, and most of the bitters and astringents, yield their virtues to this menstruum.

Extraction is performed, by macerating or sleeping the subject in its appropriated menstruum in the cold; performing or diggling or circulating them in a moderate warmth; extraction, or infusing the plant in the boiling liquor, and suffering them to stand in a covered vessel till grown cold; or actually boiling them together for some time. If the vegetable matter is itself succulent and watery, it is sometimes only necessary to express the juice, and evaporate it to the proper consistence.

The term digestion is sometimes used for maceration; and in this case the process is directed to be performed without heat: where this circumstance is not expressed, digestion always implies the use of heat. Circulation differs from digestion only in this, that the steam, into which a part of the liquor is resolved by the heat, is, by means of a proper disposition of the vessels, condensed and conveyed back again upon the subject. Digestion is usually performed in a matraf (or bolt-head), Florence flask, or the like; either of which may be converted into a circulatory vessel, by inverting another into the mouth, and securing the juncture with a piece of wet bladder. A single matraf, if its neck be very long and narrow, will answer the purpose as effectually; the vapour cooling and condensing before it can rise to the top: in a vessel of this kind, even spirit of wine, one of the most volatile liquors we know, may be boiled without any considerable loss: the use of this instru- Heat greatly expedites extraction; but by this means proves as injurious to some substances, by occasioning the menstruum to take up their groser and more ungrateful parts, as it is necessary for enabling it to extract the virtues of others. Thus guaiacum and logwood impart little to aqueous liquors without a boiling heat; whilst even a small degree of warmth proves greatly prejudicial to the fine bitter of cardus benedictus. This plant, which infused in boiling, or digested in feebly hot water, gives out a nauseous taste, so offensive to the stomach as to promote vomiting, yields to the cold element a grateful balsamic bitter.

As heat promotes the dissolving power of liquids; so cold, on the other hand, diminishes it. Hence tinctures or extractions made by a considerable heat, deposit in cold weather a part of their contents, and thus become proportionally weaker: a circumstance which deserves particular regard.

**Sect. III. Depuration.**

There are different methods of depurating or purifying liquors from their feculencies, according as the liquor itself is more or less tenacious, or the feculent matter of greater or less gravity.

Thin fluids readily deposit their more ponderous impurities upon standing at rest for some time in a cool place; and may then be decanted or poured off clear, by inclining the vessel.

Glutinous, unctuous, or thick substances, are to be liquefied by a suitable heat; when the groser feculencies will fall to the bottom, the lighter arising to the surface to be depurated or scummed off.

Where the impurities are neither so ponderous as to subside freely to the bottom, nor so light as to arise readily to the surface, they may be separated in great measure by colature through strainers of linen, woollen, or other cloth; and more perfectly by filtration through a soft bibulous kind of paper made for the purpose.

The grey paper, which covers pill-boxes as they come from abroad, is one of the best for this purpose: it does not easily break when wetted, or tinge the liquor which passes through it, which the reddish sort called blooming paper frequently does. The paper is supported by a funnel or piece of canvas fixed in a frame. When the funnel is used, it is convenient to put some straws or small sticks between the paper and its sides, to prevent the weight of the liquor from pressing the paper so close to it, as not to allow room for the fluid to transude. In some cases a funnel made of wire is put between the paper and the glass funnel. There is also a kind of glass funnel with ridges down its sides made on purpose for this use.

Glutinous and unctuous liquors, which do not easily pass through the pores of a filter or strainer, are clarified by beating them up with whites of eggs; which concreting and growing hard when heated, and entangling the impure matter, arise with it to the surface: the mixture is to be gently boiled till the scum begins to break, when the vessel is to be removed from the fire, the crust taken off, and the liquor passed thro' a flannel bag.

Decantation, colature, and filtration, are applicable to most of the medicated liquors that stand in need of purification. Depurature and clarification very rarely have place; since these, along with the impurities of the liquor, frequently separate its medicinal parts. Thus, if the decoction of poppy heads, for making diacolium, be folicitously scummed or clarified, the medicine will lose almost all that the poppies communicated; and instead of a mild opiate, turns out little other than a plain syrup of sugar.

It may be proper to observe, that the common sorts of filtering paper are apt to communicate a disagreeable flavour: and hence in filtering fine bitters or other liquors, whose gratefulness is of primary consequence, the part which passes through first ought to be kept apart for inferior purposes.

**Sect. IV. Crystallization.**

Water, assisted by heat, dissolves a larger proportion of most saline substances than it can retain when grown cold; hence, on the abatement of the heat, a part of the salt separates from the menstruum, and concretizes at the sides and bottom of the vessel. The concretions, unless too hastily formed by the sudden cooling of the liquor, or disturbed in their coalescence by agitation, or other similar causes, prove transparent and of regular figures, resembling in appearance the natural spring-crystals.

Salts, dissolved in a large quantity of water, may in like manner be recovered from it in their crystalline form, by boiling down the solution, till so much of the fluid has exhaled as that the remainder will be too little to keep the salt dissolved when grown perfectly cold. It is customary to continue the evaporation till the salt shows a disposition to concrete even from the hot water, by forming a pellicle on that part which is least hot, viz. on the surface. If large, beautiful, and perfectly figured crystals are required, this point is somewhat too late: for if the salt thus begins to coalesce whilst considerably hot, on being removed into a cold place its particles will run too hastily and irregularly together: the pellicle at the same time falling down through the liquor, proves a farther disturbance to the regularity of the crystallization.

In order to perform this process in perfection, the evaporation must be gentle, and continued no longer than till some drops of the liquor, let fall on a cold glass-plate, discover crystalline filaments. When this mark of sufficient exhalation appears, the vessel is to be immediately removed from the fire into a less warm but not cold place, and covered with a cloth to prevent the access of cold air, and consequently the formation of a pellicle.

The fixed alkalis, especially the mineral, when fully saturated with fixed air or the aerial acid, assume a crystalline form; but these crystals are not so perfect as when the same alkalis are united with the other acids; the volatile alkalis cannot crystallize, because they escape before the menstruum exhales.

Some even of the other neutral salts, particularly those of which certain metallic bodies are the basis, are so strongly retained by the aqueous fluid, as not to exhibit any appearance of crystallization, unless some other other substance be added, with which the water has a greater affinity. The Table of Affinity shows that spirit of wine is such a substance; by the prudent addition of which, these kinds of salt separate freely from the menstruum, and form large and beautiful crystals scarcely obtainable by any other means.

The operator must be careful not to add too much of the spirit; lest, instead of a gradual and regular crystallization, the basis of the salt be hastily precipitated in a powdery form. One-twentieth part of the weight of the liquor will in most cases be sufficient, and in some too large a quantity.

Different salts require different quantities of water to keep them dissolved; and hence, if a mixture of two or more be dissolved in this fluid, they will begin to separate and crystallize at different periods of the evaporation. Upon this foundation, salts are freed not only from such impurities as water is not capable of dissolving and carrying through the pores of a filter, but likewise from admixtures of each other; that which requires most water to dissolve shooting first into crystals.

It is proper to remark, that a salt, when crystallizing, still retains and combines with a certain portion of water: this water is not essential to the salt as a salt, but is essential to a salt as being crystallized; it is therefore called by the chemists the water of crystallization. The quantity of this water varies in different salts: In some of them, as in Glauber's salt, alum, and copperas, it makes up about one half of their weight; in others, as in nitre, common salt, and especially selenites, it is in very small quantity. As salts unite to the water of their crystallization by their attraction for water alone, we accordingly find that this water is perfectly pure, and contains, in complete crystals, no substance foreign to the salt. Salts not only differ in the quantity of water necessary to their solution, but some of them are also soluble with equal facility in cold as in hot water. Sometimes then we employ evaporation; sometimes cooling; and at other times both these expedients are used alternately, to separate different salts dissolved in the same liquor. It is obvious, then, that those which are nearly or equally soluble in cold as in boiling water, can only be crystallized by evaporation; those again, which are much more soluble in boiling than in cold water, are to be separated by cooling. Of the first of these is common or marine salt; of the latter is nitre or saltpetre. It remains, then, that we should know how to separate these two salts, when both of them happen to be dissolved in the same water; this method consists in alternate evaporation and cooling. If in such a solution a pellicle appears in the boiling liquor before crystals can be formed in the cooling, we then conclude that the common salt predominates: In this case we evaporate the water, and separate the common salt as fast as it is formed, till the liquor on cooling shows crystals of nitre: we then allow the nitre to crystallize by cooling. After all the nitre which had been dissolved by the heat alone has now separated by cooling, we resume the evaporation, and separate the common salt till the cooling liquor again shows crystals of nitre. We thus repeat the same series of operations, by which means these two salts may be alternately crystallized; the one by evaporation, the other by cooling, till they are perfectly separated from each other. If in the beginning of the operation the liquor had, upon trial, given crystals of nitre by cooling, before any pellicle appeared on its surface when boiling, this would have indicated that the nitre was predominant in the solution; the nitre in this case would have been crystallized, first by cooling, till the quantity of nitre exceeding that of the common salt having been separated, the common salt would next have crystallized in its turn by evaporation. The example we have now given may be applied to other salts, or to a number of salts which may happen to be dissolved in the same liquor. For though there are few so completely soluble in cold water as common salt, and few so scantily as nitre; yet there are scarcely two salts which either precisely show the same solubility or the same appearance of their crystals. It is obvious, too, that by crystallization we discover the peculiar predominant salt in any solution of mixed saline matter; but as one salt always takes down a small portion of another, it is necessary to redissolve the first products, and repeat the crystallization, in order to render the separation complete.

We see, then, that though the crystal appearance and form does not alter the salt itself, yet that this process affords an elegant method of discovering compound solutions of salts, of judging of their purity, and lastly of separating different salts very completely from each other. Crystallization, then, is one of the most important agents in pharmacy, and ought to be well understood. We shall attempt to explain the particular management in crystallizing particular salts, when we come to treat of each of them separately.

Sect. V. Precipitation.

By this operation bodies are recovered from their Nature of solutions by means of the addition of some other substance, with which either the menstruum or the body dissolved have a greater affinity than they have with each other.

Precipitation, therefore, is of two kinds; one, where this operation is performed by adding the substance superadded unites with the menstruum, and occasions that before dissolved to be thrown down; the other, in which it unites with the dissolved body, and falls along with it to the bottom. Of the first, we have an example in the precipitation of sulphur from alkaline lixivium by the means of acids; of the second, in the precipitation of mercury from aquafortis by felspar, or its acid.

The subjects of this operation, as well those which are capable of being precipitated as those which precipitate them, will readily appear from inspection of the Table of Affinity. See Chemistry, page 438. The manner of performing it is so simple, as not to stand in need of any particular directions; no more being required than to add the precipitant by degrees as long as it continues to occasion any precipitation. When the whole of the powder has fallen, it is to be well edulcorated, that is, washed in several fresh parcels of water, and afterwards dried for use.

Where metals are employed as precipitants, as in the purification of martial vitriol from copper by the addition of fresh iron, they ought to be perfectly clean and free from any rusty or greasy matter; otherwise they will not readily, if at all, dissolve, and consequently ly the precipitation will not succeed; for the substance to be precipitated separates only by the additional one dissolving and taking its place. The separated powder often, instead of falling to the bottom, lodges upon the precipitant; from which it must be occasionally shaken off, for reasons sufficiently obvious.

Though in this operation the precipitated powder is generally the part required for use, yet some advantage may frequently be made of the liquor remaining after the precipitation. Thus when fixed alkaline salt is dissolved in water, and sulphur dissolved in this lixivium, the addition of acids separates and throws down the sulphur only in virtue of the acid uniting with and neutralizing the alkali by which the sulphur was held dissolved; consequently, if the precipitation be made with the vitriolic acid, and the acid gradually dropped till the alkali be completely saturated, that is, as long as it continues to occasion any precipitation or turbidness, the liquor will yield, by proper evaporation and crystallization, a neutral salt composed of the vitriolic acid and fixed alkali, that is, vitriolated tartar. In like manner, if the precipitation be made with the nitrous acid, a true nitre may be recovered from the liquor; if with the marine, the salt called *spiritus salis marini conglobatus*; and if with the acid of vinegar, the *sal diureticus*.

**Sect. VI. Evaporation.**

Evaporation, the third method of recovering solid bodies from their solutions, is effected by the means of heat; which evaporating the fluid part, that is, forcing it off in steam, the matter which was dissolved therein is left behind in its solid form.

The general rules for evaporation are, to place the matter in a flat, shallow, wide vessel, so that a large surface of the liquor may be presented to the air; for it is only from the surface that evaporation takes place. The degree of heat ought to be proportioned to the volatility of the substance to be evaporated, and to the degree of the fixity of the matter to be left; thus, the less fixed the matter to be left is, and the more strongly it adheres to the volatile parts, the less the degree of heat ought to be; and in such cases, too, a forcible current of air is sometimes scarcely admissible; on the contrary, when the matter to be evaporated is not very volatile, and when the matter to be left is very fixed, and does not adhere strongly to the volatile part, the evaporation may be urged by a strong heat, aided by a current of air directed upon the surface of the liquor.

This process is applicable to the solutions of all these substances which are less volatile than the menstruum, or which will not exhale by the heat requisite for the evaporation of the fluid; as the solutions of fixed alkaline salts; of the gummy, gelatinous, and other inodorous parts of vegetables and animals in water; and of any resinous and odorous substances in spirit of wine.

Water extracts the virtues of sundry fragrant aromatic herbs, almost as perfectly as rectified spirit of wine; but the aqueous infusions are far from being equally suited to this process with those made in spirit, water carrying off the whole odour and flavour of the subject which that lighter liquor leaves entire behind it. Thus a watery infusion of mint loses in evaporation the smell, taste, and virtues, of the herb; whilst a tincture drawn with pure spirit yields on the same treat-

ment a thick balsamic liquor, or solid gummy resin, extremely rich in the peculiar qualities of the mint.

In evaporating these kinds of liquors, particular care must be had, towards the end of the process, that the heat be very gentle; otherwise the matter as it grows thick will burn to the vessel, and contract a disagreeable smell and taste: this burnt flavour is called *empyrea*. The liquor ought to be kept stirring during the evaporation; otherwise a part of the matter concretes on the surface exposed to the air, and forms a pellicle which impedes the farther evaporation.

**Sect. VII. Distillation.**

In the foregoing operation fluids are rarefied by heat into steam or vapour, which is suffered to exhale in the air, but which it is the business of distillation to collect, observe, and preserve. For this purpose the steam is received in proper vessels, luted to that in which the subject is contained; and being there cooled, condenses into a fluid form again.

There are two kinds of distillation; by the one, the more subtle and volatile parts of liquors are elevated from the groser; by the other, liquids incorporated with solid bodies are forced out from them with vehemence by fire.

To the first belong the distillation of the pure inflammable spirit from vinous liquors; and of such of the active parts of vegetables as are capable of being extracted by boiling water or spirit, and at the same time of arising along with their steam.

As boiling water extracts or dissolves the essential oils of vegetables, while blended with the other principles of the subject, without saturation, but imbibes only a determinate, and that a small proportion of them, in their pure state; as these oils are the only substances contained in common vegetables, which prove totally volatile in that degree of heat; and as it is in them that the virtues of aromatics, and the peculiar odour and flavour of all plants, reside;—it is evident, that water may be impregnated by distillation, with the more valuable parts of many vegetables: that this impregnation is limited, the oil arising in this process pure from those parts of the plant which before rendered it soluble in water without limitation; hence the greatest part of the oil separates from the distilled aqueous liquor, and, according to its greater or less gravity, either sinks to the bottom or swims on the surface: that consequently infusions and distilled waters are very different from each other: that the first may be rendered stronger by pouring the liquor on fresh parcels of the subject; but that the latter cannot be in like manner improved by cohabiting or redistilling them from fresh ingredients.

As the oils of many vegetables do not freely distil with a less heat than that in which water boils; as rectified spirit of wine is not susceptible of this degree of heat; and as this menstruum totally dissolves these oils in their pure state; it follows, that spirit elevates far less from most vegetables than water; but that nevertheless the distilled spirit, by keeping all that it does elevate perfectly dissolved, may, in some cases, prove as strong of the subject as the distilled water. The more gentle the heat, and the slower the distillation goes on, the volatile parts are the more perfectly separated in their native state. It may be observed, that as the parts which are preserved in evaporation cannot arise in distillation, the liquor remaining after the distillation, properly depurated and insipidized, will yield the same extracts as those prepared from the tincture or decoction of the subject made on purpose for that use; the one of these operations collecting only the volatile parts, and the other, the more fixed; so that where one subject contains medicinal parts of both kinds, they may thus be obtained distinct, without one being injured by the process which collects the other.

The subjects of the second kind of distillation are, the gross oils of vegetables and animals, the mineral acid spirits, and the metallic fluid quicksilver; which as they require a much stronger degree of heat to elevate them than the foregoing liquors can sustain, so they likewise condense without arising so far from the action of the fire. The distillation of these is performed in low glass vessels, called, from their neck being bent to one side, retorts; to the farther end of the neck a receiver is fitted, which standing without the furnace, the vapours soon condense in it, without the use of a refrigeratory: nevertheless, to promote this effect, some are accustomed, especially in warm weather, to cool the receiver, by occasionally applying wet clothes to it, or keeping it partly immersed in a vessel of cold water.

The vapours of some substances are so sluggish, or strongly retained by a fixed matter, as scarce to arise even over the low neck of the retort. There are most commodiously distilled in straight-necked earthen vessels called longnecks, laid on their sides, so that the vapour passes off laterally with little or no ascent; a receiver is fitted to the end of the neck without the furnace. In this manner, the acid spirit of vitriol is distilled. The matter which remains in the retort or longneck, after the distillation, is vulgarly called caput mortuum.

In these distillations, a quantity of elastic air is frequently generated; which, unless an exit be allowed, blows off or bursts the receiver. The danger of this may in good measure be prevented, by slowly raising the fire; but more effectually by leaving a small hole in the luting, to be occasionally opened or stopped with a wooden plug; or inserting at the juncture an upright pipe of such a height, that the steam of the distilling liquor may not be able to rise to the top; but it is still better done by fitting to the apparatus other vessels, by which their vapours may be condensed. For the process of distilling, and the apparatus made use of, see Distillation; and Chemistry, no 574.

Sect. VIII. Sublimation.

As all fluids are volatile by heat, and consequently capable of being separated, in most cases, from fixed matters, by the foregoing process; so various solid bodies are subjected to a similar treatment. Fluids are said to distil, and solids to sublime; though sometimes both are obtained in one and the same operation. If the subliming matter concretes into a mass, it is commonly called a sublimate; if into a powdery form, flowers.

The principal subjects of this operation are, volatile alkaline salts; neutral salts, composed of volatile alkalis and acids, as sal ammoniac; the salt of amber, and flowers of benzoin; mercurial preparations; and sulphur. Bodies of themselves not volatile, are frequently made to sublime by the mixture of volatile ones; thus iron is carried up by sal ammoniac in the preparation of the flores martiales, or ferrum ammoniacale.

The fumes of solid bodies in close vessels rise but little way, and adhere to that part of the vessel where they concreted. Hence a receiver or condenser is less necessary here than in the preceding operation; a single vessel, as a matras, or tall phial, or the like, being frequently sufficient.

Sect. IX. Expression.

The press is chiefly made use of for forcing out the juices of succulent herbs and fruits, and the insipid oils of the unctuous seeds and kernels.

The harder fruits, as quinces, require to be previously well beat or ground; but herbs are to be only moderately bruised. The subject is then included in a hair bag, and pressed between wooden plates, in the common screw-press, as long as any juice runs from it.

The expression of oils is performed nearly in the same manner as that of juices; only here, iron-plates are substituted for the wooden ones there made use of. The subject is well pounded, and included in a strong canvas bag, between which and the plates of the press a haircloth is interposed.

The insipid oils of all the unctuous seeds are obtained, uninjured, by this operation, if performed without the use of heat; which, though it greatly promotes the extraction of the oil, at the same time impresses an ungrateful flavour, and increases its disposition to grow rancid.

The oils expressed from aromatic substances generally carry with them a portion of their essential oil; hence the smell and flavour of the expressed oils of nutmegs and mace. They are very rarely found impregnated with any of the other qualities of the subject; oil of mustard-seed, for instance, is as soft and void of acrimony as that of the almond, the pungency of the mustard remaining entire in the cake left after the expression.

Sect. X. Exsiccation.

There are two general methods of exsiccating or drying moist bodies; in the one, their humid parts are exhaled by heat; in the other, they are imbibed or absorbed by substances whose soft and spongy texture adapts them to that use. Bodies intimately combined with, or dissolved in a fluid, as recent vegetables and their juices, require the first; such as are only superficially mixed, as when earthy or indissoluble powders are ground with water, are commodiously separated from it by the second.

Vegetables and their parts are usually exsiccated by the natural warmth of the air: the assistance of a gentle artificial heat may, nevertheless, in general, be not only safely, but advantageously, had recourse to. By a moderate fire, even the more tender flowers may be dried, in a little time, without any considerable loss either of their odour or lively colour; which would both be greatly injured or destroyed by a more slow exsiccation in the air. Some plants, indeed, particularly larly those of the acrid kind, as horse-radish, scurvy-grass, and arum, lose their virtues by this process, however carefully performed; but far the greater number retain them unimpaired, and often improved.

The thicker vegetable juices may be excrated by the heat of the sun; or, where this is not sufficient, by that of a water-bath, or an oven moderately warm. The thinner juices may be gently boiled till they begin to thicken, and then treated as the foregoing. The process, termed infusification or evaporation, has been spoken of already. The juices of some plants, as arum root, briony root, orris root, wild cucumbers, &c., separate, upon standing for some time, into a thick part, which falls to the bottom; and a thin aqueous one, which swims above it: this last is to be poured off, and the first excrated by a gentle warmth. Preparations of this kind have been usually called fecule; that of the cucumber, to be spoken of in its place, is the only one which practice now retains.

Indissoluble bodies, mixed with water into a thick consistence, may be easily freed from the greatest part of it, by dropping them on a chalkstone, or some powdered chalk pressed into a smooth mass, which readily imbibes their humidity. Where the quantity of fluid is large, as in the edulcoration of precipitates, it may be separated by decantation or filtration.

We before observed, that one of the principal circumstances favouring fermentation, was a certain degree of moisture. Excration is therefore employed to dissipate humidity, and render vegetables thereby less liable to those changes produced by a kind of insensible fermentation.

Sect. XI. Comminution.

Comminution is the bare reduction of solid coherent bodies into small particles or powder. The methods of effecting this are various, according to the texture of the subject.

Dry friable bodies, or such as are brittle and not very hard, and mixtures of these with somewhat moist ones, are easily pulverised in a mortar.

For very light dry substances, resins, and the roots of tenacious texture, the mortar may in some cases be previously rubbed with a little sweet oil, or a few drops of oil be occasionally added: this prevents the finer powder of the first from flying off, and the others from cohering under the pestle. Camphor is commodiously powdered by rubbing it with a little rectified spirit of wine.

Tough substances, as woods, the peels of oranges and lemons, &c. are most conveniently rasped; and soft oily bodies, as nutmegs, passed through a grater.

Vol. XIV. Part I.

(c) Some attribute this effect to a diminution of the specific gravity of the body; and, at the same time, suppose the peculiar virtues of certain medicines, particularly mercury, to be in great measure owing to their gravity. If these hypotheses were just, it should follow, that the mercurial preparations, by being finely comminuted, would lose proportionably of their efficacy; and so indeed mercurius dulcis, for instance, has been supposed to do. But experience shows, that this is far from being the case; and that comminution by no means lessens but rather increases its power: when reduced to a great degree of subtlety, it passes readily into the habit, and operates, according to its quantity, as an alterative or a salagogue; while in a grosser form, it is apt to irritate the stomach and bowels, and run off by the intestines, without being conveyed into the blood. Sect. XII. Fusion.

Fusion is the reduction of solid bodies into a state of fluidity by fire. Almost all natural substances, the pure earths and the solid parts of animals and vegetables excepted, melt in proper degrees of fire; some in a very gentle heat, while others require its utmost violence.

Turpentine, and other soft resinous substances, liquefy in a gentle warmth; wax, pitch, sulphur, and the mineral bitumens, require a heat too great for the hand to support; fixed alkaline salt, common salt, nitre, require a red or almost white heat to melt them; and glass, a full white heat.

Among metallic substances, tin, bismuth, and lead, flow long before ignition; antimony likewise melts before it is visibly red-hot, but not before the vessel is considerably so; the regulus of antimony demands a much stronger fire. Zinc begins to melt in a red heat; gold and silver require a low white heat; copper a bright white heat; and iron an extreme white heat.

One body, rendered fluid by heat, becomes sometimes a menstruum for another, not fusible of itself in the same degree of fire. Thus red-hot silver melts on being thrown into melted lead less hot than itself; and thus if steel, heated to whiteness, be taken out of the furnace, and applied to a roll of sulphur, the sulphur instantly liquefying, occasions the steel to melt with it; hence the chatybs cum sulphure of the shops. This concrete, nevertheless, remarkably impedes the fusion of some other metals, as lead; which when united with a certain quantity of sulphur is scarce to be perfectly melted by a very strong fire. Hence the method, described in its place, of purifying zinc; a metal upon which sulphur has no effect from the lead so frequently mixed with it.

Sulphur is the only unmetallic substance which mingles in fusion with metals. Earthy, saline, and other like matters, even the calces and glasses prepared from metals themselves, float distinct upon the surface, and form what is called scoria or dros. Where the quantity of this is large in proportion to the metal, it is most commodiously separated by pouring the whole into a conical mould; the pure metal or regulus, though small in quantity, occupies a considerable height in the lower narrow part of the cone; and when congealed, may be easily freed from the scoria by a hammer. The mould should be previously greased, or rather smoked, to make the metal come freely out; and thoroughly dried and heated, to prevent the explosion which sometimes happens from the sudden contact of melted metals with moist bodies.

Sect. XIII. Calcination.

By calcination is understood the reduction of solid bodies, by the means of fire, from a coherent to a powdery state, accompanied with a change of their quality; in which last respect this process differs from coagulation.

To this head belong the burning of vegetable and animal matters, otherwise called fusion, incineration, or concremation; and the change of metals into a powder, which in the fire either does not melt or vitrifies, that is, runs into glass.

The metals which melt before ignition, are calcined by keeping them in fusion for some time. The free admission of air is essentially necessary to the success of this operation; and hence, when the surface of the metal appears covered with calx, this must be taken off or raked to one side, otherwise the remainder excluded from the air will not undergo the change intended. If any coal, or other inflammable matter which does not contain a mineral acid, be suffered to fall into the vessel, the effect expected from this operation will not be produced, and part of what is already calcined will be revived or reduced; that is, it will return into its metallic form again.

Those metals which require a strong fire for fusion, calcine with a much less heat than is sufficient to make them flow. Hence the burning or scorification of such iron or copper vessels as are long exposed to a considerable fire without defence from the air. Gold and silver are not calcinable by any degree of fire.

In calcination, the metals visibly emit fumes; nevertheless the weight of the calx proves greater than that of the metal employed. The antimonial regulus gains about one eleventh part of its weight; zinc sometimes one-tenth; tin above one-sixth; and lead in its conversion into minium often one fourth.

The calcination of metallic bodies, gold, silver, and mercury excepted, is greatly promoted by nitre. This salt exposed to the fire in conjunction with any inflammable substances, extricates their inflammable matter, and bursts with it into flame, accompanied with a hissing noise. This process is usually termed deflagration or detonation.

All the metallic calces and scoriae are revived into their metallic state by fusion with any vegetable or animal inflammable matter. They are all more difficult of fusion than the respective metals themselves; and scarcely any of them, those of lead and bismuth excepted, can be made to melt at all, without some addition, in the strongest fire that can be produced in the common furnaces. The additions called fluxes, employed for promoting the fusion, consist chiefly of fixed alkaline salts. A mixture of alkaline salt with inflammable matter, as powdered charcoal, is called a reducing flux, as contributing at the same time to bring the calx into fusion, and to revive it into metal. Such a mixture is commonly prepared from one part of nitre and two parts of tartar, by grinding them well together, setting the powders on fire with a bit of coal or a red-hot iron, then covering the vessel, and suffering them to deflagrate or burn till they are changed into a black alkaline coaly mass. This is the common reducing flux of the chemists, and is called from its colour the black flux. Metallic calces of scoriae, mingled with twice their weight of this compound, and exposed to a proper fire in a close covered crucible, melt and resume their metallic form; but though they received an increase of weight in the calcination, the revived metal is always found to weigh considerably less than the quantity from which the calx was made.

For a more particular account of all these processes, and an explanation of the principles on which they depend, see Chemistry paffim, and the articles themselves as they occur in the order of the alphabet. PART II. PREPARATIONS AND COMPOSITIONS.

Containing those of the London and Edinburgh Pharmacopoeias.

CHAP. I. The more Simple Preparations.

The preparation of some substances not soluble in water. I.

POUND these substances first in a mortar; then, pouring on a little water, levigate them on a hard and polished, but not calcareous, stone, that they may be made as fine as possible. Dry this powder on blotting-paper laid on chalk, and let it in a warm, or at least a dry, place, for some days.

In this manner are to be prepared,

Amber, Antimony, Calamine, Chalk, Coral, Oyster-shells, first cleansed from their impurities, Tutty.

Crabs claws, first broken into small pieces, must be washed with boiling water before they be levigated.

Verdegrieve must be prepared in the same manner.

Where large quantities of the foregoing powders are to be prepared, it is customary, instead of the stone and mallet, to employ hand-mills made for this purpose, consisting of two stones; the uppermost of which turns horizontally on the lower, and has an aperture in the middle, for supplying fresh matter, or of returning that which has already passed, till it be reduced to a proper degree of fineness.

For the levigation of hard bodies, particular care should be taken, whatever kind of instruments be used, that they may be of sufficient hardness, otherwise they will be abraded by the powders. The hematites, a hard iron ore, is most conveniently levigated between two iron planes; for if the common levigating stones be used, the preparation, when finished, will contain almost as much foreign matter from the instrument as the hematites.

It has been customary to moisten several powders in levigation, with rose, balm, and other distilled waters; these, nevertheless, have no advantage above common water, since in the subsequent evaporation they must necessarily exhale, leaving the medicine possessed of no other virtue than what might be equally expected from it when prepared with the cheaper element.

Some few substances, indeed, are more advantageously levigated with spirit of wine than with water. Thus bezoor has the green colour usually expected in this costly preparation considerably improved thereby. A little spirit may be added to the other animal substances, if the weather be very hot, and large quantities of them are prepared at once, to prevent their running into putrefaction; an accident which in those circumstances sometimes happens when they are levigated with water only. Crabs-eyes, which abound with animal gelatinous matter, are particularly liable to this inconvenience.

The caution given above for reducing antimony calamine, and tutty, to the greatest subtilty possible, demands particular attention. The tenderness of the parts to which the two last are usually applied, requires them to be perfectly free from any admixture of gross irritating particles. The first, when not thoroughly comminuted, might not only, by its sharp needle-like spicula, wound the stomach, but likewise answer little valuable purpose as a medicine, proving either an useless load upon the viscera, or at best galloping off without any other sensible effect than an increase of the groser evacuations; while, if reduced to a great degree of fineness, it turns out a medicine of considerable efficacy.

The most successful method of obtaining these powders of the requisite fineness, is, to wash off the finer parts by means of water, and continue levigating the remainder till the whole become fine enough to remain for some time suspended in the fluid; this process is received in the Edinburgh pharmacopoeia, and there directed in the preparation of the following article.

Prepared antimony. E.

Let the antimony be first pounded in an iron mortar, and then levigated on a porphyry with a little water. After this, put it into a large vessel, and pour a quantity of water on it. Let the vessel be repeatedly shaken, that the finer part of the powder may be diffused through the water; the liquor is then to be poured off, and let by till the powder settles. The gross part, which the water would not take up, is to be further levigated, and treated in the same manner.

By this method, which is that commonly practised in the preparation of colours for the painter, powders may be obtained of any required degree of fineness; and without the least mixture of the gross parts, which are always found to remain in them after long continued levigation; all the coarser matter settles at first, and the finer powder continues suspended in the water longer and longer, in proportion to the degree of its fineness. The same process may likewise be advantageously applied to other hard pulverisable bodies of the mineral kingdom, or artificial preparations of them; provided they be not soluble in, or specifically lighter than, water. The animal and absorbent powders, crabs-claws, crabs-eyes, oyster-shells, egg-shells, chalk, pearl, coral, and bezoor, are not well adapted to this treatment; nor indeed do they require it. These substances are readily soluble in acid juices without much commination: if no acid be contained in the first pastages, they are apt to concretize, with the mucous matter usually lodged there, into hard indissoluble masses; the greater degree of fineness they are reduced to, the more they are disposed to form such concretions, and become liable to obstruct the orifices of the small vessels. Prepared calamine. E.

Calamine previously calcined for the use of those who make bras, is to be treated in the same manner as antimony.

Prepared chalk.

Chalk first triturated, and then frequently washed with water, till it imparts to it neither taste nor colour, is to be treated in the same manner as antimony.

As calamine is intended for external application, and often to parts very easily irritated, too much pains cannot be bestowed in reducing it to a fine powder; and the frequent washing of the chalk may have the effect of freeing it from some foreign matters: But with regard to this substance, the after part of the process, if not improper, is, in our opinion at least, unnecessary: and this observation may also be made with respect to the oculi, or more properly lapilli cancriorum, which the Edinburgh college direct to be treated in the same manner.

The preparation of hog's lard and mutton fat. L.

Cut them into pieces, and melt them over a slow fire; then separate them from the membranes by straining.

These articles had formerly a place also among the preparations of the Edinburgh college: But now they introduce them only into their list of the materia medica; as the apothecary will in general find it more for his interest to purchase them thus prepared, than to prepare them for himself: for the process requires to be very cautiously conducted, to prevent the fat from burning or turning black.

The purification of gum ammoniacum. L.

If gum ammoniac do not seem to be pure, boil it in water till it become soft; then squeeze it through a canvas bag, by means of a press. Let it remain at rest till the resinous part subside; then evaporate the water; and toward the end of the evaporation restore the resinous part, mixing it with the gummy.

In the same manner are purified assafetida and such like gum resins.

You may also purify any gum which melts easily, such as Galbanum, by putting it in an ox-bladder, and holding it in boiling water till it be so soft that it can be separated from its impurities by pressing through a coarse linen cloth.

In straining all the gums, care should be taken that the heat be neither great nor long continued; otherwise a considerable portion of the more active volatile matter will be lost; an inconvenience which cannot by any care be wholly avoided. Hence the purer tears, unstrained, are in general to be preferred, for internal use, to the strained gums.

As an additional reason for this preference, we may add, that some of the gum-resins, purified in the common way, by solution in water, expression and evaporation, are not so easily soluble in aqueous menstrua after as before such depuration. On these accounts this process is entirely omitted by the Edinburgh college; and in every case where a gummy resinous substance, before it be taken, is to be dissolved in water, it may be as effectually freed from impurities at the time of solution as by this process. And when it is to be employed in a solid state, care should be taken that the purer parts alone be selected.

The burning of hartshorn. L.

Burn pieces of hartshorn till they become perfectly white; then reduce them to a very fine powder.

The pieces of horn generally employed in this operation are those left after distillation.

In the burning of hartshorn, a strong fire and the free admixture of air are necessary. The potter's furnace was formerly directed for the sake of convenience; but any common furnace or flue will do. If some lighted charcoal be spread on the bottom of the grate, and above this the pieces of the horns are laid, they will be burnt to whiteness, still retaining their original form.

Burnt hartshorn is not now considered as a pure earth, having been found to be a compound of calcareous earth and phosphoric acid. It is the weakest of the animal absorbents, and is difficultly soluble in acids; but whether it be of equal or superior use in diarrhoeas to more powerful absorbents, must be left to observation.

The drying of herbs and flowers.

Let these, spread out lightly, be dried by a gentle heat. L.

Herbs and flowers must be dried by a gentle heat, from a stove or common fire. They must be taken in such quantities at a time, that the process will be speedily finished; for by this means their medical powers are best preserved. The most certain test of this is the perfect preservation of the natural colour: but the leaves of cicuta, and of other plants containing a volatile matter, must be immediately pounded, after being dried, and afterwards kept in a phial with a ground stopper. E.

The directions given by the London college are less explicit, and perhaps less proper, than those of the Edinburgh college: for there can be no doubt of the propriety of drying these substances hastily, by the aid of artificial heat, rather than by the heat of the sun. In the application of artificial heat, the only caution requisite is to avoid burning; and of this a sufficient test is afforded by the preservation of colour. And the direction given with regard to cicuta may perhaps with advantage be followed with most of the other flowers and herbs, afterwards to be exhibited in powder.

The purifying of honey. L.

Melt the honey by the heat of a water bath, and remove the scum.

The intention of this process is to purify the honey from wax, or other droppings that have been united with it by the violence of the press in its separation from the comb, and from meal and such like substances, which are sometimes fraudulently mixed with it. When the honey is rendered liquid and thin by the heat, these lighter matters rise freely to the surface.

This preparation is not so necessary for honey that is to be used as an article of diet, as for that which is employed employed in the preparation of oxymels; hence the Edinburgh college, who have rejected all the oxymels, have omitted this process.

The preparation of millipedes. L. E.

The millipedes are to be inclosed in a thin canvas cloth, and suspended over hot proof-spirit in a close vessel, till they be killed by the steam, and rendered friable.

This is a convenient way of rendering millipedes pulverizable, without endangering any loss of such virtues as they may possess.

The directions given by both colleges are precisely the same, and delivered in almost the same words.

The extraction of pulp. L. E.

Unripe pulpy fruits, and ripe ones if they be dry, are to be boiled in a small quantity of water until they become soft; then press out the pulp through a strong hair-sieve, and afterwards boil it down to the consistence of honey in an earthen vessel, over a gentle fire; taking care to keep the matter continually stirring, to prevent its burning.

The pulp of cassia fistularis is in like manner to be boiled out from the triflled pod, and reduced afterwards to a proper consistence, by evaporating the water.

The pulps of fruits that are both ripe and fresh, are to be pressed out through the sieve, without any previous boiling.

In the extraction of pulps, the direction of both colleges so nearly agree, that it is unnecessary to give a separate translation of each. We may only observe, that the London college, instead of softening the fruits by boiling them in a small quantity of water, direct them to be put in a moist place. This direction, though proper in some cases, is not generally the most suitable.

The drying of squills. L. E.

Let the squill, cleared from its outer skin, be cut transversely into thin slices, and dried with a very gentle heat. When properly managed, the squill is friable, and retains its bitterness and acrimony.

By this method the squill dries much sooner than when its several coats are only separated, as has been usually directed; the internal part is here laid bare, but, in each of the entire coats, it is covered with a thin skin, which impedes the exhalation of the moisture. The root loses in this process four fifths of its original weight; the parts which exhale appear to be merely watery; six grains of the dry root being equivalent to half a dram of the fresh; a circumstance to be particularly regarded in the exhibition of this medicine. In the preceding editions of our pharmacopoeias, a particular caution was given, not to use an iron knife for cutting squills, but one of wood, ivory, or bone; the reason of this caution is said to be, not so much that the squill would receive any ill qualities from the iron; as, that its acid juice, adhering to the knife, might render a wound received by it extremely painful, or even dangerous; but as no danger is to be apprehended from such an accident, the direction appears unnecessary. Dried squills furnish us with a medicine, sometimes advantageously employed as an emetic, often as an expectorant, but still more frequently as a powerful diuretic.

The burning of sponge.

Beat the sponge, after cutting it in pieces; and, when separated from its gritty matter, burn it in a close iron vessel, until it becomes black and friable; afterwards rub it to a very fine powder. L.

Put the sponge, cut into small pieces, and well freed from adhering earthy matters, into a close earthen vessel. Place it on the fire, and let it be stirred frequently till it become black and friable; then reduce it to a powder in a glass or marble mortar. E.

This medicine has been in use for a considerable time, and employed against scrofulous disorders and cutaneous foulnesses, in doses of a scruple and upwards. Its virtues seem to depend on a volatile salt just formed, and combined with its own oil. If the sponge be distilled with a strong heat, it yields a large proportion of that salt in its proper form. The salt is in this preparation so far extricated, that if the burnt sponge be ground in a brass mortar, it corrodes the metal so as to contract a disagreeable taint, and sometimes an emetic quality.

Bees, earthworms, and other animal substances, have by some been prepared in the same manner, and recommended in different diseases; but as these substances fall much short of sponge in the quantity of volatile salt producible from them by fire, they are probably inferior also in medicinal efficacy. Of all the animal matters that have been tried, raw silk is the only one which exceeds or equals sponge, in the produce of salt.

A good deal of address is requisite for managing this process in perfection. The sponge should be cut small, and beaten for some time in a mortar, that all the stony matters may be got out, which compared with the weight of the sponge when prepared, will sometimes amount to a considerable quantity. The burning should be discontinued as soon as the matter is become thoroughly black. If the quantity put into the vessel at once be large, the outside will be sufficiently burnt before the inside be affected; and the volatile salt of the former will in part escape, before that in the latter is begun to be formed. The best method of avoiding this inconvenience seems to be, to keep the sponge continually stirring, in such a machine as is used for the roasting of coffee.

And from this circumstance the iron vessel directed by the London college is preferable to the earthen one directed by that of Edinburgh. But the pounding in a glass or marble mortar, directed by the latter, is a necessary caution which the former college have omitted.

The purification of storax. L.

Dissolve the storax in rectified spirit of wine, and strain the solution; afterwards reduce it to a proper thickness with a gentle heat.

Storax was formerly directed to be purified by means of water; hence it was styled hyracis collatio; but the method now adopted is much preferable, for the active parts. parts of the storax totally dissolve in spirit of wine, the impurities alone being left. And as these active parts do not rise in distillation, the spirit may be again recovered by distillation.

Purified filings of iron. E.

Apply a magnet to a sieve placed on filings of iron, so that the filings may be attracted upwards through the sieve.

Rust of iron, commonly called shavings of iron, prepared. E.

Set purified filings of iron in a moist place, that they may turn to rust, which is to be ground into an impalpable powder.

The cleansing of iron filings by means of a magnet is very tedious, and does not answer so well as might be expected; for if they are rusty, they will not be attracted by it, or not sufficiently; nor will they by this means be entirely freed from brass, copper, or other metallic substances which may adhere to them. It appears from the experiments of Henckel, that if iron be mixed by fusion with even its own weight of any of the other metals, regulus of antimony alone excepted, the compound will be vigorously attracted by the lodestone. The rust of iron is to be procured at a moderate rate from the dealers in iron, free from any impurities except such as may be washed off by water.

The rust of iron is by some preferred as a medicine to the calces or croci made by a strong fire. Hoffman relates, that he has frequently given it with remarkable success in obstinate chlorotic cases accompanied with excessive headaches and other violent symptoms; and that he usually joined with it pimpinella, arum root, and salt of tartar, with a little cinnamon and sugar. The dose is from four or five grains to twenty or thirty; some have gone as far as a dram; but all the preparations of this metal answer best in small doses, which should rather be often repeated than enlarged.

Scales of iron purified. E.

Let the scales of iron, which may be had at the anvils of the workmen, be purified by the magnet; for the magnet only attracts the smaller and purer parts, leaving the more thick and impure behind.

This is perhaps of all the forms the most eligible for obtaining the pure matter in such a divided state as to render it easily acted on by different menstrua; and the mode of purification here proposed is not only very effectual, but also very easily put into practice.

The extraction of mucilage. Gen.

Boil the gums or mucilaginous seeds in a sufficient quantity of water till it becomes viscid, nearly resembling the white of an egg; and then strain it by pressure through a linen cloth.

By this means vegetable mucilage may be easily obtained from many different substances in its pure state. And although this process is not directed in our pharmacopoeias, yet we think that it might with advantage be adopted.

Conserves are compositions of recent vegetable matters and sugar, beaten together into an uniform mass.

This management is introduced for preserving certain simples, undried, in an agreeable form, with as little alteration as possible in their native virtues; and to some subjects it is very advantageously applied. Vegetables, whose virtues are lost or destroyed by drying, may in this form be kept uninjured for a length of time; for, by carefully securing the mouth of the containing vessel, the alteration, as well as dissipation, of their active principles, is generally prevented; and the sugar preserves them from the corruption which juicy vegetables would otherwise undergo. There are, however, sundry vegetables whose virtues are impaired by this treatment. Mucilaginous substances by long lying with sugar, become less glutinous; and astringents become sensibly softer on the palate. Many of the fragrant flowers are of so tender and delicate a texture, as almost entirely to lose their peculiar qualities on being beaten or bruised.

In general, it is obvious, that in this form, on account of the large admixture of sugar, substances of considerable activity can alone be taken to advantage as medicines. And, indeed, conserves are at present considered chiefly as auxiliaries to medicines of greater efficacy, or as intermedia for joining them together. They are very convenient for reducing into boluses or pills the more ponderous powders, as mercurius dulcis, the calces of iron, and other mineral preparations; which, with liquid or less consistent matters, as syrups, will not cohere.

The shops were formerly encumbered with many conserves altogether insignificant; the few now retained have in general either an agreeable flavour to recommend them, or are capable of answering some useful purposes as medicines. Their common dose is the bulk of a nutmeg, or as much as can be taken up at once or twice upon the point of a knife. There is in general no great danger of exceeding in this particular.

Conserves of wood sorrel; sea wormwood; the red rose; the outer rind of the Seville orange. L.

Pluck the leaves from the stalks, the unblown petals from the cups, taking off the heels. Take off the outer rind of the oranges by a grater; then beat each of them with a wooden pestle in a marble mortar, first by themselves, afterwards with three times their weight of double refined sugar, until they be mixed.

Conserves of the fresh leaves of mint; red roses not blown; the outer rind of Seville oranges rasped off by a grater. E.

These are directed to be prepared with triple their weight of sugar in the same manner as the conserves of the London college. The sugar should be pounded by itself, and passed through a sieve before it be mixed with the vegetable mass; for without this it cannot cannot be properly incorporated. Rose buds, and some other vegetables, are prepared for mixing with sugar by a small wooden mill contrived for that purpose.

In the same manner conserves may be prepared from many other vegetables. But besides the conserves for which general directions are given, there are others, for which, either on account of the particular mode of preparation, or of the proportion, our pharmacopoeias have thought it necessary to give particular directions. But before taking notice of these, it is necessary to mention the medical properties of the conserves above enumerated.

Conserve of the leaves of wood-sorrel. L.

This is a very elegant and grateful conserve; in taste it is lightly acidulous, with a peculiar flavour, which some compare to that of green-tea. It is taken occasionally for quenching thirst, and cooling the mouth and fauces, in distempers where the heat of the body is much increased.

Conserve of the tops of sea wormwood. L.

The conserve of wormwood has been celebrated in dropsies: Matthiolus relates, that several persons were cured by it of that distemper without the assistance of any other medicine. Where the disorder indeed proceeds from a simple laxity or flaccidity of the solids, the continued use of this medicine may be of some service; as it appears to be an elegant mild corroborant. It is directed to be given in the dose of half an ounce about three hours before meals.

Conserve of the buds of red roses. L. E.

This is a very agreeable and useful conserve. A dram or two dissolved in warm milk are frequently given as a light astringent, in weakness of the stomach, and likewise in coughs and phthisical complaints. In the German ephemerides, examples are related of very dangerous phthisis cured by the continued use of this medicine: In one of these cases, twenty pounds of the conserve were taken in the space of a month; and in another, upwards of thirty. Riverius mentions several other instances of this kind. There is, however, much room for fallacy in such observations; as phthisis has not at all times been accurately distinguished from obstinate catarrhs, and some other affections; the antiseptic property of the sugar may perhaps have some share in the effect.

Conserve of the yellow rind of Seville orange-peel. L. E.

This conserve is a very elegant one, containing all the virtues of the peel in a form sufficiently agreeable, both with regard to the dose and the convenience of taking. It is a pleasant warm stomachic; and with this intention is frequently used.

Conserve of the leaves of spearmint. E.

The conserve of mint retains the taste and virtues of the herb. It is given in weaknesses of the stomach and retchings to vomit; and frequently does service in some cases of this kind, where the warmer and more active preparations of mint would be less proper.

Conserve of arum.

Take of the fresh root of arum bruised, half a pound; double refined sugar, a pound and a half. Beat them together in a mortar.

The root of arum, in its recent state, is a substance of great activity; but this activity is almost entirely lost on drying. Hence the compound powder which had formerly a place in our pharmacopoeias is now rejected. And as neither water nor spirit extract its activity, this conserve is perhaps the best form in which it can be preserved in our shops. It may be given to adults in doses of a dram.

Conserve of hips. L.

Take of pulp of ripe hips one pound; double refined sugar, powdered, twenty ounces. Mix them into a conserve.

The conserve of hips is of some esteem as a soft cooling astringent; three or four drams or more are given at a time, in bilious fluxes, sharpness of urine, and hot indispositions of the stomach: A good deal of care is requisite on the part of the apothecary in making this conserve: the pulp is apt to carry with it some of the prickly fibres, with which the inside of the fruit is lined; if these be retained in the conserve, they will irritate the stomach, so as to occasion vomiting.

Conserve of floes. L. E.

Put the floes in water upon the fire that they may soften, taking care that they be not broken; then, the floes being taken out of the water, press out the pulp, and mix it with three times its weight of double refined sugar into a conserve.

This preparation is a gentle astringent, and may be given as such in the dose of two or three drams. The degree of its astringency will vary according to the maturity of the floes, and the length of time for which the conserve has been kept.

Conserve of squills.

Take of fresh squills, one ounce; double-refined sugar, five ounces. Beat them together in a mortar into a conserve.

This conserve is directed to be prepared in a small quantity, to guard against its varying in strength. It may be given to adults from half a dram to two scruples, especially when fresh.

But the conserve of squills is a more uncertain and less agreeable mode of exhibiting this article, than the powder of the dried root, particularly when made into pills, or given in the form of bolus with any other conserve.

Conserve of chervil. Suec.

Take of fresh leaves of chervil, double-refined sugar, each equal parts. Beat them together into a conserve.

Chervil has by some been extolled as an useful diuretic; and this is perhaps one of the most pleasant forms under which it can be exhibited.

Conserve of millipedes. Brun.

Take of live millipedes, one pound; double-refined sugar, two pounds and a half. Beat them together into a conserve.

If the millipedes possess those virtues which some have alleged, this is perhaps one of the best forms under To each pound of the conserve of roses add two drams of the diluted vitriolic acid.

This may be in some cases an useful means of increasing somewhat the astringency of the conserve of roses; but for the purposes for which the vitriolic acid is in general employed, the quantity that can thus be introduced is too inconsiderable to be of much service.

**CHAP. III Of Juices.**

Juices are obtained from the succulent parts of plants, by including them, after being properly cut, bruised, &c. in a hair bag, and pressing them, between wooden cheeks, in the common screw-pres, as long as any liquor exudes.

The harder fruits require to be previously well beaten or ground; but herbs are to be only moderately bruised, for if these are over-bruised, a large quantity of the herbaceous matter will be forced out along with the juice. Hempen or woollen bags are apt to communicate a disagreeable flavour; the threads of these likewise swell in proportion as they imbibe moisture, so as in great measure to prevent the free percolation of the juice.

The fluids thus extracted from succulent fruits, both of the acid and sweet kind, from most of the acid herbs, as scurvy-grafts and water-cresses, from the acid herbs, as forrel and wood forrel, from the aperient lactescent plants, as dandelion and hawkweed, and from sundry other vegetables, contain great part of the peculiar taste and virtues of the respective subjects. The juices, on the other hand, extracted from most of the aromatic herbs as those of mint and the fragrant Turkey balm, commonly called balm of Gilead, have scarcely anything of the flavour of the plants, and seem to differ little from decoctions of them made in water boiled till the volatile odorous parts have been dissipated.

Many of the odoriferous flowers, as the lily, violet, hyacinth, not only impart nothing of their fragrance to their juice, but have it totally destroyed by the previous bruising. From want of sufficient attention to these particulars, practitioners have been frequently deceived in the effects of preparations of this class: juice of mint has been often prescribed as a stomachic, tho' it wants those qualities by which mint itself and its other preparations operate.

The juices, thus forcibly pressed out from plants, differ from those which flow spontaneously, or from incisions; these last consisting chiefly of such fluids as are not diffused through the whole substance of the vegetable subject, but elaborated in distinct vessels, or secreted into particular receptacles. From poppy heads, slightly wounded, there issues a thick milky liquor, which dries by a moderate warmth into opium; whilst the juice obtained from them by pressure is of a dark-green colour, and far weaker virtue.

Juices newly expressed are generally thick, viscid, and very impure: By colature, a quantity of gross matter is separated, the juice becomes thinner, limpid, and better fitted for medicinal purposes, though as yet not entirely pure: on standing, it becomes again turbid, and apt to run into a fermentative or putrefactive state. Clarification with whites of eggs renders the juices more perfectly fine; but there are few that will bear this treatment without a manifest injury to their flavour, taste, and virtue.

The most effectual method of purifying and preserving these liquors, is to let the strained juices stand in a cool place till they have deposited their grossest feces, and then gently pass them several times through a fine strainer till perfectly clear; when about a fourth part of their weight of good spirit of wine may be added, and the whole suffered to stand as before: a fresh sediment will now be deposited, from which the liquor is to be poured off, strained again, and put into small bottles which have been washed with spirit and dried. A little oil is to be poured on the surface, so as very nearly to fill the bottles, and the mouths closed with leather, paper, or stopped with straw, as the flasks in which Florence wine is brought to us: this serves to keep out dust, and suffers the air, which in processes of time arises from all vegetable liquors, to escape; which air would otherwise endanger the bursting of the bottles; or, being imbibed afresh, render their contents vapid and foul. The bottles are to be kept on the bottom of a good cellar or vault, placed up to the necks in sand. By this method some juices may be preserved for a year or two; and others for a much longer time.

It has already been observed, that there are great differences in juices, in regard to their being accompanied in the expression with the virtues of the subjects. There are equal differences in regard to their preserving those virtues, and this independently of the volatility of the active matter, or its disposition to exhale. Even the volatile virtue of scurvy-grafts may by the above method be preserved almost entire in its juice for a considerable time: while the active parts of the juice of the wild cucumber quickly separate and settle to the bottom, leaving the fluid part inert. Juices of arum root, iris root, bryony root, and sundry other vegetables, throw off in like manner their medicinal parts to the bottom.

**Compound juice of scurvy-grafts.**

Take of the juice of garden scurvy-grafts two pints; brook lime and water-cresses, of each one pint; Seville oranges, twenty ounces by measure. Mix them, and, after the feces have subsided, pour off the liquor, or strain it. L.

Take of juice of garden scurvy-grafts, water-cresses, both expressed from the fresh herbs, Seville oranges, of each two pounds; spirituous nutmeg-water, half a pound. Mix them and let them stand till the feces have subsided, then pour off the clear liquor. E.

By this formula the Edinburgh college have rejected the brook lime and the sugar of their former editions. The sugar was certainly a very improper addition; for though it may preserve dry vegetable matters, yet when added to juices largely impregnated with watery and mucilaginous matter, it would no doubt furnish that very principle most favourable to the production of the vinous fermentation. For the compound horseradish water they have substituted the spirituous water of nutmegs: Besides that, this water has the same property of of preserving the juices from fermentation; it is also much more agreeable to the palate, and will make the juices fit easier on the stomach.

The London college have retained nearly their former formula, giving it only a more proper name.

Both these compositions are of considerable use for the purposes expressed in the title; the orange juice is an excellent assistant to the scurvy-grass and other acid antiscorbutics; which, when thus mixed, have been found from experience to produce much better effects than when employed by themselves. These juices may be taken from an ounce or two to a quarter of a pint, two or three times a day; they generally increase the urinary secretion, and sometimes induce a laxative habit. Preserved with the cautions above-mentioned, they will keep good for a considerable time; though, whatever care be taken, they are found to answer better when fresh; and from the difficulty of preserving them so, they have of late been very much laid aside, especially since we have been provided with more convenient and useful remedies.

**Inspissated Juices.**

When vegetable juices, or watery or spirituous decoctions or infusions, are exposed to a continued heat, the fluid gradually evaporating, carries off with it such volatile matters as it was impregnated with, and leaves the more fixed united together into one mass. The mass which remains from the evaporation of the expressed juice of a plant is called *inspissated juice*; from watery decoctions or infusions, an *extract*; from spirituous tinctures, a *resin*, or *essential extract*. The term *extract* is frequently used also as a general appellation of all the three kinds. Inspissated juices and watery decoctions, particularly the former, when evaporated no further than to the consistence of oil or honey, are called *robs*; and spirituous tinctures, reduced to a like consistence, are called *balsams*.

What relates to the expression of juices has already been delivered, with the most effectual means of preserving them in their liquid state, and a general account of what substances do or do not give out their virtues with their juices. In the inspissation of juices, there is further to be considered the volatility or fixity of their medicinal parts: if a plant loses its virtue, or part of its virtue, in being dried, it is obvious that the juice must lose as much in being inspissated to dryness, how gentle soever the heat be with which the inspissation is performed. It is likewise to be observed, that the medicinal parts of some juices are kept in a state of perfect solution by the watery fluid, so as to be completely retained by it after the liquor has been made fine by settling, straining, or other means; while the medicinal parts of others, not dissoluble by watery menstrua, are only diffused through the liquor in the same manner as the feculencies are, and separate along with these on standing.

**Inspissated juice of the elder-berry.** L.

Take of expressed and depurated juice of elder-berries two pints; inspissate it in a water bath, saturated with sea-salt.

**Inspissated juice,** commonly called *rob of elder-berries.* E.

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Take of juice of ripe elder-berries, five pounds; purest sugar, one pound. Evaporate with a gentle heat to the consistence of pretty thick honey.

This preparation, made with or without sugar, keeps well, and proves a medicine of considerable importance as an aperient, generally promoting the natural excretions by stool, urine, or sweat. The dose is from a dram or two to an ounce or more. A spoonful, diluted with water, is usually taken in common colds at bed-time.

**Inspissated juice of wolfsbane.** E.

Bruise the fresh leaves of aconitum; and including them in a hempen bag, strongly compress them in a press, so that they may give out their juice: let the juice be evaporated in open vessels in a water-bath, to the consistence of pretty thick honey: An empyreuma is to be avoided by constantly stirring the mixture towards the end of the process. After the matter has become cold, let it be put up in glazed earthen vessels, and moistened with rectified spirit-of-wine.

In the same manner are prepared inspissated juices of belladonna or deadly nightshade, and hyoscyamus or henbane.

In these inspissated juices, the active parts of the plant are obtained in a concentrated state, and in a condition which admits of preparation for a considerable length of time. They furnish, therefore, a convenient form for exhibiting these articles which, in the practice of medicine, are perhaps more frequently used in the state of inspissated juice than any other. This is particularly the case with the hyoscyamus, which may often be advantageously employed when opium is indicated, but disagrees with the patient. But aconite and belladonna may in general, with greater advantage, be exhibited under the form of powder made from the dried leaves.

It is very remarkable that the London college have given no place to these articles. We cannot however help thinking, that their pharmacopoeia would be enriched by introducing not only the articles themselves, but likewise these preparations, especially as they are not unfrequently prescribed by British practitioners.

**Inspissated juice of hemlock.** E.

Having expressed the juice of the leaves and stalks of hemlock when flowering, in the same manner as directed for that of the aconitum, evaporate it to the consistence of pretty thin honey; when it is cooled, add of the powder of the dried leaves of the plant as much as to make it into a mass fit for forming pills. Care, however, is to be taken, that the evaporation proceed only to such length, that as much of the powder can be mixed with the inspissated juice as shall make up about a fifth part of the whole mass.

A preparation similar to this was published at Vienna by Dr Stoerk, who recommends it as an efficacious resolvent in many obstinate disorders, where the common remedies avail nothing. He observes, that small doses should always be begun with, as two grains, made into a pill twice a-day; and that by gradually increasing increasing the dose, it may be given to two, three, or even four drams a day, and continued in such quantities for several weeks; that it may be used in safety in infancy, old age, and pregnancy; that it neither accelerates nor disturbs the circulation; neither heats, nor cools, nor affects the animal functions; that it increases the secretions, and renders the mouth moist; seldom purges; very rarely vomits; sometimes augments perspiration; often produces a copious discharge of viscid urine; but in many patients does not increase any of the sensible evacuations; that it removes obstructions and their consequences; relieves rheumatic pains, though of long continuance; dissolves febrile tumors, both internal and external; and cures dropsies and consumptions proceeding from scirrhoussities; that it often dissolves catarrhs, or stops their progress, and has sometimes removed the gutta serena; that inwetrate cutaneous eruptions, scald heads, malignant ulcers, cancers, the malignant flor albus and gonorrhea of long standing, obstinate remains of the venereal disease, and caries of the bones, generally yield to it; that for the most part it is necessary to continue this medicine for a considerable time before the cure be effected, or much benefit perceived from it; that in some cases it failed of giving any relief; that he met with some persons who could not bear its effects; and that consequently there must be some latent difference in the habit, the diagnostic signs of which are at present unknown; that though it is by no means infallible any more than other medicines, yet the great number of deplorable cases that have been happily cured by it, is sufficient to recommend it to further trials. The efficacy of this medicine is confirmed by many eminent practitioners abroad; though the trials hitherto made of it in this country have not been attended with much success. Somewhat, perhaps, may depend on the time of the plant's being gathered, and the manner of the preparation of the extract. Dr Stoerk himself takes notice of some mistakes committed in this respect: some have left the herb in a heap for several days, whence part of it withered, past rotted, and the juice became thick and mucilaginous; others have taken a very large quantity of the juice, and boiled it down in copper vessels with a great heat; by which means a strong fetor was diffused to a considerable distance, and the most efficacious parts dissipated: others, with officious care, have clarified the juice, and thus obtained a black tenacious extract, retaining but a small degree of the specific smell of the plant. The extract, duly prepared, according to the above prescription, is of a greenish brown colour, and a very agreeable smell, like that of mice. But though there be reason to believe that much of the extract used here had been ill prepared, we can by no means admit that its general inefficacy was owing to this cause; for though there are not many instances of its discovering any valuable medicinal powers, there are several of its having activity enough, even in small doses, to produce alarming symptoms.

Modern practice, however, seems to hold a middle place; being neither influenced by the extravagant encomiums of Dr Stoerk, nor frightened by the wary suspicions of Dr Lewis. The inspissated juice of the hemlock is accordingly given with freedom in a great variety of complaints, without our experiencing the wonderful effects ascribed to it by the former, or the baneful consequences dreaded by the latter. Like other preparations of this valuable herb, it is no doubt a very useful addition to our pharmacopoeia; nor does its use seem to be more hazardous than that of opium and some other narcotics.

The London college direct the inspissated juice of cicuta to be prepared in the same manner as that of the elder-berry, and without the addition of any of the powder. This is the most pure extract; and the powder may easily be occasionally added. They direct the cicuta to be collected as soon as the flowers appear: And at that time the leaves are most fully impregnated with their active powers.

**Inspissated juice of black currants. L.**

**Inspissated juice of lemons. L.**

These two the London college also direct to be prepared in the same manner with the elder-berry juice. And under this form the agreeable and useful acid of these vegetables, in a concentrated state, may be preserved for a considerable length of time.

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**CHAP. IV. Extracts and Resins.**

**Observations on Extracts with Water.**

These extracts are prepared by boiling the subject in water, and evaporating the strained decoction to a thick consistence.

This process affords us some of the more active parts of the plants, free from the useless indissoluble earthy matter, which makes the largest share of their bulk. There is a great difference in vegetable substances, with regard to their fitness for this operation; some yielding to it all its virtues, and others scarce any. Those parts in which the sweet, glutinous, emollient, cooling, bitter, astringent virtues reside, are for the most part totally extracted by the boiling water, and remain almost entire on evaporating it: whilst those which contain the peculiar odour, flavour, and aromatic quality, are either not extracted at all, or exhale along with the menstruum. Thus gentian root, which is almost purely bitter, yields an extract possessing in a small volume the whole taste and virtues of the root.—Wormwood, which has a degree of warmth and strong flavour joined to the bitter, loses the two first in the evaporation, and gives an extract not greatly different from the foregoing: the aromatic quality of cinnamon is dissipated by this treatment, its astringency remaining; while an extract made from the flowers of lavender and rosemary discovers nothing either of the taste, smell, or virtues of the flowers.

**General Rules for making Extracts with Water.**

1. It is indifferent, with regard to the medicine, whether the subject be used fresh or dry; since nothing that can be preferred in this process will be lost by drying. With regard to the facility of extraction, there is a very considerable difference; vegetables in general giving out their virtues more readily when moderately dried than when fresh.

2. Very 2. Very compact dry substances should be reduced into exceeding small parts, previous to the affusion of the menstruum.

3. The quantity of water ought to be no greater than is necessary for extracting the virtues of the subject. A difference herein will sometimes occasion a variation in the quality of the product; the larger the quantity of liquor, the longer time will be requisite for evaporating it, and consequently the more volatile parts of the subject will be diffused. A long-continued heat likewise makes a considerable alteration in the matter which is not volatile. Sweet substances, by long boiling with water, become nauseous; and the drastic purgatives lose their virulence, though without any remarkable separation of their parts.

4. The decoctions are to be depurated by colature; and afterwards suffered to stand for a day or two, when a considerable quantity of sediment is usually found at the bottom. If the liquor poured off clear be boiled down a little, and afterwards suffered to cool again, it will deposite a fresh sediment from which it may be decanted before you proceed to finish the evaporation. The decoctions of very resinous substances do not require this treatment, and are rather injured by it; the resin subsiding along with the inactive dregs.

5. The evaporation is most conveniently performed in broad shallow vessels; the larger the surface of the liquor, the sooner will the aqueous parts exhale: This effect may likewise be promoted by agitation.

6. When the matter begins to grow thick, great care is necessary to prevent its burning. This accident, almost unavoidable if the quantity be large, and the fire applied as usual under the evaporating pan, may be effectually prevented against, by carrying on the inspissation after the common manner, no farther than to the consistence of a syrup, when the matter is to be poured into shallow tin or earthen pans, and placed in an oven, with its door open, moderately heated; which acting uniformly on every part of the liquid, will soon reduce it to any degree of consistence required. This may likewise be more securely done, by setting the evaporating vessel in boiling water, but the evaporation is in this way very tedious.

Observations on Extracts with Rectified Spirit.

Rectified spirit of wine dissolves the essential oils and resins of vegetables, and does not readily carry off the oil in its exhalation; the heat sufficient to exhale pure spirit being much less than that in which water evaporates to any considerable degree, or most essential oils distil. Hence a resinous or spirituous extract of wormwood, contrary to that made with water, contains the warmth and flavour, as well as bitters, of the herb; one made from cinnamon possesses its aromatic virtue, as well as its astringency; and one from lavender and rosemary flowers, retains great part of their flavour and virtues; the volatile parts, which are carried off by water in its evaporation, being left behind by the spirit.

The spirit employed for this purpose should be perfectly free from any ill flavour, which would be communicated in part to the preparation; and from any admixture of phlegm or water, which would not only vary its dissolving power, but likewise, evaporating towards the end of the inspissation, would promote the diffusion of the volatile parts of the subject. Hence, also, the subject itself ought always to be dry: those substances which lose their virtue by drying, lose it equally on being submitted to this treatment with the purest spirit.

The inspissation should be performed from the beginning, in the gentle heat of a water bath. It is not needful to suffer the spirit to evaporate in the air; greatest part of it may be recovered by collecting the vapour in common distilling vessels. If the distilled spirit be found to have brought over any flavour from the subject, it may be advantageously referred for the same purposes again.

It is observable, that though rectified spirit be the proper menstruum of the pure volatile oils, and of the groser resinous matter of vegetables, and water of the mucilaginous and saline; yet these principles are, in almost all plants, so intimately combined together, that whichever of these liquors is applied at first, it will take up a portion of what is directly soluble only in the other. Hence sundry vegetables, extremely resinous, and whose virtues consist chiefly in their resin, afford nevertheless very useful extracts with water, though not equal to those which may be obtained by a prudent application of spirit. Hence also the extracts made from most vegetables by pure spirit, are not mere resins; a part of the gummy matter, if the subject contained any such, is taken up along with the resin; an admixture of great advantage to it in a medicinal view. The spirituous extracts of several vegetable substances, as mint leaves, rhubarb, saffron, dissolve in water as well as in spirit.

Pure resins are prepared by mixing, with spirituous tincture of very resinous vegetables, a quantity of water. The resin, incapable of remaining dissolved in the watery liquor, separates and falls to the bottom; leaving in the menstruum such other principles of the plant as the spirit might have extracted at first along with it.

Observations on Extracts with Spirit and Water.

There are sundry vegetables, particularly those of a resinous nature, which are treated to better advantage with a mixture of water and spirit, than with either of them singly. The virtues of resinous woods, barks, and roots, may indeed be in great part extracted by long boiling in fresh portions of water; but at the same time they suffer a considerable injury from the continued heat necessary for the extraction, and for the subsequent evaporation of so large a quantity of the fluid. Rectified spirit of wine is not liable to this inconvenience; but the extracts obtained by it from the substances here intended, being almost purely resinous, are less adapted to general use than those in which the resin is divided by an admixture of the gummy matter, of which water is the direct menstruum.

There are two ways of obtaining these compound or gummy-resinous extracts: one, by using proof-spirit, that is, a mixture of about equal parts of spirit and water, for the menstruum; the other, by digesting the subject first in pure spirit and then in water, and afterwards uniting into one mass the parts which the two menstrua have separately extracted. In some cases, where a sufficiency of gummy matter is wanting in the subject, it may be artificially supplied, by insufflating the spirituous tincture to the consistence of a balsam, then thoroughly mixing with it a thick solution of any simple gum, as mucilage of gum-arabic, and drying the compound with a gentle heat. By this method are obtained elegant gummy-resins, extemporaneously miscible with water into milky liquors.

Observations on extracts by long digestion.

It has been observed, that the virtues of vegetable decoctions are altered by long boiling. Decoctions or infusions of drastic vegetables, by long continued boiling or digestion, lose more and more of their virulence; and at the same time deposit more and more of a gross sediment, resulting probably from the decomposition of their active parts. On this foundation it has been attempted to obtain safe and mild preparations from sundry virulent drugs; and some of the chemists have strongly recommended the process, though without specifying, or giving any intimation of, the continuance of boiling requisite for producing the due mildness in different subjects. M. Beaumé, in his Elements de Pharmacie, lately published, has given a particular account of an extract of opium prepared on this principle; of which extract, as it is alleged to be very useful in practice, it may not be improper to give a short description: And this we shall accordingly subjoin to our account of the opium purificatum of the London college.

Observations on particular extracts.

Extract of chamomile, broom tops, gentian, liquorice, black hellebore, rue, sawin. L.

Boil the article in distilled water, press out the decoction, strain it, and let it apart that the feces may subside; then boil it again in a water-bath saturated with sea-salt to a consistence proper for making pills.

The same kind of bath is to be used in the preparation of all the extracts, that the evaporation may be properly performed.

Extract of gentian. E.

Take of gentian root as much as you please. Having cut and bruised it, pour upon it four times its quantity of water. Boil to the consumption of one half of the liquor; and strongly expressing it, strain. Evaporate the decoction to the consistence of thick honey in vessels exposed to the vapour of hot water.

In preparing this and every other extract, it is necessary to keep up a constant stirring towards the end of the process, in order to prevent an empyreuma, and that the extract may be of an uniform consistence, and free of clots.

In the same manner are prepared,

Extract of the roots of black hellebore; leaves of the pulsatilla nigricans; leaves of rue; leaves of white poppies; imperfectly ripe seeds of hemlock.

All the above extracts contain the virtues of the vegetable in a state of tolerable perfection.

The extract of chamomile loses in its formation the specific flavour of the plant; but it is said to furnish a bitter remarkably antifeptic, and to be given with advantage in different stomach ailments to the extent of a scruple or two, either by itself, or in conjunction with other remedies. The extract of broom tops is chiefly employed in hydropic cases; and when taken to the quantity of about a dram, is said to operate as a powerful diuretic.

The mode of preparing these extracts directed by the London and Edinburgh colleges is not essentially different: but some advantage will arise from employing the distilled water directed by the former; and the directions given by the latter with regard to the quantity of water to be used, and the degree of boiling to be employed before expression, are not without some use.

The extract is the only preparation of the pulsatilla nigricans, and it seems sufficiently well suited to be brought into this form. The extract of the white poppy-heads is not perhaps superior in any respect to opium; but to those who may think otherwise, it is convenient to prefer them in this form for preparing the syrup occasionally. The seeds of hemlock have by some been thought stronger, or at least that they produce giddiness sooner, than the leaves; but this extract has not hitherto come into general use.

Compound extract of coloquintida. L.

Take of pith of coloquintida, cut small, six drams; socotrine aloes, powdered, an ounce and a half; scammony, powdered, half an ounce; smaller cardamom seeds, husked and powdered, one dram; proof spirit, one pint. Digest the coloquintida in the spirit, with a gentle heat, during four days. To the expressed tincture add the aloes and scammony; when these are dissolved, distil off the spirit, so that what remains may be of a consistence proper for making pills, adding the seeds towards the end of the process.

This composition answers very effectually as a cathartic, so as to be relied on in cases where the patient's life depends on that effect taking place: the dose is from fifteen grains to half a dram. The proof spirit is a very proper menstruum for the purgative materials; dissolving nearly the whole substance of the aloes and scammony, except the impurities; and extracting from the colocynth, not only the irritating resin, but great part of the gummy matter. In the former pharmacopoeias three spices were employed in this composition, cinnamon, mace, and cloves: the cardamom seeds, now introduced, are preferable, on account of their aromatic matter being of a less volatile nature; though a considerable part of the flavour, even of these, is dissipated during the evaporation of the phlegmatic part of the proof-spirit.

Elaterium. L.

Slit ripe wild cucumbers, and pass the juice, very lightly lightly pressed, through a fine hair sieve, into a glass vessel; then set it by for some hours until the thicker part has subsided. Pour off the thinner part swimming at the top, and separate the rest by filtering; cover the thicker part, which remains after filtration, with a linen cloth, and dry it with a gentle heat.

What happens in part in preparing the extract of hemlock, happens in this preparation completely, viz. the spontaneous separation of the medicinal matter of the juice on standing for a little time: and the case is the same with the juices of several other vegetables, as those of arum root, iris root, and bryony root. Preparations of this kind have been commonly called fuscule. The filtration above directed, for draining off such part of the watery fluid as cannot be separated by decantation, is not the common filtration through paper, for this does not succeed here: the grosser parts of the juice, falling to the bottom, form a viscid cake upon the paper, which the liquid cannot pass through. The separation is to be attempted in another manner, so as to drain the fluid from the top: this is effected by placing one end of some moistened strips of woollen cloth, skains of cotton, or the like, in the juice, and laying the other end over the edge of the vessel, so as to hang down lower than the surface of the liquor: by this management the separation succeeds in perfection.

Elaterium is a very violent hydragogue cathartic. In general, previous to its operation, it excites considerable sickness at the stomach, and not unfrequently it produces severe vomiting. Hence it is seldom employed till other remedies have been tried in vain. But in some instances of ascites it will produce a complete evacuation of water where other cathartics have had no effect. Two or three grains are in general a sufficient dose. And perhaps the best mode of exhibiting it is by giving it only to the extent of half a grain at a time, and repeating that dose every hour till it begins to operate.

Extract of logwood. L.

Take of shavings of logwood, one pound. Boil it four times, or oftener, in a gallon of distilled water, to one half; then, all the liquors being mixed and strained, boil them down to a proper consistence.

The extract of logwood has been used for a considerable time in some of our hospitals. It has an agreeable sweet taste, with some degree of astringency; and hence becomes serviceable in diarrhoeas, for moderately constringing the intestines and orifices of the smaller vessels: it may be given from a scruple to half a dram, and repeated five or six times a-day with advantage. During the use of this medicine, the stools are frequently tinged red by it, which has occasioned some to be alarmed as if the colour proceeded from blood: the practitioner therefore ought to caution the patient against any surprise of this kind.

The active parts of the logwood are difficultly extracted by means of water alone: hence the Edinburgh college call in the aid of spirit of wine, directing this extract to be prepared in the same manner as that of jalap, afterwards to be mentioned. And of the two modes, we are inclined to consider the latter as intitled to the preference.

Extract of Peruvian bark. L.

Take of Peruvian bark, coarsely powdered, one pound; distilled water, 12 pints. Boil it for one or two hours, and pour off the liquor, which, while hot, will be red and pellucid; but, as it grows cold, will become yellow and turbid. The same quantity of water being again poured on, boil the bark as before, and repeat this boiling until the liquor, being cold, remains clear. Then reduce all these liquors, mixed together and strained, to a proper thickness, by evaporation.

This extract must be prepared under two forms; one soft, and fit for making pills; the other hard, that it may be reducible to a powder.

Extract of Peruvian bark with the resin. L.

Take of Peruvian bark, reduced to coarse powder, one pound; rectified spirit of wine, four pints. Digest it for four days, and pour off the tincture; boil the residuum in 10 pints of distilled water to two; then strain the tincture and decoction separately, evaporating the water from the decoction, and distilling off the spirit from the tincture, until each begins to be thickened. Lastly, mix the resinous with the aqueous extract, and make the mass fit for forming into pills.

Extract of Peruvian bark. E.

The Edinburgh college, who have not given a place to any pure watery extract of the bark, direct their extract of this medicine to be prepared in the same manner as their extract of jalap, that is, almost precisely in the same manner as the extract with resin of the London college. It is, however, we think with propriety, that the London college have given a place to both extracts; for neither is without its use.

Peruvian bark is a resinous drug; the resin melts out by the heat, but is not perfectly dissolved by the water: hence, in cooling, it separates, renders the liquor turbid, and in part falls to the bottom, as appears manifestly upon examining the sediment by spirit of wine. This extract might be made to better advantage by the assistance of spirit of wine, after the same manner as that of jalap; and this method the Edinburgh college have directed. But all the spirits which can be expected to be employed for this purpose among us, are accompanied with some degree of bad flavour: this adheres most strongly to the phlegmatic part of the spirit, which evaporating last, must communicate this ill flavour to the extract; a circumstance of very great consequence, as this medicine is designed for those whose stomachs are too weak to bear a due quantity of bark in substance. Ten or twelve-grains of the hard extract are reckoned equivalent to about half a dram of the bark itself.

In the Peruvian bark, however, we may readily distinguish two different kinds of tastes, an astringent and a bitter one; the former seems to reside principally in the resinous matter, and the latter chiefly in the gummy. The watery extract is moderately strong in point of bitterness, but of the astringency it has only a small degree. The pure resin, on the other hand, is strong in astringency, and weak in bitterness. Both qualities are are united in the extract with the resin; which appears to be the best preparation of this kind that can be obtained from this valuable drug.

Extract of cascarilla. L.

This extract, which is now for the first time introduced into the pharmacopoeia of the London college, and which has not yet obtained a place in that of Edinburgh, is directed to be prepared by spirit and water in the same manner as the extract of bark with the resin. It possesses, in a concentrated state, the active constituent parts of the cascarilla, and has accordingly been already received into several of the best foreign pharmacopoeias. In some of these, as the Pharmacopoeia Suecica, it is a mere watery extract; but in others, as the Pharmacopoeia Rossica, the aid both of spirits and water are conjoined; and this we consider as the best preparation.

Extract of jalap. E.

Take of jalap root one pound; rectified spirit of wine, four pounds. Digest four days, and pour out the tincture. Boil the remaining magma in ten pounds of water to two pounds; then strain the decoction, and evaporate it to the consistence of pretty thin honey. Draw off the spirit from the tincture by distillation till what remains becomes thick. Then mix the liquors thus inspissated; and keeping them constantly stirring, evaporate to a proper consistence.

The extract of jalap is directed to be prepared by the London college in the same manner as their extract of Peruvian bark with the resin, which differs in nothing from the mode of preparation above directed.

This extract is an useful purgative; by some thought preferable to the crude root, as being of more uniform strength, and as the dose, by the rejection of the woody parts, is rendered smaller: the mean dose is 12 grains. If the spirituous tincture were inspissated by itself, it would afford a resinous mass, which, unless thoroughly divided by proper admixtures, occasions violent griping, and yet does not prove sufficiently cathartic; the watery decoctions yield an extract which operates very weakly: both joined together, as in this preparation, compose an effectual and safe purge. This method of making extracts might be advantageously applied to several other resinous substances, as the dry woods, roots, barks, &c. A small quantity of spirit takes up the resin; and much less water than would otherwise be necessary, extracts all the other soluble parts.

In a former edition of the Edinburgh Pharmacopoeia, a little fixed alkaline salt was ordered to be added to the water in which the jalap is boiled after the action of spirit; on a supposition that this would enable the water to extract more from the root than it could by itself. But, so far as the quantity of the alkaline salt could go, it had the opposite effect, impeding the action of the water. The resinous parts of the jalap are dissolved by the spirit; and little other than the gummy matter remains for water to extract. Now, if pure gum arabic be put into water along with any alkaline salt, the salt will render the water incapable of dissolving the gum; if the gum be dissolved first, the addition of any alkaline salt will precipitate it.

Extract of senna. L.

Take of senna, one pound; distilled water, one gallon. Boil the senna in the distilled water, adding after its decoction a little rectified spirit of wine. Evaporate the strained liquor to a proper thickness.

This extract had no place in our former pharmacopoeia, but may be considered as an useful addition.

The resinous parts of senna are in so small a proportion to the gummy, that they are readily boiled out together. The spirit may be added when the decoction is reduced to one half or to three pints.

This extract is given as a gentle purgative from 10 grains to a scruple; or, in less quantity, as an assistant to the milder laxatives.

Purified opium. L.

Take of opium, cut into small pieces, one pound; proof-spirit of wine, 12 pints. Digest the opium with a gentle heat, stirring now and then till it be dissolved, and filter through paper. Dilute the tincture, so prepared, to a proper thickness.

Purified opium must be kept in two forms; one soft, proper for forming into pills; the other hard, which may be reduced into powder.

Opium was formerly purified by means of water; and in this state it had the name in our pharmacopoeia of extractum thebaicum. But proof-spirit has been found, by experiments, to be the best menstruum for opium, having dissolved three-fourths of dried opium, which was much more than was taken up either by rectified spirit or water. Hence we thus obtained most entirely the constituents of opium free from any adhering impurities: but it has been imagined that some particular advantages arise from the parts which are extracted by water, especially after long digestion; and accordingly the following extract of opium has been recommended by Mr Beaumé.

Extract of opium prepared by long digestion.

Let five pounds of good opium, cut in pieces, be boiled about half an hour, in 12 or 15 quarts of water: strain the decoction, and boil the remainder once or twice in fresh water, that so much of the opium as is insoluble in water may be got out. Evaporate the strained decoctions to about six quarts; which being put into a tin cucurbit, placed in a sand-bath, keep up such a fire as may make the liquor nearly boil, for three months together if the fire is continued day and night, and for six months if it is intermitted in the night; filling up the vessel with water in proportion to the evaporation, and scraping the bottom with a wooden spatula from time to time, to get off the sediment which begins to precipitate after some days digestion. The sediment needs not to be taken out till the boiling is finished; at which time the liquor is to be strained when cold, and evaporated to an extract of a due consistence for being formed into pills.

The author observes, that by keeping the liquor strongly boiling, the tedious process may be considerably expedited, and the six months digestion reduced to to four months; that in the beginning of the digestion, a thick, viscous, oily matter rises to the top, and forms a tenacious skin as the liquor cools; this is supposed to be analogous to essential oils, though wanting their volatility: that the oil begins to disappear about the end of the first month, but still continues sensible till the end of the third, forming oily clouds as often as the liquid cools: that the resin at the same time fettles to the bottom in cooling, preserving for a long while its resinous form, but by degrees becoming powdery, and incapable of being any longer softened, or made to cohere by the heat: that when the process is finished, part of it still continues a perfect resin, dissoluble in spirit of wine, and part an indissoluble powder: that when the digested liquor is evaporated to about a quart, and set in the cold till next day, it yields a brownish earthy saline matter, called the effluvial salt of opium, in figure nearly like the sedative salt obtained from borax, intermingled with small needle-like crystals. He gives an account of his having made this preparation six or seven times. The vessel he made use of was about two inches and a half diameter in the mouth: the quantity of water evaporated was about 24 ounces a day, and from 130 to 140 quarts during the whole digestion. Out of 64 ounces of opium, 17 ounces remained undissolved in the water; the quantity of resinous matter precipitated during the digestion, was 12 ounces: from the liquor, evaporated to a quart, he obtained a dram of effluvial salt, and might, he says, have separated more; the liquor being then further evaporated to a pilular consistence, the weight of the extract was 31 ounces.

It is supposed that the narcotic virtue of opium resides in the oily and resinous parts; and that the gummy extract, prepared by the above process, is endowed with the calming, sedative, or anodyne powers of the opium, divested of the narcotic quality as it is of the smell, and no longer productive of the disorders which opium itself, and the other preparations of it, frequently occasion. A case is mentioned, from which the innocence and mildness of the medicine are apparent; 50 grains having been taken in a day, and found to agree well, where the common opiate preparations could not be borne. But what share it possesses of the proper virtues of opium is not so clear; for the cure of convulsive motions of the stomach and vomiting, which at length happened after the extract had been continued daily in the above doses for several years (plusieurs années), cannot perhaps be ascribed fairly to the medicine.

If the theory of the process, and of the alteration produced by it in the opium, be just, a preparation equivalent to the above may be obtained in a much shorter time. If the intention is to separate the resinous and oily parts of opium, they may be separated by means of pure spirit of wine, in as many hours as the digestion requires months. The separation will also be as complete, in regard to the remaining gum, tho' some part of the gum will in this method be lost, a little of it being taken up by the spirit along with the other principles.

In what particular part of opium its peculiar virtues reside, has not perhaps been incontrovertibly ascertained; but this much seems clear from experiment, that the pure gum, freed from all that spirit can dissolve, does not differ essentially in its soporific power from the resinous part.

There are grounds also to presume, that by whatever means we destroy or diminish what is called the narcotic, soporific, virulent quality of opium, we shall destroy or diminish likewise its salutary operation. For the ill effects which it produces in certain cases, seem to be no other than the necessary consequences of the same power, by which it proves so beneficial in others.

Extract of wormwood. Suec.

Take any quantity of the tops of wormwood, and pour upon it double its weight of water. Boil it for a short time over a gentle fire, then press out the liquor. Boil the residuum again in a fresh quantity of water, and after expression, strain it. Let the strained liquor be evaporated in a water-bath to a proper consistence.

In this extract we have one of the strongest vegetable bitters in its most concentrated state: and though it is not perhaps to be considered as superior to the extract of gentian, yet it furnishes a good variety, and is a more agreeable form for exhibiting the wormwood than that of strong tincture.

Extract of dandelion. Suec.

This is directed to be prepared from the roots of the dandelion, collected early in the spring, or late in the autumn, in the same manner as the extractum abinitio. And as far as the dandelion really possesses a refulgent, aperient, or diuretic power, it furnishes a convenient form for obtaining these effects from it. But as the dandelion is well known to abound with a milky juice, it is probable that the activity of the medicine would be increased from employing spirit also in the extraction of its medical virtues.

Watery extract of aloes. Suec.

Take of hepatic aloes one pound; cold spring-water, four pounds; juice of citrus, one pound. Macerate them in a glass vessel for one or two days, shaking the vessel from time to time. When the resinous and feculent parts have subsided, pour off the liquor; and to the residuum add fresh water, till by this treatment it obtains a little impregnation. Let the strained liquors be then evaporated in a warm bath to the consistence of honey.

Although aloes are perhaps upon the whole a better medicine, in their crude state, where the gummy and resinous matters are united, than in those preparations where either is retained separately, yet the gummy extract which is thus obtained is at least less disagreeable, having little smell or taste, while at the same time it is a very powerful purgative; hence it may be usefully employed at least on some occasions.

Gummy extract of myrrh. Brun.

Take of myrrh, half a pound; spring-water, four pounds. Let the myrrh be dissolved by gentle dilution and repeated agitation of the vessel for four or five days: let the water swimming above the myrrh be then poured off, strained, and evaporated to the consistence of an extract. This watery extract of myrrh may be useful in some cases, as being much deprived of the heating qualities which it has in its crude state; and if it furnishes us in phthisis pulmonalis with that useful remedy which some imagine, it may probably be most advantageously exhibited under this form.

Refined liquorice. Dan.

Take any quantity of Spanish liquorice, cut it into small fragments, dissolve it in tepid water, and strain the solution. Let the liquor be poured off from the feculent part after it has subsided, and infusated by a gentle heat.

The extract of liquorice already mentioned, when it is prepared with due skill and attention, is unquestionably an article superior to this; but it is very rarely met with in the shops of our druggists or apothecaries as prepared by themselves. In its place they very commonly employ either the extract brought from Spain, or that prepared by the makers of liquorice at home; both of which very commonly abound with impurities. It has even been said, that a portion of sand is not unfrequently mixed with it to increase the weight; but whether the impurities arose from this cause, or from the slovenly mode of preparing it, considerable advantage must arise from freeing it from all these before it be employed for any purpose in medicine. And in modern practice it is frequently used, not only in troches and pills, but also for suspending powders in waters; such as the powder of Peruvian bark: and the powder of bark, when thus suspended, is in general taken more readily by children than in any other form. Hence considerable advantage must arise from a proper and easy mode of purifying it, which the above process affords. We are of opinion, therefore, that although a place be with propriety given to the extract of liquorice prepared by the apothecaries themselves, refined liquorice ought also to be introduced into our pharmacopoeias; and it would be very convenient to keep it in the shops in a soft consistence fit for making pills, as it would not only answer that purpose, but admit of a ready solution in water when requisite. To this consistence, indeed, an objection occurs, from its being apt to grow mouldy; but this may be effectually prevented by the addition of a small proportion of spirit.

Besides the extracts which we have here selected from the foreign pharmacopoeias, many others also still retain a place in several of these; such, for example, as the extractum arnicae, artemisiae, bryoniae, cardui, centaureae, cachelariae, croci, &c. Several of these had formerly a place in our pharmacopoeias, but are now with propriety rejected; because, where these substances are to be employed, they may with much more advantage be exhibited under other forms. And, indeed, although under the form of extract we have a condensation of some active principles, yet by the action of fire others are very apt to be lost. Hence, where any article can be conveniently exhibited in substance, that form is in general preferable; and recourse should be had to extracts only with a view to some particular intention. Our colleges therefore have with propriety diminished the number of them; and even those which they have adopted are but seldom to be had recourse to in preference to other forms. In the formation of many of those extracts, retained by the foreign colleges, the preparations and most valuable principles are either entirely dissipated or destroyed by the fire. We think, however, that advantages may sometimes be obtained from adopting these which are here selected.

The chapter on extracts and resins in the London pharmacopoeia is concluded with the following general directions:

1. All the extracts, during the time of infusion, must be gently agitated. 2. On all the softer watery extracts, a small quantity of spirit of wine must be sprinkled.

Chap. V. Expresed Oils.

Expressed oils are obtained chiefly from certain seeds and kernels of fruits, by thoroughly pounding them in a stone mortar, or, where the quantities are large, grinding them in mills, and then including them in a canvas bag, which is wrapped in a hair-cloth, and strongly pressed between iron plates. The canvas, if employed alone, would be squeezed so close to the plates of the press as to prevent the oil from running down; by the interposition of the hair-cloth a free passage is allowed.

Sundry machines have been contrived, both for grinding the subject and pressing out the oil, in the way of business. To facilitate the expression, it is usual to warm either the plates of the press, or the subject itself after the grinding, by keeping it stirring in a proper vessel over the fire; the oil, liquefied by the heat, separates more freely and more plentifully. When the oil is designed for medicinal purposes, this practice is not to be allowed; for heat, especially if its degree be sufficient to be of any considerable advantage for promoting the separation, renders the oil less soft and palatable, imparts a disagreeable flavour, and increases its disposition to grow rancid; hence the colleges both of London and Edinburgh expressly require the operation to be performed without heat.

Nor are the oils to be kept in a warm place after their expression. Exposed for a few days to a heat no greater than that of the human body, they lose their emollient quality, and become highly rancid and acrimonious. Too much care cannot be taken for preventing any tendency to this acid irritating state in medicines, so often used for abating immoderate irritation.

So much are these oils disposed to this injurious alteration, that they frequently contract an acrimony and rancidity while contained in the original subjects. Hence great care is requisite in the choice of the unctuous seeds and kernels, which are often met with very rancid; almonds are particularly liable to inconveniences of this kind.

Expressed oils are prepared for mechanic uses from sundry different subjects, as nuts, poppy-seed, hemp-seed, rape-seed, and others. Those directed for medicinal purposes in the London and Edinburgh pharmacopoeias are the following:

Oil of almonds. L. E.

Pound fresh almonds, either sweet or bitter, in a mortar, then press out the oil in a cold press. In the same manner is to be expressed oil of linseed and oil of mustard-seed.

The oil of almonds is prepared from the sweet and bitter almonds indifferently, the oils obtained from both sorts being exactly the same. Nor are the differences of the other oils very considerable, the discriminating qualities of the subjects not residing in the oils that are thus obtained by expression. The oil of linseed requires indeed some peculiarities from containing a proportion of vegetable mucilage; but the oil of mustard-seed is as soft, infipid, and void of pungency, as that of sweet almonds, the pungency of the mustard remaining entire in the cake left after the expression. The several oils differ in some of their properties from each other; but in medicinal qualities they appear to be all nearly alike, and agree in one common emollient virtue. They soften and relax the solids, and obtund acrimonious humours; and thus become serviceable internally in pains, inflammations, heat of urine, hoarse-voiced, tickling coughs, &c. in glisters, for lubricating the intestines, and promoting the ejection of indurated feces; and in external applications, for tension and rigidity of particular parts. Their common dose is half an ounce; in some cases they are given to the quantity of three or four ounces. The most commodious forms for their exhibition we shall see hereafter in the chapter of Emulsions.

**Castor oil. L.**

This oil is directed by the London college to be prepared in the same manner as that of almonds, the seeds or nuts being taken from the husks before putting them into the mortar. *Palma Christi*, or castor oil, (See Oleum Palme Christi, and Ricinus), is a gentle and useful purgative; it generally produces its effects without griping, and may be given with safety where acid purgatives are improper. With adults, from half an ounce to an ounce is generally requisite for a dose. This article, however, is very seldom prepared by our apothecaries, being in general imported under the form of oil from the West Indies; hence the Edinburgh college have not mentioned it among their preparations, but merely given it a place in their list of the materia medica. But when our apothecaries prepare it for themselves, they are more certain of obtaining a pure oil, and one too obtained without the aid of heat, which is often employed, and gives a much inferior oil. It is therefore with propriety that the London college have given directions for the preparation of it by the apothecary himself. But even the London college have not thought it necessary to give directions for the preparation of the following expressed oils, which, as well as the oleum ricini, are also introduced into the list of the materia medica by the Edinburgh college.

**Expressed oil of bay berries, mace, olives, palm.**

These also are principally considered as possessing only an emollient virtue; but as far as they have been supposed to exert any peculiar qualities, these we have had occasion to mention in other parts of the work, when treating of the articles from which they are obtained. See Olea, Mace, &c.

**Oil of chocolate nuts. Suec.**

Express the oil from the nuts slightly toasted, and freed from their coverings.

In this oil we have the nutritious part of chocolate, free from those aromatics with which it is united in the state in which it is kept in our shops. And although under the form of chocolate it fits perhaps more easily on the stomach than in most other forms; yet where, from any particular circumstance, aromatics are contraindicated, the oil in its pure state gives us an opportunity of employing in different ways this mild nutritious article.

**Oil of hyoscyamus. Suec.**

This oil is directed to be obtained by expression from the seeds of the hyoscyamus, in the same manner as that of almonds.

Of the narcotic powers of the hyoscyamus some observations have already been offered. This oil, although an expressed one, is said to retain these virtues; and accordingly it has entered the composition of some anodyne ointments and plasters. We are, however, inclined to think, that when the sedative power of hyoscyamus is wanted under the form of oil, it may be best obtained from impregnating olive oil by the leaves of the plant.

**Egg oil. Suec.**

Take any quantity of fresh eggs, boil them till they be quite hard; then take out the yolks, break them in pieces, and roast them gently in a frying-pan till they feel greasy when pressed between the fingers; put them while warm into a hair-bag, and express the oil.

The yolk of the egg is well known to be a mild nutritious substance; but notwithstanding the many virtues at one time attributed to it, of being paregoric and soporific, as externally applied; and of being useful in stomach complaints, dysentery, and different affections of the alimentary canal, when taken internally;—it is much to be doubted whether it be in any other way useful in medicine than as an article of diet; and we are very uncertain whether any particular purpose in medicine will be answered by this expressed oil: but as it holds a place in most of the foreign pharmacopoeias of modern date, it may justly be considered as deserving some attention.

Notwithstanding the justice of the observation respecting the great similarity of expressed oils in general, yet there can be no doubt that in some instances they obtain a peculiar impregnation. This manifestly appears in the oleum ricini, oleum nucis moschatae, and some of the others mentioned above. Indeed oils expressed from aromatic substances in general retain some admixture of the essential oil of the subject from which they are expressed. Nor is this surprising, when we consider that in some cases the essential oil exists in a separate state even in the growing plant.

The rinds of the several varieties of oranges, lemons, and citrons, yield by a kind of expression their essential oils oils almost pure, and nearly similar to those which are obtained from them by distillation. The essential oils, in which the fragrance and aromatic warmth of these fruits reside, are contained in numerous little vehicles, which may be distinguished by the naked eye, spread all over the surface of the peel. If the rind be cut in slices, and the slices separately doubled or bent in different parts, and squeezed between the fingers, the vehicles burst at the bending, and discharge the oil in a number of fine slender jets. A glass plate being set upright in a glass or porcelain vessel, and the slices squeezed against the plates, the little jets unite into drops upon the plate, and trickle down into the vessel beneath. But though this process affords the true native oil in the same state wherein it existed in the subject, unaltered by fire or other agents, it is not practicable to advantage unless where the fruit is very plentiful, as only a small part of the oil it contains can thus be extracted or collected.

The oil is more perfectly separated by rubbing the rind upon a lump of sugar. The sugar, by the inequality of its surface, produces the effect of a rasp in tearing open the oily vehicles, and in proportion as the vehicles are opened the sugar imbibes the oil. When the outward part of the lump is sufficiently moistened, it is scraped off, and the operation continued on the fresh surface. The oil thus combined with the sugar is fit for most of the uses to which it is applied in a fluid state. Indeed the pure essential oils obtained by distillation are often purposely mixed with sugar to render their use the more commodious.

**CHAP. VI. Essential Oils.**

Essential oils are obtained only from odoriferous substances; but not equally from all of this class, nor in quantity proportional to their degree of odour. Some which, if we were to reason from analogy, should seem very well fitted for this process, yield extremely little oil, and others none at all. Roses and camomile flowers, whose strong and lasting smell promises abundance, are found upon experiment to contain but a small quantity; the violet and jasmine flower, which perfume the air with their odour, lose their smell upon the gentlest motion, and do not afford the least perceptible mark of oil on being distilled unless immense quantities are submitted to the operation at once; while fennel, whose disagreeable scent extends to no great distance, gives out the largest proportion of oil of almost any vegetable known.

Nor are the same plants equally fit for this operation when produced in different soils or seasons, or at different times of their growth. Some yield more oil if gathered when the flowers begin to fall off than at any other time. Of this we have examples in lavender and rue; others, as sage, afford the largest quantity when young, before they have sent forth any flowers; and others, as thyme, when the flowers have just appeared. All fragrant herbs yield a larger proportion of oil when produced in dry soils and warm summers than in opposite circumstances. On the other hand, some of the disagreeable strongly-scented ones, as wormwood, are said to contain most in rainy seasons and when growing in moist rich grounds.

Several of the chemists have been of opinion, that herbs and flowers, moderately dried, yield a greater quantity of essential oil than if they were distilled when fresh. It is supposed, that the oil being already blended, in fresh plants, with a watery fluid, great part of it remains diffused through the water after the distillation, divided into particles too minute to unite and be collected; whereas in drying, the oily parts, on the exhalation of the moisture which kept them divided and dispersed, run together into globules, which have little disposition to mingle with watery fluids, and easily separate from the water employed in the distillation.

This theory, however, does not appear to be quite satisfactory; for though the oil be collected in the subject into distinct globules, it does not rise in that form, but is resolved into vapour, and blended and coagulated by the heat with the vapour of the water; and if the oil in a dry plant was less disposed to unite with aqueous fluids than in a fresh one, the dry ought to yield a weaker infusion than the fresh; the contrary of which is generally found to obtain. As the oil of the dry plant is most perfectly extracted and kept dissolved by the water before the distillation, it is difficult to conceive any reason why it should have a greater tendency to separate from the water afterwards.

The opinion of dry plants yielding most oil seems to have arisen from an observation of Hoffman, which has probably been misinterpreted: "A pound (he says) of dry spike flowers yields an ounce of oil, but if they were distilled fresh they would scarcely yield above half an ounce; and the case is the same in balm, sage, &c. The reason is, that in drying the watery humidity exhales; and as from two pounds of a fresh plant we do not obtain above one pound of dry, and little of the subtle oil evaporates in the drying, it follows, that more oil ought to be afforded by the dry than by the fresh." The meaning of which seems to be no more than this, that if two pounds of a fresh plant are by drying reduced to one without any loss of the oil, then the one pound dry ought to be equivalent to the two fresh. A late writer quotes an experiment of Neumann, which appears to be misunderstood in the same manner; for Neumann, in the place referred to, says only that dry wormwood is found to yield much more oil than an equal weight of the fresh plant. Trials are yet wanting in which fresh and dry plants have been brought to a fair comparison, by dividing a quantity of the subject into two equal weights, and distilling one while fresh, and the other after it has been carefully and moderately dried.

But whatever may be the effect of moderate excitation, it is certain, that if the drying be long continued, the produce of oil will be diminished, its colour altered, and its smell impaired.

With regard to the proportion of water to be employed, if whole plants moderately dried are used, or the shavings of woods, as much of either may be put into the vessel as, lightly pressed, will occupy half its cavity; and as much water may be added as will fill two-thirds of it. The water and ingredients altogether should never take up more than three-fourths of the still; there should be liquor enough to prevent any danger of an empyreuma, but not so much as to be too apt to boil over into the receiver. The maceration should be continued so long that the water may fully penetrate the parts of the subject. To promote this effect, woods should be thinly shaved across the grain or fawn, roots cut transversely into thin slices, barks reduced into coarse powder, and seeds slightly bruised. Very compact and tenacious substances require the maceration to be continued a week or two, or longer; for those of a softer and looser texture, two or three days are sufficient; while some tender herbs and flowers not only stand in no need of maceration, but are even injured by it.

Whether the addition of sea-salt, which some have recommended, be of any real service, is much to be doubted. The uses generally assigned to it are, to penetrate and unlock the texture of the subject more effectually than simple water could do, and to prevent the fermentation or putrefaction which the matter is apt to run into during the length of time for which the maceration is often continued. But sea-salt seems rather to harden and condense, than to soften and resolve, both vegetable and animal subjects; and if it prevents putrefaction, it must, on that very account, be injurious rather than of service. The resolution here aimed at approaches near to a beginning putrefaction; and saline substances, by retarding this, prolong the maceration far beyond the time that would otherwise be necessary. It is in the power of the operator, when he perceives the proofs coming near this pitch, to put a stop to it at pleasure, by proceeding immediately to distillation. By this means the whole affair will be finished in a very little time, with at least equal advantage in every other respect; provided the manual operations of pounding, rasping, and the like, which are equally necessary in either case, be minutely complied with.

Bodies of a very viscous and compact texture were directed, in the Edinburgh pharmacopoeia, to be fermented for some days with a little yeast. Half their quantity of water is sufficient for performing the fermentation; as much more as is necessary is to be added afterwards before the distillation. This process undoubtedly promotes the resolution of the subject, and the extrication of the oil. It rarely happens, however, that assistances of this kind are needful. Particular care must be had not to continue the fermentation too long; or to give a bad flavour to the oil by an ill-chosen ferment, or using too large a quantity of any.

Some chemists pretend, that by the addition of salts and acid spirits they have been enabled to gain more oil from certain vegetable matters than could possibly be got from them without such assistance. Experiments made on purpose to settle this point seem to prove the contrary: this at least is constantly found to be true, that where there is any reason to think the produce greater than usual, the quality of the oil is proportionally injured. The quantity of true essential oil in vegetables can by no means be increased; and what is really contained in them may be easily separated without any addition of this kind. All that saline matters can do in this respect is to make the water susceptible of a greater degree of heat than it can sustain by itself; and thus enable it to carry up a gross unctuous matter not volatile enough to rise with pure water: this gross matter, mingling with the pure oil, increases the quantity, but at the same time must necessarily debauch its quality. And indeed, when water alone is used, the oil which comes over about the end of the operation is remarkably less fragrant, and of a thicker consistence, than that which rises at the beginning: distilled a second time, with a gentle heat, it leaves a large quantity of gross almost insipid refrinous matter behind.

The choice of proper instruments is of great consequence for the performance of this process to advantage. There are some oils which pass freely over the swan-neck of the head of the common still; others, less volatile, cannot easily be made to rise so high. For obtaining these last, we would recommend a large low head, having a rim or hollow canal round it. In this canal the oil is detained on its first ascent, and thence conveyed at once into the receiver, the advantages of which are sufficiently obvious.

With regard to the fire, the operator ought to be expeditious in raising it at first, and to keep it up, during the whole process, of such a degree that the oil may freely distil; otherwise the oil will be exposed to an unnecessary heat; a circumstance which ought as much as possible to be avoided. Fire communicates to all these oils a disagreeable impregnation, as is evident from their being much less grateful when newly distilled, than after they have stood for some time in a cool place; the longer the heat is continued, the more alteration it must produce in them.

The greater number of oils require for their distillation the heat of water strongly boiling: but there are many also which rise with a heat considerably less; such as those of lemon and citron-peel, of the flowers of lavender and rosemary, and of almost all the more odoriferous kinds of flowers. We have already observed, that these flowers have their fragrance much injured, or even destroyed, by beating or bruising them; it is impaired also by the immersion in water in the present process, and the more so in proportion to the continuance of the immersion and the heat: hence oils, distilled in the common manner, prove much less agreeable in smell than the subjects themselves. For the distillation of substances of this class another method has been contrived; instead of being immersed in water, they are exposed only to its vapour. A proper quantity of water being put into the bottom of the still, the odoriferous herbs or flowers are laid lightly in a basket, of such a size that it may enter into the still, and rest against its sides, just above the water. The head being then fitted on, and the water made to boil, the steam, percolating through the subject, imbibes the oil, without impairing its fragrance, and carries it over to the receiver. Oils thus obtained possess the odour of the subject in an exquisite degree, and have nothing of the disagreeable scent perceptible in those distilled by boiling them in water in the common manner.

It may be proper to observe, that those oils which rise with a less heat than that of boiling water, are generally called, by the chemical and pharmaceutical writers, light oils; and those which require the heat of water strongly boiling, are called ponderous. We have avoided these expressions, as they might be thought to relate to the comparative gravities of the oils; with which the volatility or fixedness have no connection. Olive oil is lighter than most of the ef- fential oils; but the heat requisite to make it distil, exceeds that in which the heaviest essential oil distils, considerably more than the heat of boiling water exceeds that of ice.

The water employed in the distillation of essential oils always imbibes some portion of the oil; as is evident from the smell, taste, and colour, which it acquires. It cannot, however, retain above a certain quantity; and therefore, such as has been already used and consequently saturated with oil, may be advantageously employed, instead of common water, in a second, third, or any future distillation of the same subject.

Some late chemical writers recommend, not the water which comes over, but that which remains in the still, to be used a second time. This can be of no service; as containing only such parts of the vegetable as are incapable of arising in distillation, and which serve only to impede the action of the water as a menstruum, and to endanger an empyreuma.

After the distillation of one oil, particular care should be taken to cleanse the worm before it be employed in the distillation of a different plant. Some oils, those of wormwood and aniseeds for instance, adhere to it so tenaciously, as not to be melted out by heat, or washed off by water: the best way of cleansing the worm from these, is to run a little spirit of wine through it.

Essential oils, after they are distilled, should be suffered to stand for some days, in vessels loosely covered with paper, till they have lost their disagreeable fiery odour, and become limpid: then put them up in small bottles, which are to be kept quite full, closely stoppered, in a cool place: with these cautions, they will retain their virtues in perfection for many years.

When carelessly kept, they in time gradually lose their flavour, and become gross and thick. Some endeavour to recover them after they have undergone this change, by grinding them with about thrice their weight of common salt, then adding a large proportion of water, and distilling them afresh: the purer part rises thin and limpid, preserving a great degree of the pristine smell and taste of the oil, though inferior in both respects to the original oil. This rectification, as it is called, succeeds equally without the salt: the oils, when thus altered, are nearly in the same state with the turpentine, and other thickened oily juices, which readily yield their purer oil in distillation with water alone.

When essential oils have entirely lost their smell, some recommend adding them in the distillation of a fresh quantity of the oil of the same plant; by which means they are said to satiate themselves anew with the odorous matter, and become entirely renovated. This practice, however, ought doubtless to be disapproved, as being no other than a specious sophification; for it can do no more than divide, between the old and the new, the active matter which belongs to the new alone.

Essential oils, medicinally considered, agree in the general qualities of pungency and heat; in particular virtues, they differ as much as the subject from which they are obtained, the oil being the direct principle in which the virtues, or at least a considerable part of preparations and compositions, the virtues, of the several subjects reside. Thus the composition, carminative virtue of the warm seeds, the diuretic of juniper-berries, the emmenagogue of savin, the nervine of rosemary, the stomachic of mint, the antisepticus of savory-grass, the cordial of aromatics, &c. are supposed to be concentrated in their oil.

There is another remarkable difference in essential oils, the foundation of which is less obvious, viz. the degree of their pungency and heat. These are by no means in proportion, as might be expected, to those of the subject they were drawn from. The oil of cinnamon, for instance, is very pungent and fiery; in its undiluted state it is almost caustic; whereas cloves, a spice which in substance is far more pungent than the other, yields an oil which is far less so. This difference seems to depend partly on the quantity of oil afforded, cinnamon yielding much less than cloves, and consequently having its active matter concentrated into a smaller volume; partly on a difference in the nature of the active parts themselves; for though essential oils contain always the specific odour and flavour of their subjects, whether grateful or ungrateful, they do not always contain the whole pungency; this resides frequently in a more fixed resinous matter, and does not rise with the oil. After the distillation of cloves, pepper, and some other spices, a part of their pungency is found to remain behind: a simple tincture of them in rectified spirit of wine is even more pungent than their pure essential oils.

The more grateful oils are frequently used for reconciling to the stomach medicines of themselves distasteful. It has been customary to employ them as correctors for the resinous purgatives; an use which they do not seem to be well adapted to. All the service they can here be of, is, to make the resin fit more easily at first on the stomach: far from abating the irritating quality on which the virulence of its operation depends, these pungent oils superadd a fresh stimulus.

Essential oils are never given alone, on account of their extreme heat and pungency; which in some is so great, that a single drop let fall upon the tongue produces a gangrenous effect. They are readily imbibed by pure dry sugar, and in this form may be conveniently exhibited. Ground with eight or ten times their weight of sugar, they become soluble in aqueous liquors, and thus may be diluted to any assigned degree. Mucilages also render them miscible with water into an uniform milky liquor. They dilute likewise in spirit of wine; the more fragrant in an equal weight, and almost all of them in less than four times their own quantity; these solutions may be either taken on sugar, or mixed with syrups, or the like: on mixing them with water, the liquor grows milky, and the oil separates.

The more pungent oils are employed externally against paralytic complaints, numbness, pains, and aches, cold tumors, and in other cases where particular parts require to be heated or stimulated. The tooth-ache is sometimes relieved by a drop of these almost caustic oils, received on cotton, and cautiously introduced into the hollow tooth. Let these oils be drawn off by distillation, from an alembic with a large refrigeratory; but, to prevent an empyreuma, water must be added to the ingredient; in which they must be macerated before distillation.

The water which comes over with the oil in distillation is to be kept for use.

**Essential oils. E.**

- Of the herbs of garden mint, - Of peppermint, - Of savin, - Of the tops of rosemary, - Of the flowering spikes of lavender, - Of aniseeds, - Of juniper-berry, - Of jaffra root, - Of Jamaica pepper.

These are prepared almost in the same manner as the simple distilled waters, excepting that for procuring the oil a somewhat less quantity of water is to be used. Seeds and woody matters are first to be bruised or rasped. The oil rises with the water; and as it is lighter or heavier, swims on the surface, or sinks to the bottom, from which it is afterwards to be separated.

It is, however, to be remarked, that, in preparing these distilled waters and oils, so many varieties must necessarily take place from the goodness of the subject itself, its texture, the time of the year, and such like circumstances, that a certain and general rule, which should strictly apply to each example, can scarcely be laid down; wherefore we have only explained the general method, leaving many things to be varied by the judgment of the operator.

To the directions for preparing these essential oils given by the London and Edinburgh colleges, we shall here next subjoin a few remarks on their medical properties.

**Essential oil of aniseeds. L. E.**

This oil possesses the taste and smell of the aniseeds in perfection. It is one of the mildest of the distilled oils; 15 or 20 drops may be taken at a time without danger, though common practice rarely goes so far as half this number. Its smell is extremely durable and diffusive; milk drawn from the breast after taking it, is found impregnated with its odour; and possibly this may be, in part, the foundation of the pectoral virtues usually ascribed to it; in flatulencies and colics, it is said by some to be less effectual than the seeds themselves.

It is remarkable of this oil, that it congeals, even when the air is not sensibly cold, into a butyrous consistency; and hence, in the distillation of it, the operator ought not to be over-fanciful in keeping the water in the refrigeratory too cool: it behoves him rather to let it grow somewhat hot, particularly towards the end of the process; otherwise the oil congealing may stop up the worm, as to endanger blowing off the head of the still, or at least a considerable quantity of oil will remain in it.

**Essential oil of caraway seeds. L.**

The flavour of this exactly resembles that of the caraway itself. It is a very hot and pungent oil; a single drop is a moderate dose, and five or six is a very large one. It is not unfrequently used as a carminative; and supposed by some to be peculiarly serviceable for promoting urine, to which it communicates some degree of its smell.

**Essential oil of lavender flowers. L. E.**

This oil, when in perfection, is very limpid, of a pleasant yellowish colour, extremely fragrant, possessing in an eminent degree the peculiar smell generally admired in the flowers. It is a medicine of great use, both externally and internally, in paralytic and lethargic complaints, rheumatic pains, and debilities of the nervous system. The dose is from one drop to five or six.

Lavender flowers yield the most fragrant oil, and considerably the largest quantity of it, when they are ready to fall off spontaneously, and the leaves begin to show themselves: the seeds give out extremely little. The flowers may be separated from the rest of the plant, by drying it a little, and then gently beating it: they should be immediately committed to distillation, and the process conducted with a well regulated gentle heat; too great heat would not only change the colour of the oil, but likewise make a disagreeable alteration in its smell.

**Essential oil of the leaves of peppermint. L. E.**

This possesses the smell, taste, and virtues of the peppermint in perfection; the colour is a pale greenish yellow. It is a medicine of great pungency and subtlety; and diffuses, almost as soon as taken, a glowing warmth through the whole system. In colics, accompanied with great coldness, and in some hysterical complaints, it is of excellent service. A drop or two are in general a sufficient dose.

**Essential oil of the leaves of common mint. L. E.**

This oil smells and tastes strongly of the mint, but is in both respects somewhat less agreeable than the herb itself. It is a useful stomachic medicine; and not unfrequently exhibited in want of appetite, weakness of stomach, retching to vomit, and other like disorders, when not accompanied with heat or inflammation: two or three drops, or more, are given for a dose. It is likewise employed externally for the same purposes; and is an useful ingredient in the stomachic plaster of the shops.

**Essential oil of the leaves of origanum. L.**

This oil has a very pungent acrimonious taste, and a penetrating smell. It has been chiefly employed externally as an errhine and for easing pains of the teeth. Essential oil of the leaves of pennyroyal. L.

This oil, in smell and taste, resembles the original plant; the virtues of which it likewise possesses. It is given in hysterical cases, from one to four or five drops.

Essential oil of rosemary. L. E.

The oil of rosemary is drawn from the plant in flower. When in perfection, it is very light and thin, pale, and almost colourless; of great fragrance, though not quite so agreeable as the rosemary itself. It is recommended, in the dose of a few drops, in nervous and hysterical complaints. Boerhaave holds it in great esteem against epilepsies and suppressions of the uterine purgations occasioned by weakness and inactivity.

Essential oil of juniper-berries. L. E.

This oil is a very warm and pungent one; of a strong flavour, not unlike that of the berries. In the dose of a drop or two, it proves a serviceable carminative and stomachic; in one of six, eight, or more, a stimulating, detergent, diuretic, and emmenagogue; it seems to have somewhat of the nature of the turpentine, or their distilled oil; like which it communicates a violent smell to the urine.

The oil of these berries resides partly in vesicles spread through the substance of the fruit, and partly in little cells contained in the seeds: when the berry is dry, and the oil hardened into a resinous substance, it becomes visible, on breaking the seeds, in form of little transparent drops. In order therefore to obtain this oil to advantage, we ought, previous to the distillation, to bruise the berry thoroughly, so as to break the seeds, and entirely lay open the oily receptacles.

Essential oil of saffron. L. E.

This is the most ponderous of all the known essential oils, but rises in distillation with sufficient ease: it appears limpid as water, has a moderately pungent taste, a very fragrant smell, exactly resembling that of the saffron. It stands greatly commended as a sudorific, and for purifying the blood and juices: it is likewise supposed to be of service in humoral asthmas and coughs. The dose is from one drop to eight or ten; though Geoffroy goes as far as twenty.

The decoction remaining after the distillation of the oil, affords by infusion an useful extract, of a mild, bitterish, subastringent taste. Hoffman says, he has given it with great benefit, in doses of a scruple, as a corroborant in cachectic cases, in the decline of intermittent fevers, and for abating hypochondriacal spasms.

Essential oil of savin leaves. L. E.

Savin is one of the plants which, in former editions of the Edinburgh pharmacopoeia, were directed to be lightly fermented before the distillation: this, however, is not very necessary; for savin yields, without fermentation, and even without any such maceration, a very large quantity of oil. The oil of savin is a celebrated uterine and emmenagogue; in cold phlegmatic habits, it is undoubtedly a medicine of great service, though not capable of performing what it has been often represented to do. The dose is, two or three drops, or more.

Essential oil of Jamaica pepper. E.

This is a very elegant oil, and may be used as a succedaneum to those of some of the dearer spices. It is of a fine pale colour; in flavour more agreeable than the oil of cloves, and not far short of that of nutmegs. It sinks in water, like the oils of some of the eastern spices.

Oil of fossil tar. L.

Distil fossil tar, the bitumen petroleum, in a sand heat. The oil obtained from this tar will be more or less thin according to the continuance of the distillation; and by its continuance the tar will at last be reduced to a black coal; and then the oil will be pretty deep in colour, though perfectly fluid. This oil has a property similar to that of the tincture of nephritic wood in water, appearing blue when looked upon, but of an orange colour when held between the eye and the light. By long keeping it loses this property. It is less disagreeable than some of the other empyreumatic oils which had formerly a place in our pharmacopoeia, such as the oleum lateritium, though very acid and stimulating.

Oil of turpentine. L.

Take of common turpentine five pounds; water four pints. Distil the turpentine with the water from an alembic of copper. After the distillation of the oil, what remains is yellow resin.

Rectified oil of turpentine. L.

Take of oil of turpentine one pound; water four pints. Distil.

The process here proposed for rectifying this oil, is not only tedious but accompanied with danger. For unless the luting be very close, some of the vapour will be apt to get through; and if this catch fire, it will infallibly burst the vessels. This rectified oil, which in many pharmacopoeias is styled aetherial, does not considerably differ in specific gravity, smell, taste, or medical qualities, from the former.

The spirit of turpentine, as this essential oil has been styled, is not unfrequently taken internally as a diuretic and sudorific. And in these ways it has sometimes a considerable effect when taken even to the extent of a few drops only. It has, however, been given in much larger doses, especially when mixed with honey. Recourse has principally been had to such doses in cases of chronic rheumatism, particularly in those modifications of it which are styled sciatica and lumbago. But they have not been often successful, and sometimes they have had the effect of inducing bloody urine.

Animal oil. L.

Take of oil of hartshorn one pound. Distil three times.

Rectified oil of horns, or animal oil. E.

Take of empyreumatic oil, newly distilled from the horns of animals, as much as you will. Distil with a gentle heat, in a matras furnished with a head, as long as a thin colourless oil comes over, which is to be freed of alkaline salt and spirit by means of water. water. That this oil may remain limpid and good, it ought to be put up in small phials, completely filled and inverted, having previously put into each phial a few drops of water, that on inverting it the water may interpose itself between the oil and the mouth of the phial.

The quantity of oil employed in this process should be considerable; for it leaves so much black matter behind in the several distillations, that it is reduced at last to a small portion of its original quantity. It is said, that the product is rendered more limpid, by mixing the oil with quicklime into a soft paste; the lime keeping down more of the gross matter than would remain without such an addition. The quicklime may here also perhaps act by abstracting fixed air; to the absorption of which we are disposed to refer in some measure the spoiling of the oil on exposure to the atmosphere.

The oil was first introduced by Dippelius, whose name it has since generally borne.

Animal oils thus rectified, are thin and limpid, of a fulsome, penetrating, not disagreeable smell and taste. They are strongly recommended as anodynes and antispasmodics, in doses from 15 to 30 drops. Hoffman reports, that they procure a calm and sweet sleep, which continues often for 20 hours, without being followed by any languor or debility, but rather leaving the patient more alert and cheerful than before; that they procure likewise a gentle sweat, without increasing the heat of the blood: that given to 20 drops or more, on an empty stomach, six hours before the accession of an intermittent fever, they frequently remove the disorder; and that they are likewise a very generous remedy in inveterate and chronic epilepsies and in convulsive motions, especially if given before the usual time of the attack, and preceded by proper evacuations.

The empyreumatic oils of vegetables, rectified in the same manner by repeated distillations, suffer a like change with the animal; losing their dark colour and offensive smell, and becoming limpid, penetrating, and agreeable: in this state they are supposed, like the animal oil, to be anodyne, antispasmodic, and diaphoretic or sudorific. It is observable, that all the empyreumatic oils dissolve in spirit of wine, and that the sooner they are rectified or redistilled, they dissolve the more readily; a circumstance in which they differ remarkably from essential oils, which, by repeated distillations, become more and more difficult of solution.

How far these preparations really possess the virtues that have been ascribed to them, has not yet been sufficiently determined by experience; the tediousness and trouble of the rectification having prevented their coming into general use, or being often made. They are liable also to a more material inconvenience, in regard to their medicinal use, precariousness in their quality; for how perfectly forever they be rectified, they gradually lose in keeping the qualities they had received from that process, and return more and more towards their original febrile state.

Oil and salt of amber. E.

Take equal parts of amber reduced to a powder and of pure sand. Mix them, and put them into a glass retort; of which the mixture may fill one half: then adapt a large receiver, and distil in a sand furnace, with a fire gradually increased. At first a spirit will come over, with some yellow oil; then more yellow oil, along with a little salt; and on raising the heat, more of the salt, with a reddish and black coloured oil. When the distillation is finished, empty the liquor out of the receiver; and having collected together the salt which adheres to the sides, dry it by gentle pressure between the folds of blotting paper; then purify it by solution in warm water and by crystallization.

Rectified oil of amber.

Distil the oil in a glass retort with six times its quantity of water till two-thirds of the water have passed into the receiver; then separate the rectified oil from the water, and keep it for use in close shut vessels. E.

Take of oil of amber one pound. Distil three times. L.

The London college introduce their directions for the preparation of the sal and oleum succini at an after part of their work, under the head of salis. Here we may only observe, that they direct it to be prepared from the amber alone, without the intervention of sand. But this makes no essential difference in the article when prepared.

The Edinburgh college have rejected what was formerly called the spirit, as being nothing else than the watery parts, fraught with the inert impurities of the bitumen and a very small portion of the salt. In the distillation of amber, the fire must for some time be continued gentle, scarce exceeding the degree at which water boils, till the aqueous phlegm and thin oil have arisen; after which it is to be slowly increased. If the fire were urged hastily, the amber would swell up, and rise in its whole substance into the receiver, without undergoing the required decomposition or separation of its parts. When sand or similar intermedia are mixed with it, it is less subject to this rarefaction, and the fire may be raised somewhat more expeditiously; though this little advantage is perhaps more than counterbalanced by the room which the sand takes up in the retort.

Our chemists generally leave the receiver unlosed, that it may be occasionally removed as the salt rises and concretes in the neck of the retort; from whence it is every now and then scraped out to prevent the oil from carrying it down into the receiver. When a gross thick oil begins to arise, and no more salt appears, the distillation is stopped, though it might perhaps be continued longer to advantage.

Mr Pott informs us (in a curious dissertation on the salt of amber, published in the ninth volume of the Memoirs of the Academy of Sciences of Berlin), that the Prussian workmen, who prepare large quantities of this salt for exportation, from cuttings and small pieces of amber, perform the distillation without any intermediate, and in an open fire: that sweeping out the salt from the neck of the retort being found too troublesome, they suffer the oil to carry it down into the receiver, and afterwards separate it by means of bibulous paper, which imbibes the oil, and leaves the salt dry; which paper is afterwards squeezed and distilled; that they continue the distillation till all that can be forced... forced over has arisen, taking care only to catch the last thick oil in a separate receiver; and that from this they extract a considerable quantity of salt, by shaking it in a strong vessel with three or four fresh portions of hot water, and evaporating and crystallizing the filtered waters.

The spirit of amber, so called, is no more than a solution of a small proportion of the salt in phlegm or water; and therefore is very properly employed for dissolving the salt in order to its crystallization.

The salt, freed from as much of the oil as spongy paper will imbibe, retains so much as to appear of a dark brown colour. Mr Pott says, the method he has found to succeed best, and with least loss, is, to dissolve the salt in hot water, and put into the paper, through which the solution is to be filtered, a little cotton slightly moistened with oil of amber; this, he says, retains a good deal of the oil of the salt, and the solution passes through the more pure. The liquor being evaporated with a very gentle fire, as that of a water-bath, and set to shoot, the first crystals prove transparent, with a slight yellowish tinge; but those which follow are brown, oily, and bitter, and are therefore to be further depurated in the same manner. The whole quantity of crystals amounts to about one-thirtieth of the weight of the crude amber employed. By sublimation from sea-salt, as directed in former editions of the Edinburgh pharmacopoeia, the salt is thought to be more perfectly and more expeditiously purified: Mr Pott objects to sublimation, that a part of the salt is decomposed by it, a coaly matter being left behind, even though the salt was previously purified by crystallization: it may be presumed, however, that this coal proceeds rather from the burning of some remains of the oily matter, than from the decomposition of any part of the true salt.

Pure salt of amber has a penetrating, subastringent, acid taste. It dissolves both in water and in rectified spirit; though not readily in either, and scarcely at all in the latter without the assistance of heat: of cold water in summer, it requires for its solution about twenty times its own weight; of boiling water only about twice its weight. Exposed in a glass vessel, to a heat little greater than that of boiling water, it first melts, then rises in a white fume, and concretes again in the upper part of the glass into fine white flakes, leaving, unless it was perfectly pure, a little coaly matter behind. It effervesces with alkalis both fixed and volatile, and forms with them neutral compounds much resembling those composed of the same alkalis and vegetable acids. Mixed with acid liquors, it makes no sensible commotion. Ground with fixed alkaline salts, it does not exhale any urinous odour. By these characters, it is conceived this salt may be readily distinguished from all the other matters that have been mixed with or vended for it. With regard to its virtue, it is accounted aperient, diuretic, and, on account of its retaining some portion of the oil, antihysteric: Boerhaave gives it the character of diureticorum et antihystericorum princeps. Its great price, however, has prevented its coming much into use; and perhaps its real virtues are not equal to the opinion generally entertained of them.

The rectified oil has a strong bituminous smell, and a pungent acid taste. Given in a dose of ten or twelve drops, it heats, stimulates, and promotes the preparatory secretions: It is chiefly celebrated in hysterical disorders, and in deficiencies of the uterine purgations. Sometimes it is used externally, in liniments for weak or paralytic limbs and rheumatic pains. This oil differs from all those of the vegetable kingdom, and agrees with the mineral petrolea, in not being soluble either in its rectified or unrectified state, by spirit of wine, fixed alkaline lixivia, or volatile alkaline spirits; the oil, after long digestion or agitation, separating as freely as common oil does from water.

Oil of wine. L.

Take alcohol, vitriolic acid, of each one pint. Mix them by degrees, and distil; taking care that no black foam passes into the receiver. Separate the oily part of the distilled liquor from the volatile vitriolic acid. To the oily part add as much water of pure kali as is sufficient to take away the sulphurous smell; then distil the ether with a gentle heat. The oil of wine remains in the retort, floating on the watery liquor, from which it is to be separated.

Some caution is requisite in mixing the two liquors, that the consequent heat and ebullition, which would not only dissipate a part of the mixture, but hazard the breaking of the vessel and the hurt of the operator, may be avoided. The securest way is to add the vitriolic acid to the spirit of wine by a little at a time, waiting till the first addition be incorporated before another quantity be put in. By this, the ensuing heat is inconsiderable, and the mixture is effected without inconvenience.

Essential oil of wormwood. Ross.

Let the fresh leaves of wormwood slightly dried be macerated with a sufficient quantity of water, and then subject to distillation; and let the oil which comes over be separated from the water which accompanies it.

This is one of the more ungrateful oils; it smells strongly of the wormwood, and contains its particular nauseous taste, but has little or nothing of its bitterness, this remaining entire in the decoction left after the distillation: its colour, when drawn from the fresh herb, is a dark green; from the dry, a brownish yellow. This oil is recommended by Hoffman as a mild anodyne in spasmodic contractions; for this purpose, he directs a dram of it to be dissolved in an ounce of rectified spirit of wine, and seven or eight drops of the mixture taken for a dose in any convenient vehicle. Boerhaave greatly commends, in tertian fevers, a medicated liquor composed of about seven grains of this oil ground first with a dram of sugar, then with two drams of the salt of wormwood, and afterwards dissolved in six ounces of the distilled water of the same plant: two hours before the fit is expected, the patient is to bathe his feet and legs in warm water, and then to drink two ounces of the liquor every quarter of an hour till the two hours are expired: by this means, he says, all cases of this kind are generally cured with ease and safety, provided there be no chirrosis or suppuration. The oil of wormwood is employed chiefly as a vermifuge; and for this purpose is sometimes applied both externally to the belly, and taken taken internally; it is most conveniently exhibited in the form of pills, into which it may be reduced by mixing it with crumb of bread.

In the same manner with the oil of wormwood, the following oils, mentioned on the authority of the pharmacopoeia Rossica, are also directed to be prepared.

**Essential oil of orange-skins.** Roff.

**Essence of lemons.**

Of these essential oils, as existing in a separate state in the growing vegetable, we have already offered some observations. They are obtained in a very pure state by distillation. They are now rejected from our pharmacopoeias, being employed rather as perfumes than as medicines. This is particularly the case with the essence of lemons, which is a pleasant oil, of a fine smell, very nearly as agreeable as that of the fresh peel; it is one of the lightest and most volatile essential oils we have, perfectly limpid, and almost colourless. It is taken in doses of two or three drops, as a cordial, in weaknesses of the stomach, &c., though more frequently used as a perfume. It gives a fine flavour to the officinal volatile aromatic spirit of the Edinburgh college, or the compound spirit of ammonia, as it is now styled by that of the London; and it may be remarked, that it enters the formula of both colleges, although neither of them has given it a place among their preparations, probably as it is one of those articles which the apothecary rarely prepares for himself. When soap is given in the form of pills, by the addition of a few drops of this oil they are thought to fit more easily on the stomach.

**Essential oil of cloves.** Roff.

This oil is so ponderous as to sink in water, and is not easily elevated in distillation: if the water which comes over be returned on the remaining cloves, and the distillation repeated, some more oil will generally be obtained, though much inferior in quality to the first. The oil of cloves is usually described as being "in taste excellently hot and fiery, and of a gold yellow colour," (Boerh. proceff.). Such indeed is the composition which we receive under this name from Holland; but the genuine oil of cloves is one of the milder oils; it may be taken with great safety (duly diluted) to the quantity of 10 or 12 drops or more. Nor is its colour at all yellow, unless it has been long and carelessly kept, or distilled by too violent a fire: when in perfection, it is limpid and colourless, of a pleasant, moderately warm, and pungent taste, and a very agreeable smell, much resembling that of the spice itself. The Dutch oil of cloves contains a large quantity of expressed oil, as evidently appears upon examining it by distillation. This, however, cannot be the addition to which it owes its acrimony. A mean proportion of a resinous extract of cloves communicates to a large one of oil a deep colour, and a great degree of acrimony.

**Essential oil of camomile.** Roff.

An oil of camomile had formerly a place in our pharmacopoeias made by infusion of the recent plant, and its flowers in olive oil; and again separating it by pressure after impregnating it with the active parts of the plant by heat. This, however, was intended only for external application; but the essential oil is meant to be used internally.

It is a very pungent oil, of a strong not ungrateful smell, resembling that of the flowers; its colour is yellow, with a cast of greenish or brown. It is sometimes given in the dose of a few drops, as a carminative, in hysterical disorders, and likewise as a vermifuge: it may be conveniently made into pills with crumb of bread.

**Oil of cinnamon.** Roff.

This valuable oil is extremely hot and pungent, of a most agreeable flavour, like that of the cinnamon itself. In cold languid cases, and debilities of the nervous system, it is one of the most immediate cordials and restoratives. The dose is one, two, or three drops; which must always be carefully diluted by the mediation of sugar, &c.; for so great is the pungency of this oil, that a single drop let fall upon the tongue, undiluted, produces, as Boerhaave observes, a gangrenous effusion. In the distillation of this oil, a smart fire is required; and the low head, with a channel round it, recommended for the distillation of the less volatile oils, is particularly necessary for this, which is one of the least volatile, and which is afforded by the spice in exceeding small quantity. The distilled water retains no small portion of the oil; but this oil being very ponderous, great part of it subsides from the water, on standing for two or three weeks in a cool place.

**Essential oil of fennel-seeds.** Roff.

The oil obtained from sweet fennel-seeds is much more elegant and agreeable than that of the common fennel. It is one of the mildest of these preparations; it is nearly of the same degree of warmth with that of aniseeds; to which it is likewise similar in flavour, though far more grateful. It is given from two or three drops to ten or twelve, as a carminative, in cold indispositions of the stomach; and in some kinds of coughs for promoting expectoration.

**Essential oil of rhodium.** Roff.

This oil is extremely odoriferous, and principally employed as a perfume in scenting pomatums, and the like. Custom has not as yet received any preparation of this elegant aromatic wood into internal use among us.

**Essential oil of mace.** Roff.

The essential oil of mace is moderately pungent, very volatile, and of a strong aromatic smell, like that of the spice itself. It is thin and limpid, of a pale yellowish colour, with a portion of thicker and darker coloured oil at the bottom. This oil, taken internally to the extent of a few drops, is celebrated in vomiting, fingultus, and colic pains; and in the same complaints it has also been advised to be applied externally to the umbilical region. It is, however, but rarely to be met with in the shops.

**Essential oil of marjoram.** Roff.

This oil is very hot and penetrating, in flavour not near so agreeable as the marjoram itself; when in perfection, it is of a pale yellow colour; by long keeping, it turns reddish: if distilled with too great a heat, it rises of this colour at first. It is supposed by some to be peculiarly serviceable in relaxations, obstructions, and mucous discharges of the uterus: the dose is one or two drops.

**Essential oil of nutmegs.** Ross.

The essential oil of nutmegs possesses the flavour and aromatic virtues of the spice in an eminent degree. It is similar in quality to the oil of mace, but somewhat less grateful.

**Essential oil of rue.** Ross.

The oil of rue has a very acrid taste, and a penetrating smell, resembling that of the herb, but rather more unpleasant. It is sometimes made use of in hysterical disorders and as an anthelmintic; and also in epilepsies proceeding from a relaxed state of the nerves.

Rue yields its oil very sparingly. The largest quantity is obtained from it when the flowers are ready to fall off, and the seeds begin to show themselves; suitable maceration, previous to the distillation, is here extremely necessary.

**Essential oil of savory.** Ross.

Savory yields on distillation a small quantity of essential oil, of great subtilty and volatility; and it is unquestionably an active article, but among us it is not employed in medicine.

**Essential oil of tanzy.** Ross.

Tanzy yields on distillation an oil of a greenish colour inclining to yellow. It smells strongly of the herb, and possesses at least its aromatic property in a concentrated state.

**Oil of wax.** Dan.

Melt yellow bees-wax with twice its quantity of sand, and distil in a retort placed in a sand-furnace. At first an acid liquor rises, and afterwards a thick oil, which sticks in the neck of the retort, unless it be heated by applying live coal. This may be rectified into a thin oil, by distilling it several times, without addition, in a sand-heat.

Boerhaave directs the wax, cut in pieces, to be put into the retort first, so as to fill one half of it; when as much sand may be poured thereon as will fill the remaining half. This is a neater, and much less troublesome way, than melting the wax, and mixing it with the sand before they are put into the retort. The author above-mentioned highly commends this oil against roughness and chaps of the skin, and other like purposes—the college of Strasbourg speak also of it being given internally, and say it is a powerful diuretic (*ingens diureticum*) in doses from two to four or more drops; but its disagreeable smell has prevented its coming into use among us.

The number of essential oils which have now a place in the London and Edinburgh pharmacopoeias, and likewise in the foreign ones of modern date, is much less considerable than formerly; and perhaps those still retained afford a sufficient variety of the more active and useful oils. Most of the oils mentioned above, particularly those which have a place in the London and Edinburgh pharmacopoeias, are prepared by our chemists in Britain, and are easily procurable in a tolerable degree of perfection; but the oils from the more expensive spices, though still introduced among the preparations in the foreign pharmacopoeias, are, when employed among us, usually imported from abroad.

There are frequently so much adulterated, that it is not an easy matter to meet with such as are fit for use. Nor are these adulterations easily discoverable. The grossest abuses, indeed, may be readily detected: thus, if the oil be mixed with spirit of wine, it will turn milky on the addition of water; if with expressed oils, rectified spirit will dissolve the essential, and leave the other behind; if with oil of turpentine, on dipping a piece of paper in the mixture, and drying it with a gentle heat, the turpentine will be betrayed by its smell. But the more subtle arts have contrived other methods of sophistication, which elude all trials of this kind.

Some have looked upon the specific gravity of oils as a certain criterion of their genuineness; and accordingly we have given a table of the gravity of several. This, however, is not to be absolutely depended on: for the genuine oils, obtained from the same subjects, often differ in gravity as much as those drawn from different ones. Cinnamon and cloves, whose oils usually sink in water, yield, if slowly and warily distilled, an oil of great fragrancy, which is nevertheless specifically lighter than the aqueous fluid employed in the distillation of it; while, on the other hand, the last runnings of some of the lighter oils prove sometimes too ponderous as to sink in water.

As all essential oils agree in the general properties of solubility in spirit of wine, indissolubility in water, miscibility with water by the intervention of certain intermediaries, volatility in the heat of boiling water, &c., it is plain that they may be variously mixed with each other, or the dearer sophisticated with the cheaper, without any possibility of discovering the abuse by any trials of this kind. And indeed it would not be of much advantage to the purchaser, if he had infallible criteria of the genuineness of every individual oil. It is of as much importance that they be good, as that they be genuine; for genuine oils, from inattentive distillation and long and careless keeping, are often weaker both in smell and taste than the common sophisticated ones.

The smell and taste seem to be the only certain tests of which the nature of the thing will admit. If a bark should have in every respect the appearance of good cinnamon, and should be proved indisputably to be the genuine bark of the cinnamon-tree; yet if it want the cinnamon flavour, or has it but in a low degree, we reject it; and the case is the same with the oil. It is only from use and habit, or comparisons with specimens of known quality, that we can judge of the goodness either of the drugs themselves or of their oils.

Most of the essential oils, indeed, are too hot and pungent to be tasted with safety; and the smell of the subject is so much concentrated in them, that a small variation in this respect is not easily distinguished; but we can readily dilute them to any assignable degree. A drop of the oil may be dissolved in spirit of wine, or received on a bit of sugar, and dissolved by that intermediate in water. The quantity of liquor which it thus impregnates with its flavour, or the degree of flavour We shall here subjoin the result of some experiments, showing the quantity of essential oil obtained from different vegetables, reduced into the form of a table. The first column contains the names of the respective vegetable substances; the second, the quantity of each which was submitted to the distillation; and the third, the quantity of oil obtained. In every other part of this article, where pound weights are mentioned, the Troy pound of 12 ounces is meant: but these experiments having been all made by a pound of 16 ounces, it was thought expedient to set down the matter of fact in the original weights: especially as the several materials, in the large quantity commonly required for the distillation of oils, are purchased by weights of the same kind. But to remove any ambiguity which might arise from hence, and to enable the reader to judge more readily of the produce, a reduction of the weights is given in the next column; which shows the number of parts of each of the subjects from which one part of oil was obtained. To each article is affixed the author's name from whom the experiment was taken. The different distillations of one subject, several of which are inserted in the table, show how variable the product of oil is, and that the exotic spices, as well as our indigenous plants, do not always contain the same proportion of this active principle; though it must be observed, also, that part of the differences may probably arise from the operation itself having been more or less carefully performed.

### TABLE of the Quantity of Essential Oil obtained from different Vegetables.

| Vegetable | Quantity | Yielded of essential oil | |----------------------------|----------|--------------------------| | Agallochum wood | 10 lb. | 4 dra. | | Angelica root | 1 lb. | 1 dra. | | Aniseed | 1 lb. | 4 dra. | | Aniseed | 3 lb. | 1 oz. | | Aniseed | 4 lb. | 1 oz. | | Asafoetida | 4 oz. | 1 dra. | | Calamus aromaticus | 50 lb. | 2 oz. | | Calamus aromaticus | 1 lb. | 2 scr. | | Caraway seeds | 4 lb. | 2 oz. | | Caraway seeds | 2 lb. | 9 dra. | | Caraway seeds | 1 cwt. | 83 oz. | | Caroline thistle roots | 1 lb. | 2½ scr. | | Cardamom seeds | 1 oz. | 1 scr. | | Carrot seeds | 2 lb. | 1½ dra. | | Casscarilla | 1 lb. | 1 dra. | | Camomile flowers | 1 lb. | 30 gra. | | Common camomile flowers | 6 lb. | 5 dra. | | Wild camomile flowers | 1 lb. | 20 gra. | | Wild camomile flowers | 6 lb. | 2½ dra. | | Chervil leaves, fresh | 9 lb. | 30 gra. | | Cedar-wood | 1 lb. | 2 dra. | | Cinnamon | 1 lb. | 1 dra. | | Cinnamon | 1 lb. | 2½ scr. | | Cinnamon | 4 lb. | 6 dra. | | Cinnamon | 1 lb. | 2 dra. | | Clary seeds | 4 lb. | 8 scr. | | Clary in flower, fresh | 130 lb. | 3½ oz. | | Cloves | 1 lb. | 1½ oz. | | Cloves | 2 lb. | 2½ oz. | | Copaiba balsam | 1 lb. | 5 oz. | | Copaiba balsam | 1 lb. | 6 oz. | | Cummin-feed | 1 bush | 8 oz. | | Dicamnus Creticus | 1 lb. | 21 oz. | | Dill-feed | 4 lb. | 30 gra. | | Elecampane root | 2 lb. | 2 oz. | | Eleo | 1 lb. | 3½ scr. | | Fennel-feed, common | 2 oz. | 1 oz. | | Fennel-feed, sweet | 1 bush | 1 scr. | | Galangal root | 1 lb. | 18 oz. | | Garlic root, fresh | 2 lb. | 1 oz. | | Ginger | 1 lb. | 1 oz. | | Horse-radish root, fresh | 8 oz. | 15 gra. | | Hyssop leaves | 2 lb. | 1½ dra. |

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**Note:** The quantities are given in Troy pounds (12 ounces) and drams (oz.), scruples (scr.), and grains (gra.). | Item | Quantity | Unit | Yielded from Essential Oil | |-------------------------------|----------|--------|-----------------------------| | Hyssop leaves | 1 lb | | | | Hyssop leaves | 1 lb | | | | Hyssop leaves, fresh | 2 cwt | | | | Hyssop leaves, fresh | 10 lb | | | | Hyssop leaves, fresh | 30 lb | | | | Juniper-berries | 8 lb | | | | Juniper-berries | 3 oz | | | | Juniper-berries | 3 dra | | | | Lavender in flower, fresh | 48 lb | | | | Lavender in flower, fresh | 30 lb | | | | Lavender flowers, fresh | 2 lb | | | | Lavender flowers, dried | 4 lb | | | | Lavender flowers, dried | 2 lb | | | | Lavender flowers, dried | 4 lb | | | | Broad-leaved lavender flowers, dry | 4 lb | | | | Lovage root | 1 lb | | | | Mace | 1 lb | | | | Marjoram in flower, fresh | 81 lb | | | | Marjoram in flower, fresh | 13½ lb | | | | Marjoram in flower, fresh | 34 lb | | | | Marjoram leaves, fresh | 18½ lb | | | | Marjoram leaves, dried | 4 lb | | | | Maiterwort root | 1 lb | | | | Milfoil flowers, dried | 14 lb | | | | Mint in flower, fresh | 6 lb | | | | Mint-leaves, dried | 4 lb | | | | Peppermint, fresh | 4 lb | | | | Myrrh | 1 lb | | | | Nutmegs | 1 lb | | | | Nutmegs | 1 lb | | | | Nutmegs | 1 lb | | | | Parsley seeds | 2 lb | | | | Parsley leaves, fresh | 238 lb | | | | Parsnip seeds | 8 lb | | | | Pennyroyal in flower, fresh | 13 lb | | | | Black pepper | 2 lb | | | | Black pepper | 1 lb | | | | Black pepper | 1 lb | | | | Black pepper | 6 lb | | | | Pimento | 1 oz | | | | Rhodium wood | 1 lb | | | | Rhodium wood | 1 lb | | | | Rhodium wood | 1 lb | | | | Rhodium wood | 1 lb | | | | Rosemary in flower | 1 cwt | | | | Rosemary leaves | 1 lb | | | | Rosemary leaves | 1 lb | | | | Rosemary leaves | 3 lb | | | | Rosemary leaves | 1 lb | | | | Rosemary leaves | 1 lb | | | | Rosemary leaves | 70 lb | | | | Rosemary leaves, fresh | 100 lb | | | | Rosemary leaves, fresh | 100 lb | | | | Rosemary leaves, fresh | 12 lb | | | | Rue | 10 lb | | | | Rue | 10 lb | | | | Rue | 4 lb | | | | Rue | 60 lb | | |

For that one part of oil was obtained from:

| Item | Quantity | Unit | Yielded from Essential Oil | |-------------------------------|----------|--------|-----------------------------| | Carth. | 85 | | | | Carth. | 64 | | | | Lewis. | 597 | | | | Lewis. | 427 | | | | Lewis. | 427 | | | | Hoff. | 42½ | | | | Carth. | 42½ | | | | Lewis. | 64 | | | | Lewis. | 72 | | | | Lewis. | 403 | | | | Hoff. | 64 | | | | Lewis. | 32 | | | | Hoff. | 32 | | | | Hoff. | 21½ | | | | Hoff. | 64 | | | | Carth. | 128 | | | | Carth. | 25½ | | | | Neum. | 21½ | | | | Carth. | 347 | | | | Lewis. | 493 | | | | Lewis. | 302 | | | | Lewis. | 592 | | | | Hoff. | 64 | | | | Neum. | 256 | | | | Neum. | 448 | | | | Neum. | 177 | | | | Hoff. | 42½ | | | | Hoff. | 170½ | | | | Hoff. | 64 | | | | Neum. | 42½ | | | | Hoff. | 16 | | | | Hoff. | 16 | | | | Geoff. | 32 | | | | Neum. | 21½ | | | | Sala. | 25½ | | | | Carth. | 256 | | | | Carth. | 1904 | | | | Carth. | 512 | | | | Carth. | 277 | | | | Carth. | 42½ | | | | Carth. | 82 | | | | Carth. | 96 | | | | Heijler. | 128 | | | | Geoff. | 256 | | | | Neum. | 16 | | | | Neum. | 42½ | | | | Neum. | 64 | | | | Sala. | 42½ | | | | Sala. | 121 | | | | Carth. | 128 | | | | Carth. | 82 | | | | Lewis. | 224 | | | | Sala. | 64 | | | | Carth. | 42½ | | | | Sala. | 121 | | | | Carth. | 128 | | | | Carth. | 82 | | | | Lewis. | 224 | | | | Tachen. | 3200 | | | | Homb. | 1000 | | | | Hoff. | 768 | | | | Hoff. | 640 | | | | Hoff. | 320 | | | | Hoff. | 512 | | | | Hoff. | 507 | | |

Rue **Part II**

**Preparations and Compositions**

| Rue with the seeds | 72 lb. | |-------------------|-------| | Saffron | 1 lb. | | Sage leaves | 1 lb. | | Sage in flower, fresh | 34 lb. | | Sage of virtue in flower | 27 lb. | | Sage of virtue in flower | 8 lb. | | Sassafras | 6 lb. | | Sassafras | 6 lb. | | Savin | 2 lb. | | Saunders, yellow | 1 lb. | | Smallage seeds | 1 lb. | | Stechas in flower, fresh | 5½ lb. | | Thyme in flower, fresh | 2 cwt. | | Thyme in flower, dry | 3¼ lb. | | Lemon thyme in flower, fresh | 51 lb. | | Lemon thyme in flower, fresh | 98 lb. | | Lemon thyme, a little dried | 104 lb. | | Wormwood leaves, dry | 4 lb. | | Wormwood leaves, dry | 18 lb. | | Wormwood leaves, dry | 25 lb. | | Zedoary | 1 lb. |

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**Chap. VII. Salts.**

**Diluted or weak vitriolic acid. L.**

Take of vitriolic acid, one ounce by weight; distilled water, 8 ounces by weight. Mix them by degrees.

**Weak vitriolic acid, commonly called weak spirit of vitriol. E.**

Take of vitriolic acid, one part; water, seven parts. Mix them.

In the former editions of our pharmacopeias, directions were given for the preparation of the vitriolic acid by the apothecary himself, under the heads of spirit and oil of vitriol, spirit or oil of sulphur by the bell, &c.; but as it is now found that all these modes are expensive, and that this acid may be furnished at a cheaper rate from the trading chemists preparing it on a large scale, it is with propriety that both colleges have now rejected it from the preparations, and introduced it only into the list of the materia medica.

When, however, it is of the degree of concentration there required, it can be employed for very few purposes in medicine. The most simple form in which it can be advantageously employed internally, is that in which it is merely diluted with water: and it is highly proper that there should be some fixed standard in which the acid in this state should be kept. It is, however, much to be regretted, that the London and Edinburgh colleges have not adopted the same standard with respect to strength: for in the one, the strong acid constitutes an eighth; and in the other, only a ninth of the mixture. The former proportion, which is that of the Edinburgh college, we are inclined to prefer, as it gives exactly a dram of acid to the ounce; but the dilution by means of distilled water, which is directed by the London, is preferable to spring-water; which, even in its purest state, is rarely free from impregnations in part affecting the acid.

The acid of vitriol is the most ponderous of all the liquids we are acquainted with, and the most powerful of the acids. If any other acid be united with a fixed alkaline salt or earth, on the addition of the vitriolic, such acid will be dislodged, and arise on applying a moderate heat, leaving the vitriolic in possession of the alkali; though without this addition it would not yield to the most vehement fire. Mixed with water, it instantly creates great heat, insomuch that glass vessels are apt to crack from the mixture, unless it be very slowly performed: exposed to the air, it imbibes moisture, and soon acquires a remarkable increase of weight. In medicine, it is employed chiefly as subservient to other preparations: it is also frequently mixed with juleps and the like, in such quantity as will be sufficient to give the liquor an agreeable tartness, and it then is a cooling antiseptic, a refrigerant, and a stomachic.

It is particularly useful for allaying inordinate actions of the stomach, when under the form of pinguis tus or vomiting. For its medical properties, see Acids and Vitriol.

**Nitrous acid. L.**

Take of purified nitre, by weight, 60 ounces; vitriolic acid, by weight, 29 ounces. Mix and distill.

The specific gravity of this is to the weight of distilled water as 1550 to 1000.

**Nitrous acid, commonly called Glauber's spirit of nitre. E.**

Take of purest nitre, bruised, two pounds; vitriolic acid, one pound. Having put the nitre into a glass retort, pour on it the spirit; then distill in a sand-heat, gradually increasing the fire, till the sand-pot becomes of a dull red colour.

Here the vitriolic acid expels the nitrous, in red corrosive vapours, which begin to issue immediately on mixture; and which the operator ought cautiously to avoid. A pound of acid of vitriol is sufficient to expel all the acid from about two pounds of nitre, not from more: some direct equal parts of the two. The spirit, in either case, is in quality the same; the difference, in this respect, affecting only the residuum. If two parts of nitre be taken to one of vitriolic acid, the remaining alkaline basis of the nitre is completely saturated with the vitriolic acid; and the result is a neutral salt, the same with vitriolated tartar, as we shall If more nitre be used, a part of the nitre in substance will remain blended with this neutral salt; if less nitre, it cannot afford alkali enough to saturate the vitriolic acid, and the residuum will not be a neutral salt, but a very acid one. In this last case there is one convenience; the acid salt being readily soluble in water, so as to be got out without breaking the retort, which the others are not.

**Diluted or weak nitrous acid. L.**

Take of nitrous acid, distilled water, each one pound. Mix them.

**Weak nitrous acid. E.**

Take of nitrous acid, water, equal weights. Mix them, taking care to avoid the noxious vapours.

In the old editions both of the London and Edinburgh pharmacopoeias, directions were given for the preparation of aquafortis simplex and duplex; but these were no more than different forms of preparing an impure nitrous acid, unfit for medical purposes. They are therefore, with propriety, superseded by the more simple formulae of nitrous acid and diluted or weak nitrous acid, mentioned above. In making the diluted acid, distilled water is preferable to common water.

The vapour separated during the mixing of nitrous acid and water, is the permanently elastic fluid called nitrous acid air, which is deleterious to animal life.

The acid of nitre is next in strength to the vitriolic, and dislodges all others from alkaline salts or earths. It differs from all the other acids in deslagrating with inflammable matters: if a solution of any inflammable substance, as hartshorn, &c., in this acid, be set to evaporate, as soon as the matter approaches to dryness, a violent detonation ensues. The chief use of this acid is as a menstruum for certain minerals, and as the basis of some particular preparations to be mentioned hereafter. It has been given likewise, diluted with any convenient vehicle, as a diuretic, from 10 to 50 drops.

**Muriatic acid. L.**

Take of dry sea-salt, 10 pounds; vitriolic acid, six pounds; water, five pounds. Add the vitriolic acid first mixed with the water by degrees, to the salt; then distil.

The specific gravity of this acid is to distilled water as 1170 to 1000.

**Muriatic acid, commonly called spirit of sea-salt. E.**

Take of sea-salt, two pounds; vitriolic acid, water, each one pound. Let the salt be first put into a pot, and brought to a red heat, that the oily impurities may be consumed; then put it into the retort. Next mix the acid with the water, and when the mixture has cooled, pour it upon the salt. Lastly, distil in a sand heat with a middling heat, as long as any acid comes over.

The marine, or muriatic acid, arises, not in red fumes like the nitrous, but in white ones. The addition of water is more necessary here than in the foregoing process; the marine vapours being so volatile, as scarcely to condense without some adventitious humidity. The acid of vitriol is most conveniently mixed with the water in an earthen or stone-ware vessel; for unless the mixture be made exceedingly slow, it grows so hot as to endanger breaking a glass one.

The spirit of sea-salt is the weakest of the mineral acids, but stronger than any of the vegetable: it requires a greater fire to distil it than that of nitre, yet it is more readily dissipated by the action of the air. It is used chiefly as a menstruum for the making of other preparations; sometimes, likewise, it is given, properly diluted, as an antiphlogistic, aperient, and diuretic, from 10 to 60 or 70 drops.

**Distilled vinegar.**

Take of vinegar five pints. Distil with a gentle fire, in glass vessels, so long as the drops fall free from empyreuma. L.

Let eight pounds of vinegar be distilled in glass vessels with a gentle heat. Let the two first pounds that come over be thrown away as containing too much water; let four pounds next following be reserved as the distilled vinegar. What remains is a still stronger acid, but too much acted on by the heat. E.

This process may be performed either in a common still with its head, or in a retort. The better kinds of wine-vinegar should be used: those prepared from malt liquors, however fine and clear they may seem to be, contain a large quantity of a viscous substance, as appears from the slimy smell and ropiness to which they are very much subject: this not only hinders the acid parts from rising freely, but likewise is apt to make the vinegar boil over into the recipient, and at the same time dispose it to receive a disagreeable impression from the fire. And indeed, with the best kind of vinegar, if the distillation be carried on to any great length, it is extremely difficult to avoid an empyreuma. The best method of preventing this inconvenience is, if a retort be used, to place the sand but a little way up its sides, and when somewhat more than half the liquor is come over, to pour on the remainder a quantity of fresh vinegar equal to the liquor drawn off. This may be repeated three or four times; the vinegar supplied at each time being previously heated. The addition of cold liquor would not only prolong the operation, but also endanger the breaking of the retort. If the common still be employed, it should likewise be occasionally supplied with fresh vinegar in proportion as the spirit runs off; and this continued until the process can be conveniently carried no farther: the distilled spirit must be rectified by a second distillation in a retort or glass alembic; for although the head and receiver be of glass or stone ware, the acid will contract a metallic taint from the pewter worm.

The residuum of this process is commonly thrown away as useless, although, if skilfully managed, it might be made to turn to good account; the moist acid parts of the vinegar still remaining in it. Mixed with about three times its weight of fine dry sand, and committed to distillation in a retort, with a well-regulated fire, it yields an exceeding strong acid spirit, together with an empyreumatic oil, which taints the spirit with a disagreeable odour. This acid is nevertheless, without any rectification, better for some purposes (as a little of it will go a great way) than the pure spirit; particularly for making the diuretic or acetated kali of the London college; for there the oily matter, on which its ill flavour depends, is burnt out by the calcination.

The spirit of vinegar is a purer and stronger acid than vinegar itself, with which it agrees in other respects. (See Vinegar). Their principal difference from the mineral acid consists in their being milder, less stimulating, less disposed to affect the kidneys and promote the urinary secretions, or to coagulate the animal juices. The matter left after the distillation in glass vessels, though not used in medicine, would doubtless prove a serviceable detergent sebaceous acid; and in this light stands recommended by Boerhaave.

Concentrated vinegar. Suec.

Let white wine vinegar be frozen in a wooden vessel in cold winter weather; and let the fluid separated from the ice be preserved for use. It may be considered as sufficiently strong, if one dram of it be capable of saturating a scruple of the fixed vegetable alkali.

This is a very easy mode for obtaining the acid of vinegar in a concentrated state, and freed from a considerable portion of its water. But at the same time we do not thus obtain the acid either so much concentrated, or in so pure a state as by the following process.

Acetous acid. L.

Take of verdigris, in coarse powder, two pounds. Dry it perfectly by means of a water-bath saturated with sea-salt; then distil it in a sand-bath, and after that distil the liquor. Its specific gravity is to that of distilled water as 1050 to 1000.

By this process, it may be readily concluded that we obtain the acetous acid in its most concentrated state, and with the least admixture of water. And after the re-distillation, it may also be supposed that it will be free from all mixture of the copper. But the internal use of it has been objected to by some, on the supposition that it may still retain a portion of the metal; and hitherto it has, we believe, been but little employed.

Crystallized acid of tartar. Suec.

Take of prepared chalk, frequently washed with warm water, two pounds; spring water, 32 pounds. After slight boiling, by degrees add of cream of tartar 7 pounds, or as much as is sufficient for saturation. Removing the vessel from the fire, let it stand for half an hour, then cautiously pour off the clear liquor into a glass vessel. Wash the residuum or tartarous selenites by pouring water on it three or four times. To this residuum afterwards add of weak vitriolic acid 16 pounds, let it be digested for a day, frequently stirring it with a wooden spatula. After this pour the acid liquor into a glass vessel; but with the residuum mix 16 pounds of spring water; strain it through paper, and again pour water on the residuum till it become insipid. Let the acid liquors mixed together in a glass vessel be boiled to the consistence of a thin syrup; which being strained, must be set apart for the formation of crystals. Let the crystals collected after repeated distillations be dried on paper, and afterwards kept in a dry place.

If before crystallization a little of the infusoriated acid liquor be diluted with four times its quantity of pure water, and a few drops of vinegar of litharge be put into it, a white sediment will immediately be deposited. If a few drops of the diluted nitrous acid be then added, the mixture will become limpid, if the tartarous liquor be pure and entirely free from the vitriolic acid; but if it be not, it will become white. This fault, however, may be corrected, if the acid of tartar be diluted with six pounds of water and a few ounces of the tartarous selenites be added to it. After this it may be digested, strained, and crystallized.

By this process, the acid of tartar may be obtained in a pure solid form. It would, however, be perhaps an improvement of the process, if quicklime were employed in place of chalk. For Dr Black has found that quicklime absorbs the whole of the tartarous acid, and then the supernatant liquor contains only the alkaline part of the tartar; whereas, when chalk is employed, it contains a solution of soluble tartar, the chalk taking up only the superabundant acid. By this method then a greater quantity of tartarous acid might be obtained from the sediment. The tartarous acid has not hitherto been much employed in its pure state. But besides being useful for some purposes in medicine, for which the cream of tartar is at present in use, and where that superabundant neutral may be less proper, there is also reason to suppose, that from the employment of the pure acid, we should arrive at more certainty in the preparation of the antimonium tartarizatum, or tartar emetic, than by employing the cream of tartar, the proportion of acid in which varies very much from different circumstances. The pure acid of tartar might also probably be employed with advantage for bringing other metallic substances to a saline state.

Distilled acid of tartar. Suec.

Let pounded crude tartar be put into a tubulated earthen or iron retort till it fills about two-thirds of it, and let distillation be performed by gradually increasing the heat. Into the recipient, which should be very large, an acid liquor will pass over together with the oil; which being separated from the oil, must again be distilled from a glass retort. If the residuum contained in the earthen or iron retort be diluted with water, strained through paper, and boiled to dryness, it gives what is called the alkali of tartar. If this do not appear white, it may be made so by burning, solution, straining, and evaporation.

This is another mode of obtaining both the acid and alkali of tartar in a pretty pure state; and, as well as the former, it is not unworthy of being adopted into our pharmacopoeias.

Aerated water. Roff.

Let spring water be saturated with the fixed air, or aerial acid, arising from a solution of chalk in vitriolic acid, or in any similar acid. Water may also be impregnated by the fixed air rising from fermenting liquors.

The aerial acid, on which we have already had occasion to to make some observations, besides the great influence which it has as affecting different saline bodies into whose composition it enters, is also frequently employed in medicine, with a view to its action on the human body. The late ingenious Dr Dobson, in his Commentary on Fixed Air, has pointed out many purposes for which it may be usefully employed, and several different forms under which it may be used. But there is no form under which it is at present more frequently had recourse to than that of aerated or mephitic water, as it has often been called. And although not yet received either into the London or Edinburgh pharmacopoeias, it is daily employed in practice, and is we think justly entitled to a place among the saline preparations.

The most convenient mode of impregnating water with the aerial acid, and thus having it in our power to exhibit that acid as it were in a diluted state, is by means of a well known and sufficiently simple apparatus, contrived by that ingenious philosopher Dr Nooth. Such a machine ought, we think, to be kept in every shop for the more ready preparation of this fluid. Water properly impregnated with the aerial acid has an agreeable acidulous taste. It is often employed with great advantage in the way of common drink, by those who are subjected to stomach complaints, and by calculous patients. But, besides this, it furnishes an excellent vehicle for the exhibition of many other medicines.

Besides the simple aerated water, the Pharmacopoeia Rossica contains also an aqua acris fixi martialis, or ferruginous aerated water. This is prepared by suspending iron wires in that water till the water be fully saturated with the metal. And in consequence of this acid, simple water becomes a menstruum both for different metallic and earthy substances. But water in this state may be considered rather as fitted for those purposes for which chalybeates are in use, than as a preparation of the aerial acid.

Salt and oil of amber. L.

Take of amber two pounds. Distil in a sand heat, gradually augmented: an acid liquor, oil, and salt impregnated with oil, will ascend.

On this article we have already offered some observations under the head of Essential Oils. The directions here given by the London college differ chiefly from those of the Edinburgh college formerly mentioned, in no sand being employed: But when care is taken that the sand be pure, it can give no improper impregnation to the medicine, and may prevent some inconveniences in the distillation, particularly that of the amber rising in substance into the receiver.

Purified salt of amber. L.

Take of salt of amber half a pound; distilled water, one pint. Boil the salt in the distilled water, and set aside the solution to crystallize.

Salt of amber, when perfectly pure, is white, of an acid taste, and not ungrateful. It requires, for its solution, of cold water, in summer, about twenty times its weight; and of boiling water about twice its weight; it is scarcely soluble in rectified spirit without the assistance of heat.

It is given as a cooling diuretic in doses of a few grains, and also in hysterical complaints.

Flowers of benzoin.

Take of benzoin, in powder, one pound. Put it into an earthen pot, placed in sand; and, with a slow fire, sublime the flowers into a paper cone fitted to the pot.

If the flowers be of a yellow colour, mix them with white clay, and sublime them a second time. L.

Put any quantity of powdered benzoin into an earthen pot, to which, after fitting it with a large conical paper cap, apply a gentle heat that the flowers may sublime. If the flowers be impregnated with oil, let them be purified by solution in warm water and crystallization. E.

Benzoin, exposed in a retort to a gentle fire, melts, and sends up into the neck white, shining crystalline flowers, which are followed by an oily substance. These flowers, which are at present considered as a peculiar acid, are by some termed acidum benzolicum. On raising the heat a little (a recipient being applied to the neck of the retort), a thin yellowish oil comes over, intermingled with an acid liquor, and afterwards a thick butyraceous substance: this last, liquefied in boiling water, gives out to it a considerable quantity of saline matter (separable by filtration and proper exhalation), which appears in all respects similar to the flowers.

It appears, therefore, that the whole quantity of flowers which benzoin is capable of yielding, cannot be obtained by the above processes, since a considerable portion arises after the time of their being discontinued. The greatest part of the flowers arise with a less degree of heat than what is necessary to elevate the oil; but if the operation be hastily conducted, or if the fire be not exceedingly gentle, the oil will arise along with the flowers, and render them foul. Hence in the way of trade, it is extremely difficult to prepare them of the requisite whiteness and purity; the heat which becomes necessary, when large quantities of the benzoin are employed, being so great as to force over some of the oil along with them.

In order, therefore, to obtain these flowers in perfection, only a small quantity of benzoin should be put into the vessel at a time; and that this may not be any impediment to the requisite dispatch, a number of shallow, flat-bottomed, earthen dishes may be employed, each fitted with another vessel inverted over it, or a paper cone. With these you may fill a sand furnace; having fresh dishes charged in readiness to replace those in the furnace, as soon as the process shall appear finished in them: the residuum of the benzoin should be scraped out of each of the vessels before a fresh parcel be put in.

These flowers, when made in perfection, have an agreeable taste and fragrant smell. They totally dissolve in spirit of wine; and likewise, by the assiduity of heat, in water; but separate again from the latter upon the liquor's growing cold, shooting into saline spicula, which unite together into irregular masses. By the mediation of sugar they remain suspended in cold water, and thus form an elegant balsamic syrup. Some have held them in great esteem as pectoral and sedative. fudorific, in the dose of half a scruple or more; but at present they are rarely used, on account of the offensive oil which, as usually prepared, they are tainted with, and from which a fresh sublimation from tobacco-pipe clay, as formerly practised, did not free them so effectually as might be wished. The observations above related, point out the method of depurating them more perfectly, viz. by solution, filtration, and crystallization.

They enter the composition of the paregoric elixir, or tinctura opii camphorata, as it is now called.

Salt of tartar. E.

Take of tartar, what quantity you please. Roll it up in a piece of moist bibulous paper, or put it into a crucible, and surrounding it with live coals, burn it to a coal; next, having beat this coal, calcine it in an open crucible with a moderate heat, taking care that it do not melt, and continue the calcination till the coal becomes of a white, or at least of an ash colour. Then dissolve it in warm water; strain the liquor through a cloth, and evaporate it in a clean iron vessel; diligently stirring it towards the end of the process with an iron spatula, to prevent it from sticking to the bottom of the vessel. A very white salt will remain, which is to be left a little longer on the fire, till the bottom of the vessel becomes almost red. Lastly, when the salt is grown cold, let it be put up in glass vessels well shut.

Native tartar is a saline substance, compounded of an acid, of a fixed alkali, and of oily, viscous, and colouring matter. The purpose of the above process is, to free it from every other matter but the fixed alkali. From the mistaken notion that tartar was essentially an acid mixed only with impurities, it has been generally supposed that the effect of this operation was the conversion of an acid into an alkali by means of heat. But since Mr Scheele has discovered that the proper matter of tartar, freed from the oily and colouring parts, is really a salt compounded of an acid, which is predominant, and a fixed alkali, we have no farther need of such an obscure theory. The acid of the tartar by this process is dissipated by means of the heat; and the oily, viscous, and colouring matters, are partly dissipated, and partly brought to the state of insoluble earthy matter, easily separable by the future lixiviation from the alkali, wherewith they were loosely combined. But by the last of these processes, something farther is carried on than the separation of the more palpable foreign matters. By allowing the salt, freed from the water of the lixivium, to remain on the fire till the bottom of the vessel become almost red, any oily matter that may still be present seems to be decomposed by the united action of the heat and fixed alkali, forming with a part of the latter, by their reciprocal action, a volatile alkaline salt, which is forthwith discharged in elastic vapours. Besides the complete discharge of the above principles, the remaining fixed alkali also suffers a considerable loss of its fixed air, or aerial acid; with which, when fully saturated, it forms the imperfect neutral salt, denominated by Dr Black mild fixed alkali; on this account it is somewhat caustic, considerably deliquescent, and in proportion to its possessing these properties more or less, it more or less nearly approaches to the state of pure alkali. It is not, however, so effectually deprived of fixed air as to be sufficiently caustic for a number of purposes. Where causticity is not required, the salt thus purified is abundantly fit for most pharmaceutical purposes; but as native tartar generally contains small portions of neutral salts besides the foreign matters already noticed, it is necessary, if we wish to have a very pure alkali for nice operations, to employ crystallization and other means, beside the process here directed.

The white and red sorts of tartar are equally fit for the purpose of making fixed salt; the only difference is, that the white affords a somewhat larger quantity than the other: from 16 ounces of this sort, upwards of four ounces of fixed alkaline salt may be obtained. The use of the paper is to prevent the smaller pieces of the tartar from dropping down into the ash-hole, through the interstices of the coals, upon first injecting it into the furnace.

The calcination of the salt (if the tartar was sufficiently burnt at first) does not increase its strength so much as is supposed: nor is the greenish or blue colour any certain mark either of its strength, or of its having been, as was formerly supposed, long exposed to a vehement fire: for if the crucible be perfectly clean, close covered, and has stood the fire without cracking, the salt will turn out white, though kept melted and reverberated ever so long; while, on the other hand, a slight crack happening in the crucible, or a spark of coal falling in, will in a few minutes give the salt the colour admired. The colour, in reality, is a mark rather of its containing some inflammable matter than of its strength.

The vegetable alkali prepared from tartar has now no place in the London pharmacopoeia, or at least it is included under the following article.

Prepared kali. L.

Take of pot-ash, two pounds; boiling distilled water, three pints. Dissolve and filter through paper; evaporate the liquor till a pellicle appears on the surface; then set it aside for a night, that the neutral salts may crystallize; after which pour out the liquor, and boil away the whole of the water, constantly stirring, lest any salt should adhere to the pot. In like manner is purified impure kali from the ashes of any kind of vegetable. The same salt may be prepared from tartar burnt till it becomes of an ash-colour.

Fixed vegetable alkaline salt purified. E.

Let the fixed alkaline salt, called in English pearl-ashes, be put into a crucible, and brought to a somewhat red heat, that the oily impurities, if there be any, may be consumed; then having beat and agitated it with an equal weight of water, let them be well mixed. After the feces have subsided, pour the ley into a very clean iron pot, and boil to dryness, diligently stirring the salt towards the end of the process, to prevent its sticking to the vessel. This salt, if it hath been rightly purified, though it be very dry, if rubbed with an equal weight of water, may be dissolved into a liquor void of colour or smell.

The potash used in commerce is an alkali mixed with a considerable quantity of remaining charcoal, U u sulphur, sulphur, vitriolated tartar, and oily matter. In the large manufactures, the alkaline part is indeed considerably freed from impurities by mixing the weed-ashes with water, evaporating the clear ley, and burning the reticulum in an oven; but besides that this process is insufficient for the complete separation of the impurities, it also superadds a quantity of stony matter, giving to the alkali the pearl appearance (whence its name), and rendering it altogether unfit for pharmaceutical purposes. By the processes here directed, the alkali is effectually freed from all these heterogeneous matters, excepting perhaps a small proportion of vitriolated tartar, or other neutral salts, which may very generally be neglected. As in the process no after calcination is directed, it is probable that the fixed alkali thus prepared will not prove so caustic, that is to say, is not so considerably deprived of fixed air, as in the process directed for preparing the salt of tartar. It is, however, sufficiently pure for most purposes; and we consider the above process as the most convenient and cheap method of obtaining the vegetable fixed alkali in its mild state.

The purified vegetable alkali has been known in our pharmacopoeias under the different names of salt of wormwood, salt of tartar, &c. But all these being now known to be really the same, the terms, as leading to errors, have been with justice expunged; and it has been a desideratum to discover some short name equally applicable to the whole. The term employed by the Edinburgh college is too long, being rather a description than a name; but to that employed by the London college, Kali, objections have also been made. And it must be allowed, that besides the inconvenience which arises from its being an indeclinable word, the fossile alkali is equally intitled to the same appellation. Besides this, as a considerable portion of the fossile alkali is prepared from burning a vegetable growing on the sea coasts, which has the name of kali, the Kali spinosum of Linne, some apparent contradiction and ambiguity may thence arise. And the London college would perhaps have done better, if they had adopted the term Potash; a name which has been appropriated to this salt by some of the most eminent modern chemists.

The purified potash is frequently employed in medicine, in conjunction with other articles, particularly for the formation of saline neutral draughts and mixtures: But it is used also by itself in doses from three or four grains to 15 or 20; and it frequently operates as a powerful diuretic, particularly when aided by proper dilution. See Pearl-Ash and Pot-ash.

Water of kali. L.

Take of kali, one pound, set it by in a moist place till it be dissolved, and then strain it.

This article had a place in former editions of our pharmacopoeias under the titles of ley of tartar, or oil of tartar per deliquium, &c. It is, however, to be considered as a mere watery solution of the mild vegetable alkali, formed by its attracting moisture from the air; and therefore it is with propriety styled the water of kali.

The solutions of fixed alkaline salts, made by exposing them to a moist air, are generally considered as being purer than those made by applying water directly: for though the salt be repeatedly dissolved in water, filtered, and effused; yet, on being left exposed by the humidity of the air, it will still deposit a portion of earthy matter: but it must be observed, that the exhaled salt leaves always an earthy matter on being dissolved in water, as well as on being deliquated in the air. Whether it leaves more in the one way than in the other, is not determined with precision. The deliquated lixivium is said to contain nearly one part of alkaline salt to three of an aqueous fluid. It is indifferent, in regard to the lixivium itself, whether the white ashes of tartar, or the salt extracted from them, be used; but as the ashes leave a much greater quantity of earth, the separation of the ley proves more troublesome.

The water of kali of the present edition of the London pharmacopoeia, then, may be considered as an improvement of the lixivium tartari of their former edition. But the Edinburgh college, considering this solution as being in no respect different from that made by pure water, have entirely rejected this preparation from their pharmacopoeia, and probably with justice.

Water of pure kali. L.

Take of kali, four pounds; quicklime, six pounds; distilled water, four gallons. Put four pints of water to the lime, and let them stand together for an hour; after which, add the kali and the rest of the water; then boil for a quarter of an hour: suffer the liquor to cool, and strain. A pint of this liquor ought to weigh 16 ounces. If the liquor effervesces with any acid, add more lime.

A preparation similar to this had a place in the former edition of the London pharmacopoeia, under the title of soap-ley. Quicklime, by depriving the mild alkali of its aerial acid, renders it caustic: hence this ley is much more acrimonious, and acts more powerfully as a menstruum of oils, fats, &c., than a solution of the potash alone. The lime should be used fresh from the kiln; by long keeping, even in clothe vessels, it loses its strength: such should be made choice of as is thoroughly burnt or calcined, which may be known by its comparative lightness.

All the instruments employed in this process should be either of wood, earthen ware, or glass: the common metallic ones would be corroded by the ley, so as either to discolour or communicate disagreeable qualities to it. If it should be needful to filter or strain the liquor, care must be taken that the filter or strainer be of vegetable matter: woollen, silk, and that sort of filtering paper which is made of animal substances, are quickly corroded and dissolved by it.

The liquor is most conveniently weighed in a narrow-necked glass bottle, of such a size, that the measure of a wine pint may arise some height into its neck; the place to which it reaches being marked with a diamond. A pint of the common leys of our soap-makers weighs more than 16 ounces: it has been found that their soap-ley will be reduced to the standard here proposed, by mixing it with something less than an equal measure of water.

Although this liquor is indeed pure alkali dissolved in water, yet we are inclined to give the preference to the name employed by the Edinburgh college, as well as to the modes of preparing it, directed in the following formula.

**Cayfic ley. E.**

Take of fresh burnt quicklime, eight ounces; purified fixed vegetable alkaline salt, six ounces. Throw the quicklime, with 28 ounces of warm water, into an iron or earthen vessel. The ebullition and extinction of the lime being perfectly finished, instantly add the alkaline salt; and having thoroughly mixed them, shut the vessel till it cools. Stir the cooled matter, and pour out the whole into a glass funnel, whose throat must be stopped up with a piece of clean rag. Let the upper mouth of the funnel be covered, while the tube of it is inserted into a glass vessel, so that the ley may gradually drop through the rag into that vessel. When it first gives over dropping, pour into the funnel some ounces of water; but cautiously, and in such a manner, that the water shall swim above the matter. The ley will again begin to drop, and the affusion of water is to be repeated in the same manner, until three pounds have dropped, which takes up the space of two or three days; then agitating the superior and inferior parts of the ley together, mix them, and put up the liquor in a well-shut vessel.

If the ley be rightly prepared, it will be void of colour or smell; nor will it raise an effervescence with acids, except perhaps a very slight one. Colour and odour denote the salt not sufficiently calcined; and effervescence, that the quicklime has not been good.

The reasons and propriety of the different steps in the above process will be best understood by studying the theory on which it is founded. The principle of mildness in all alkaline salts, whether fixed or volatile, vegetable or fossil, is very evidently fixed air, or the aerial acid: But as quicklime has a greater attraction for fixed air than any of these salts, so if this substance be presented to any of them, they are thereby deprived of their fixed air, and forthwith become caustic. This is what precisely happens in the above processes. The propriety of closely shutting the vessels through almost every step of the operation, is sufficiently obvious; viz. to prevent the absorption of fixed air from the atmosphere, which might defeat our intentions. When only a piece of cloth is put into the throat of the funnel, the operation is much more tedious, because the pores of the cloth are soon blocked up with the wet powdery matter. To prevent this, it may be convenient to place above the cloth a piece of fine Fly's wirework; but as metallic matters are apt to be corroded, the method used by Dr Black is the most eligible. The Doctor first drops a rugged stone into the tube of the funnel, in a certain place of which it forms itself a firm bed, while the inequalities on its surface afford interstices of sufficient size for the passage of the filtering liquor. On the upper surface of this stone he puts a thin layer of lint or clean tow; immediately above this, but not in contact with it, he drops a stone similar to the former, and of a size proportioned to the swell in the upper part of the tube of the funnel. The interstices between this second stone and the funnel are filled up with stones of a less dimension, and the gradation uniformly continued till pretty small sand is employed. Finally, this is covered with a layer of coarser sand and small stones to sustain the weight of the matter, and to prevent its being invadeced in the minute interstices of the fine sand. The throat of the funnel being thus built up, the flaky fabric is to be freed of clay and other adhering impurities, by making clean water pass through it till the water comes clear and transparent from the extremity of the funnel. It is obvious, that in this contrivance, the author has, as usual, copied nature in the means she employs to depurate watery matters in the bowels of the earth; and it might be usefully applied for the filtration of various other fluids.

It is a very necessary caution to pour the water gently into the funnel; for if it be thrown in a forcible stream, a quantity of the powdery matter will be washed down, and render all our previous labour useless. That part of the ley holding the greatest quantity of salt in solution will no doubt be heavieft, and will consequently sink lowest in the vessel: the agitation of the ley is therefore necessary, in order to procure a solution of uniform strength through all its parts. If the salt has been previously freed of oily and other inflammable matters, this ley will be colourless and void of smell. If the quicklime has been so effectually deprived of its own fixed air, as to be able to absorb the whole of that in the alkali, the ley will make no effervescence with acids, being now deprived of fixed air, to the discharge of which by acids this appearance is to be ascribed in the mild or aerated alkalis.

The caustic ley is therefore to be considered as a solution of pure alkali in water. See the article Fixed Air.

It may be proper to observe, for the sake of understanding the whole of the theory of the above process, that while the alkali has become caustic, from being deprived of fixed air by the quicklime, the lime has in its turn become mild and insoluble in water from having received the fixed air of the alkali.

The caustic ley, under various pompous names, has been much used as a lithontriptic; but its fame is now beginning to decline. In acidities in the stomach, attended with much flatulence and laxity, the caustic ley is better adapted than mild alkalis; as in its union with the acid matter it does not separate air. When covered with mucilaginous matters, it may be safely taken into the stomach: and by stimulating, it coincides with the other intentions of cure; by some dyspeptic patients it has been employed with advantage.

**Pure kali. L.**

Take of water of pure kali, one gallon. Evaporate it to dryness; after which let the salt melt on the fire, and pour it out.

**The strongest common caustic. E.**

Take of caustic ley, what quantity you please. Evaporate it in a very clean iron vessel on a gentle fire till, till, on the ebullition ceasing, the saline matter gently flows like oil, which happens before the vessel becomes red. Pour out the caustic thus liquefied on a smooth iron plate; let it be divided into small pieces before it hardens, which are to be kept in well-tuft phials.

These preparations may be considered as differing in no essential particular. But the directions given by the Edinburgh college are the most precise and distinct.

The effect of the above processes is simply to discharge the water of the solution, whereby the causticity of the alkali is more concentrated in any given quantity. These preparations are strong and sudden caustics. The caustic prepared in this way has an inconvenience of being apt to liquefy too much on the part to which it is applied, so that it is not easily confined within the limits in which it is intended to operate; and indeed the suddenness of its action depends on this disposition to liquefy.

**Lime with pure kali. L.**

Take of quicklime, five pounds and four ounces; water of pure kali, 16 pounds by weight. Boil away the water of pure kali to a fourth part; then sprinkle in the lime, reduced to powder by the affusion of water. Keep it in a vessel close stoppered.

**The milder common caustic. E.**

Take of caustic ley, what quantity you please. Evaporate in an iron vessel till one-third remains; then mix with it as much new-flaked quicklime as will bring it to the consistence of pretty solid pap, which is to be kept in a vessel closely stoppered.

These preparations do not essentially differ from each other, while the chief difference between the present formula and that which stood in the last edition of the London pharmacopoeia is in the name. It was then styled the strongest common caustic.

Here the addition of lime in substance renders the preparation less apt to liquefy than the foregoing, and consequently it is more easily confinable within the intended limits, but proportionally slower in its operation. The design of keeping or of flaking the lime is, that its acrimony may be somewhat abated.

Exposed long to the air, these preparations gradually refuse their power of effervescence, and lose proportionally the additional activity which the quicklime had produced in them.

**Prepared natron. L.**

Take of barilla, powdered, two pounds; distilled water, one gallon. Boil the barilla in four pints of water for half an hour, and strain. Boil that part which remains after straining with the rest of the water, and strain. Evaporate the mixed liquors to two pints, and set them by for eight days; strain this liquor again; and, after due boiling, set it aside to crystallize. Dissolve the crystals in distilled water; strain the solution, boil, and set it aside to crystallize.

The name of natron, here used by the London college for the fixed fossil alkali, has, as well as their name for the vegetable alkali, been objected to. And though they are here supported by the authority of the ancients, yet perhaps they would have done better in following the best modern chemists by employing the term **salt of soda**. This article differs in name only from the following.

**Fixed fossil alkaline salt purified. E.**

Take of ashes of Spanish kali, commonly called soda or barilla, as much as you please. Bruise them; then boil in water till all the salt be dissolved. Strain this through paper, and evaporate in an iron vessel, so that after the liquor has cooled the salt may concret into crystals.

By the above processes, the fossil alkali is obtained sufficiently pure, being much more disposed to crystallize than the vegetable alkali; the admixture of this last, objected to by Dr Lewis, is hereby in a great measure prevented.

It is with great propriety, that in this, as well as many other processes, the London college direct the use of distilled water, as being free from every impregnation.

The natron, or fossil alkali, is found lying on the ground in the island of Teneriff, and some other countries. The native productions of this salt seem to have been better known to the ancients than to late naturalists; and it is, with good reason, supposed to be the nitre of the Bible. How far the native natron may supercede artificial means to procure it from mixed bodies, we have not been able to learn with certainty.

The fossil alkali is not only a constituent of different neutrals, but is also sometimes employed as a medicine by itself. And in its purified state it has been by some reckoned useful in affections of the scrofulous kind. See **Natrum**.

**Prepared ammonia. L.**

Take of sal ammoniac, powdered, one pound; prepared chalk, two pounds. Mix and sublime.

**Water of ammonia. L.**

Take of sal ammoniac, one pound; pot-ash, one pound and a half; water, four pints. Draw off two pints, by distillation, with a slow fire.

**Volatile alkali from sal ammoniac**, commonly called volatile sal ammoniac.

Take of sal ammoniac, one pound; chalk, very pure and dry, two pounds; mix them well, and sublime from a retort into a refrigerated receiver.

**Spirit of sal ammoniac. E.**

Take sal ammoniac, purified vegetable fixed alkali, of each fifteen ounces; water, two pounds. Having mixed the salts, and put them into a glass retort, pour in the water; then distil to dryness with a sand-bath, gradually raising the heat.

These articles, which in the last edition of the London pharmacopoeia were styled the volatile salt and spirit of sal ammoniac, were then directed to be prepared in the same manner.

Sal ammoniac is a neutral salt, composed of volatile alkali and marine acid. In these processes the acid is absorbed by the fixed alkali or chalk; and the volatile alkali is of course set at liberty.

The volatile alkali is, however, in its mild state, being being combined with the fixed air, or discharged from the fixed alkali or chalk on their uniting with the muriatic acid.

The fixed alkali begins to act on the sal ammoniac, and extricates a pungent urinous odour as soon as they are mixed. Hence it is most convenient not to mix them till put into the distilling vessel. The two salts may be dissolved separately in water, the solutions poured into a retort, and a receiver immediately fitted on. An equal weight of the fixed salt is fully, perhaps more than sufficient to extricate all the volatile.

Chalk does not begin to act on the sal ammoniac till a considerable heat is applied. Hence they may be without inconvenience, and indeed ought to be thoroughly mixed together before they are put into the retort. The surface of the mixture may be covered with a little more powdered chalk, to prevent such particles of the sal ammoniac as may happen to lie uppermost from subliming unchanged. Though the fire must here be much greater than when fixed alkaline salt is used, it must not be strong, nor suddenly raised; for if it be, a part of the chalk (though of itself not capable of being elevated by any degree of heat) will be carried up along with the volatile salt. M. du Hamel experienced the justness of this observation. He relates, in the Memoirs of the French Academy of Sciences for the year 1735, that he frequently found his volatile salt, when a very strong fire was used in the sublimation, amount to more, sometimes by a half, than the weight of the crude sal ammoniac employed; and although not three-fourths of this concrete are pure volatile salt, yet the fixed earthy matter, when once volatilized by the alkali, arose along with it again on the gentlest sublimation, dissolved with it in water, and exhaled with it in the air.

When all the salt has sublimed, and the receiver grown cool, it may be taken off, and luted to another retort charged with fresh materials. This process may be repeated till the recipient appears lined with volatile salt to a considerable thickness: the well must then be broken in order to get out the salt.

The volatile salt and spirit of sal ammoniac are the purest of all the medicines of this kind. They are somewhat more acrimonious than those produced directly from animal substances, which always contain a portion of the oil of the subject, and receive from thence some degree of a saponaceous quality. These salts may be reduced to the same degree of purity by combining them with acids into ammonical salts, and afterwards recovering the volatile alkali from these compounds by the processes above directed.

The matter which remains in the retort after the distillation of the spirit, and sublimation of the volatile sal ammoniac, is found to consist of marine acid united with the fixed alkali or chalk employed. When fixed alkaline salt has been used as the intermediate, the residuum, or caput mortuum as it is called, yields, on solution and crystallization, a salt exactly similar to the spirit of sea-salt coagulated afterwards described; and hence we may judge of the extraordinary virtues formerly attributed to this salt under the names of sal antilyfericum, antilypochondriacum, febrifugum, diglycicum Sylvii, &c.

The caput mortuum of the volatile salt, where chalk is employed as an intermediate, exposed to a moist air, runs into a pungent liquor, which proves nearly the same with a solution of chalk made directly in the marine acid. It is called by some oleum cretæ, oil of chalk. If calcined shells, or other animal limes, be mingled with sal ammoniac, a mass will be obtained, which likewise deliquesces in the air, and forms a liquor of the same kind.

Water of pure ammonia. L.

Take of sal ammoniac, one pound; quicklime, two pounds; water, one gallon. Add to the lime two pints of the water. Let them stand together an hour; then add the sal ammoniac and the other six pints of water boiling, and immediately cover the vessel. Pour out the liquor when cold, and distil off with a slow fire one pint.

Cautic volatile alkali, commonly called spirit of sal ammoniac with quicklime. E.

Take of quicklime, fresh burnt, two pounds; water, one pound. Having put the water into an iron or stone-ware vessel, add the quicklime previously beat; cover the vessel for 24 hours; when the lime has fallen into a fine powder, put it into the retort; then add 16 ounces of sal ammoniac, diluted with four times its weight of water; and, shutting the mouth of the retort, mix them together by agitation. Lastly, distil into a refrigerated receiver, with a very gentle heat, so that the operator can easily bear the heat of the retort applied to his hands. Twenty ounces of liquor are to be drawn off. In this distillation the vessels are to be so fitted as thoroughly to exclude the vapours, which are very penetrating. After the distillation, however, they are to be opened, and the alkali poured out before the retort hath altogether cooled.

The theory of this process is precisely the same with that directed for the preparation of caustic ley. The effect of the quicklime on the sal ammoniac is very different from that of the chalk and fixed alkali in the foregoing process. Immediately on mixture a very penetrating vapour exhales; and in distillation the whole of the volatile salt arises in a liquid form, no part of it appearing in a concrete state, how gently soever the liquor be re-distilled. This spirit is far more pungent than the other both in smell and taste; and, like fixed alkalis rendered caustic by the same intermediate, it raises no effervescence on mixture with acids. The whole of the phenomena are to be ascribed to the absorption of fixed air from the alkali by means of the quicklime; and from being thus deprived of the aerial acid the volatile alkali is brought to a caustic state.

This spirit is held to be too acrimonious for internal use, and has therefore been chiefly employed for smelling to in faintings, &c., though, when properly diluted, it may be given inwardly with safety. It is a powerful menstruum for some vegetable substances, as Peruvian bark, from which the other spirits extract little. It is also most convenient for the purpose of rendering oils miscible with water, as in the preparation of what is called in extemporaneous practice the oily mixture.

Some have mixed a quantity of this with the officinal spirits both of sal ammoniac and of hartshorn; which thus become more pungent, so as to bear an addition... addition of a considerable quantity of water, without any danger of the discovery from the taste or smell. This abuse would be prevented, if what has been formerly laid down as a mark of the strength of these spirits (some of the volatile salt remaining undissolved in them) were attended to. It may be detected by adding to a little of the suspected spirit about one-fourth its quantity or more of rectified spirit of wine; which, if the volatile spirit be genuine, will precipitate a part of its volatile salt, but occasions no visible separation or change in the caustic spirit, or in those which are sophicated with it.

Others have substituted for the spirit of sal ammoniac a solution of crude sal ammoniac and fixed alkaline salt mixed together. This mixture deposits a saline matter on the addition of spirit of wine, like the genuine spirit; from which, however, it may be distinguished, by the salt which is thus separated not being a volatile alkali, but a fixed neutral salt. The abuse may be more readily detected by a drop or two of solution of silver in aquafortis, which will produce no change in the appearance of the true spirit, but will render the counterfeit turbid and milky.

The volatile liquor, salt, and oil, of hartshorn. I.

Take of hartshorn, ten pounds. Distil with a fire gradually increased. A volatile liquor, salt, and oil, will ascend. The oil and salt being separated, distil the liquor three times. To the salt add an equal weight of prepared chalk, and sublime thrice, or till it become white.

The same volatile liquors, salt, and oil, may be obtained from any parts (except the fat) of all kinds of animals.

The volatile alkali obtained from hartshorn, whether in a solid or fluid state, is precisely the same with that obtained from sal ammoniac. And as that process is the easiest, the Edinburgh college have entirely rejected the present. While, however, the names of spirit and salt of hartshorn are still in daily use, ammonia, or the volatile alkali, is still prepared from bones and other animal substances by several very extensive traders.

The wholesale dealers have very large pots for the distillation of hartshorn, with earthen heads almost like those of the common still; for receivers, they use a couple of oil jars, the mouths of which are luted together; the pipe that comes from the head enters the lowermost jar through a hole made on purpose in its bottom. When a large quantity of the subject is to be distilled, it is customary to continue the operation for several days successively; only unluting the head occasionally to put in fresh materials.

When only a small quantity of spirit or salt is wanted, a common iron pot, such as is usually fixed in sand furnaces, may be employed, an iron head being fitted to it. The receiver ought to be large, and a glass, or rather tin adopter, inserted between it and the pipe of the head.

The distilling vessel being charged with pieces of the horn, a moderate fire is applied, which is slowly increased, and raised at length almost to the utmost degree. At first a watery liquor arises, the quantity of which will be smaller or greater according as the horns were more or less dry: this is succeeded by the salt and oil: the salt at first dissolves as it comes over in the phlegm, and thus forms what is called spirit. Preparations and Compositions.

When the phlegm is saturated, the remainder of the tinctures and concretes in a solid form to the sides of the recipient. If it be required to have the whole of the salt solid and undissolved, the phlegm should be removed as soon as the salt begins to arise, which may be known by the appearance of white fumes; and that this may be done the more commodiously, the receiver should be left unluted till this first part of the process be finished. The white vapours which now arise sometimes come with such vehemence as to throw off or burst the receiver. To prevent this accident, it is convenient to have a small hole in the luting, which may be occasionally stopped with a wooden peg, or opened, as the operator shall find proper. After the salt has all arisen, a thick dark-coloured oil comes over. The process is now to be discontinued; and the vessels, when grown cold, unluted.

All the liquid matters being poured out of the receiver, the salt which remains adhering to its sides is to be washed out with a little water and added to the rest. It is convenient to let the whole stand for a few hours, that the oil may the better disengage itself from the liquor, so as to be first separated by a funnel, and afterwards more perfectly by filtration through wet paper. The salt and spirits are then to be farther purified as above directed.

The spirit of hartshorn met with in the shops is extremely precarious in point of strength; the quantity of salt contained in it (on which its efficacy depends) varying according as the distillation in rectifying it is continued for a longer or shorter time. If after the volatile salt has arisen, so much of the phlegm or watery part be driven over as is just sufficient to dissolve it, the spirit will be fully saturated, and as strong as it can be made. If the process be not at this instant stopped, the phlegm, continuing to arise, must render the spirit continually weaker and weaker. The distillation therefore ought to be discontinued at this period, or rather while some of the salt still remains undissolved; the spirit will thus prove always equal, and the buyer be furnished with a certain criterion of its strength. Very few have taken any notice of the above-mentioned inconvenience of these kinds of spirits; and the remedy is first hinted at in the Pharmacopoeia Reformata. The purity of the spirit is easily determined from its clearness and grateful odour.

Volatile alkaline salts, and their solutions called spirits, agree in many respects with fixed alkaids, and their solutions or leys; as in changing the colour of blue flowers to a green; effervescing, when in their mild state, with and neutralizing acids; liquefying the animal juices; and corroding the fleshy parts, so as, when applied to the skin, and prevented from exhaling by a proper covering, to act as caustics; dissolving oils and sulphur, though less readily than the fixed alkaids, on account probably of their not being able to bear any considerable heat, by which their activity might be promoted. Their principal difference from the other alkaids seems to consist in their volatility. They exhale or emit pungent vapours in the coldest state of the atmosphere; and by their stimulating smell they prove serviceable in languors and faintings. Taken internally, they discover a greater colligating as well as stimulating power; the blood drawn from a vein, vein, after their use has been continued for some time, is said to be remarkably more fluid than before; they are likewise more disposed to operate by perspiration, and to act on the nervous system. They are particularly useful in lethargic cases; in hysterical and hypochondriacal disorders; and in the languors, headaches, inflammations of the stomach, flatulent colics, and other symptoms which attend them. They are generally found more serviceable to aged persons, and in phlegmatic habits, than in the opposite circumstances. In some fevers, particularly those of the low kind, accompanied with a cough, hoarseness, and a redundancy of phlegm, they are of great utility, raising the vis viva, and exciting a salutary diaphoresis; but in putrid fevers, scurries, and wherever the mala of blood is thin and acrimonious, their use is ambiguous. As they are more powerful than the fixed in liquefying tenacious humours, so they prove more hurtful where the fluids are already in a congealed state. In vernal intermittents, particularly those of the slow kind, they are often the most efficacious remedy. Dr Biffl observes, in his Essay on the Medical Constitution of Great Britain, that though many cases occur which will yield to no other medicine than the bark, yet he has met with many which were only suppurated from time to time by the bark, but were completely cured by alkaline spirits. He tells us, that these spirits will often carry off vernal intermittents without any previous evacuation; but that they are generally more effectual if a purge be premised; and in plethoric or inflammatory cases, or where the fever perniciously returns, venefication is necessary.

These salts are most commodiously taken in a liquid form, largely diluted; or in that of a bolus, which should be made up only as it is wanted. The dose is from a grain or two to ten or twelve. Ten drops of a well made spirit, or saturated solution, are required to contain about a grain of the salt. In intermittents, 15 or 20 drops of the spirit are given in a tea-cupful of cold spring water, and repeated five or six times in each intermission.

The volatile salts and spirits prepared from different animal substances, have been supposed capable of producing different effects on the human body, and to receive specific virtues from the subject. The salt of vipers has been esteemed particularly serviceable in disorders occasioned by the bite of that animal; and a salt drawn from the human skull, in diseases of the head. But modern practice acknowledges no such different effects from these preparations; and chemical experiments have shown their identity. There is indeed, when not sufficiently purified, a very perceptible difference in the smell, taste, degree of pungency, and volatility of these salts; and in this state their medicinal virtues vary considerably enough to deserve notice; but this difference they have in common, according as they are more or less loaded with oil, not as they are produced from this or that animal substance. As first distilled, they may be looked on as a kind of volatile soap, in which the oil is the prevailing principle; in this state they have much less of the proper alkaline acrimony and pungency than when they have undergone repeated distillations, and such other operations as disengage the oil from the salt; for by these means they lose their saponaceous quality, and acquiring greater degrees of acrimony, become medicines of a different class. These preparations therefore do not differ near so much from each other, as they do from themselves in different states of purity.

To which may be added, that when we consider them as loaded with oil, the virtues of a distilled animal oil itself are likewise to be brought into the account.

These oils, as first distilled, are highly fetid and offensive, of an extremely heating quality, and of such activity, that, according to Hoffman's account, half a drop dissolved in a dram of spirit of wine is sufficient to raise a copious sweat. By repeated rectifications, they lose their offensiveness, and at the same time become mild in their medicinal operation. The rectified oils may be given to the quantity of twenty or thirty drops, and are said to be anodyne and antipathetic, to procure a calm sleep and gentle sweat, without heating or agitating the body, as has been observed in treating of the animal oil. It is obvious, therefore, that the salts and spirits must differ, not only according to the quantity of oil they contain, but according to the quality of the oil itself in its different states.

The volatile salt and spirits, as first distilled, are of a brown colour, and a very offensive smell: by repeated rectification, as directed in the processes above set down, they lose great part of the oil on which these qualities depend; the salt becomes white, the spirit limpid as water, and of a grateful odour; and this is the mark of sufficient rectification.

It has been objected to the repeated rectification of these preparations, that, by separating the oil, it renders them similar to the pure salt and spirit of sal ammoniac, which are procurable at an easier rate. But the intention is not to purify them wholly from the oil, but to separate the groser part, and to sublimate the rest, so as to bring it towards the same state as when the oil is rectified by itself. The rectification of spirit of hartshorn has been repeated twenty times successively, and found still to participate of oil, but of an oil very different from what it was in the first distillation.

The rectified oils, in long-keeping, become again fetid. The salts and spirits also, however carefully rectified, suffer in length of time the same change; resuming their original brown colour and ill smell; a proof that the rectification is far from having divested them of oil. Any intentions, however, which they are thus capable of answering, may be as effectually accomplished by a mixture of the volatile alkali with the animal oil, in its rectified state, to any extent that may be thought necessary.

Vitriolated salt. L.

Take of the salt which remains after the distillation of the nitrous acid, two pounds. Distilled water, two gallons. Burn out the superfluous acid with a strong fire in an open vessel; then boil it a little while in the water; strain and set the liquor aside to crystallize.

The salt thus formed is the same with the vitriolated tartar of the last edition of the London pharmacopoeia; but it is now prepared in a cheaper and easier manner, at least for those who distil the nitrous acid. In both ways a neutral is formed, consisting of the fixed vege- table alkali, united to the vitriolic acid. But a similar compound may also be obtained by the following process of the Edinburgh pharmacopoeia.

**Vitriolated fixed vegetable alkali**, commonly called vitriolated tartar. E.

Take of vitriolic acid, diluted with six times its weight of water, as much as you please. Put it into a capacious glass vessel, and gradually drop into it, of purified fixed vegetable alkali, diluted with six times its weight of water, as much as is sufficient thoroughly to neutralize the acid. The effervescence being finished, strain the liquor through paper; and after proper evaporation, let it aside to crystallize.

The operator ought to take care that the vapour separated during the effervescence shall not be applied to his nostrils; as fixed air, when applied to the olfactory nerves, is highly deleterious to life.

This is an elegant and one of the least troublesome ways of preparing this salt. The Edinburgh college, in their former editions, ordered the acid liquor to be dropped into the alkaline: by the converse procedure now received, it is obviously more easy to secure against a redundancy of acidity; and for the greater certainty in this point, it may be expedient, as in the foregoing process, to drop in a little more of the alkaline ley than the cessation of the effervescence seems to require.

In a former edition of the same pharmacopoeia, the acid was directed to be diluted only with its equal weight of water, and the alkali with that quantity of water which it is capable of imbibing from the atmosphere. By that imperfection there was not water enough to keep the vitriolated tartar dissolved; on which account, as fast as the alkali was neutralized by the acid, a great part fell to the bottom in a powdery form. In order to obtain perfect and well formed crystals, the liquor should not be set in the cold, but continued in moderate heat, such as the hand can scarcely bear, that the water may slowly evaporate.

It is remarkable, that although the vitriolic acid and fixed alkaline salt do each readily unite with water, and strongly attract moisture, even from the air, yet the neutral resulting from the combination of these two, vitriolated tartar, is one of the salts most difficult of solution, very little of it being taken up by cold water.

Vitriolated tartar, in small doses, as a scuple or half a dram, is an useful aperient; in large ones, as four or five drams, a mild cathartic, which does not pass off so hastily as the bitter cathartic sal or salt of Glauber, and seems to extend its action further. The wholesale dealers in medicines have commonly substituted for it an article otherwise almost useless in their shops, the residuum of Glauber's spirit of nitre. This may be looked on as a venial fraud, if the spirit has been prepared as formerly directed, and the residuum dissolved and crystallized: but it is a very dangerous one if the vitriolic acid has been used in an over proportion, and the caput mortuum employed without crystallization; the salt in this case, instead of a mild neutral one, of a moderately bitter taste, proving highly acid. The purchaser ought therefore to insist on the salt being in a crystalline form. The crystals when perfect are oblong, with six flat sides, and terminated at each end by a fixed pyramid; some appear composed of two pyramids joined together by the bases; and many, in the most perfect crystallizations we have seen, are very irregular. They decrepitate in the fire, somewhat like those of sea-salt, for which they have sometimes been mistaken.

**Salt of many virtues.** E.

Take nitre in powder, flowers of sulphur, of each equal parts. Mix them well together, and inject the mixture by little and little at a time into a red-hot crucible: the deflagration being over, let the salt cool, after which it is to be put up in a glass vessel well shut. The salt may be purified by dissolving it in warm water, filtering the solution, and exhausting it to dryness, or by crystallization.

This is another method of uniting the vitriolic acid with the common vegetable fixed alkali. Both the nitre and the sulphur are decomposed in the operation: the acid of the nitre, and the inflammable principle of the sulphur, detonate together, and are dissipated; while the acid of the sulphur (which, as we have already seen, is no other than the vitriolic acid) remains combined with the alkaline basis of the nitre. The shops accordingly have substituted the foregoing preparation for the sal pochyreft.

**Vitriolated natron.** L.

Take of the salt which remains after the distillation of the muriatic acid, two pounds; distilled water, two pints and an half. Burn out the superfluous acid with a strong fire in an open vessel; then boil it for a little in the water: strain the solution, and let it by to crystallize.

**Vitriolated soda**, commonly called cathartic salt of Glauber. E.

Dissolve in warm water the mass which remains after the distillation of spirit of sea-salt: filter the solution, and crystallize the salt.

The directions given for the preparation of this salt, long known by the name of sal mirabile Glauberis, are nearly the same in the pharmacopoeias of both colleges; but those of the London college are to be preferred, as being most accurate and explicit.

In a former edition of the Edinburgh pharmacopoeia, it was ordered, that if the crystals (obtained as above) proved too sharp, they should be again dissolved in water, and the filtered liquor evaporated to such a pitch only as may dispose the salt to crystallize. But there is no great danger of the crystals proving too sharp, even when the spirit of salt is made with the largest proportion of oil of vitriol directed under that process. The liquor which remains after the crystallization is indeed very acid; and with regard to this preparation, it is convenient it should be so; for otherwise the crystals will be very small, and likewise in a small quantity. Where a sufficient proportion of oil of vitriol has not been employed in the distillation of the spirit, it is necessary to add some to the liquor, in order to promote the crystallization of the salt.

The title of cathartic salt, which this salt has often had, expresses its medical virtues. Taken from half an ounce to an ounce, or more, it proves a mild and useful purgative; and in smaller doses, largely diluted, a serviceable aperient and diuretic. The shops frequently substitute for it the bitter cathartic salt, which is nearly of the same quality, but somewhat more unpleasant, and, as is said, less mild in operation. They are very easily distinguishable from each other, by the effect of alkaline salts upon solutions of them. The solutions of Glauber's salt suffer no visible change from this addition, its own basis being a true fixed alkali: but the solution of the bitter cathartic salt grows instantly white and turbid; its basis, which is an earth, being extricated copiously by the alkaline salt.

**Purified nitre. L.**

Take of nitre two pounds; distilled water, four pints. Boil the nitre in the water till it be dissolved; strain the solution, and let it aside to crystallize.

Common nitre contains usually a considerable portion of sea-salt, which in this process is separated, the sea-salt remaining dissolved after the greatest part of the nitre has crystallized. The crystals which shoot after the first evaporation are large, regular, and pure: but when the remaining liquor is further evaporated, and this repeated a second or third time, the crystals prove at length small, imperfect, and tipped with little cubical crystals of sea-salt.

When rough nitre, in the state wherein it is first extracted from the earths impregnated with it, is treated in this manner, there remains at last a liquor, called mother-ley, which will no longer afford any crystals. This appears to participate of the nitrous and marine acids, and to contain an earthy matter dissolved by those acids. On adding alkaline lixivium, the earth is precipitated; and when thoroughly washed with water, proves insipid. If the liquor be evaporated to dryness, a bitterish saline matter is left; which being strongly calcined in a crucible, parts with the acids, and becomes, as in the other case, insipid.

This earth has been celebrated as an excellent purgative, in the dose of a dram or two; and, in smaller doses, as an alterant in hypochondriacal and other disorders. This medicine was for some time kept a great secret, under the name of magnesia alba, nitrous panacea, Count Palma's powder, il polvere albo Romano, poudre de Sentinelli, &c., till Lancisi made it public in his notes on the Metallothea Vaticana. It has been supposed, that this earth is no other than a portion of the lime commonly added in the elixir of nitre at the European nitre-works; but though the specimens of magnesia examined by Neumann, and some of that which has lately been brought hither from abroad, gave plain marks of a calcareous nature; yet the true magnesia must be an earth of a different kind, calcareous earths being rather astringent than purgative. The earthy basis of the bitter cathartic salt is found to have the properties ascribed to the true magnesia of nitre, and appears to be the very same species of earth: from that salt therefore this medicine is now prepared, as will be seen hereafter. The magnesia alba differs from calcareous earths, in having a less powerful attraction for fixed air, and in not becoming caustic by calcination.

**Acetated kali. L.**

Take of kali one pound; boil it with a slow fire in four or five times its quantity of distilled vinegar; the effervescence ceasing, let there be added at different times more distilled vinegar, until the last vinegar being nearly evaporated, the addition of fresh will excite no effervescence, which will happen when about twenty pounds of distilled vinegar are consumed; afterwards let it be dried slowly. An impure salt will be left, which melt for a little while with a slow fire; then let it be dissolved in water, and filtered through paper. If the fusion has been rightly performed, the strained liquor will be colourless; if otherwise, of a brown colour. Lastly, evaporate this liquor with a slow fire, in a very shallow glass vessel; frequently stirring the mass, that the salt may be more completely dried, which should be kept in a vessel closely stopped. The salt ought to be very white, and dissolve wholly both in water and spirit of wine, without leaving any feces. If the salt, although white, should deposit any feces in spirit of wine, that solution in the spirit should be filtered through paper, and the salt again dried.

**Acetated fixed vegetable alkali, commonly called regenerated tartar. E.**

Take of salt of tartar one pound; boil it with a very gentle heat in four or five times its quantity of distilled vinegar; add more distilled vinegar at different times, till on the watery part of the former quantity being nearly dissipated by evaporation, the new addition of vinegar ceases to raise any effervescence. This happens when about twenty pounds by weight of distilled vinegar has been consumed. The impure salt remaining after the exsiccation, is to be liquefied with a gentle heat for a short time, and it is proper that it should only be for a short time; then dissolve it in water, and strain through paper. If the liquefaction has been properly performed, the strained liquor will be limpid; but if otherwise, of a brown colour. Evaporate this liquor with a very gentle heat in a shallow glass vessel, occasionally stirring the salt as it becomes dry, that its moisture may sooner be dissipated. Then put it up into a vessel very closely stopped, to prevent it from liquefying in the air.

This salt had formerly the name of diuretic salt in the London pharmacopoeia; but that which they now employ, or perhaps in preference to it, the name of potassa acetata, gives a clearer idea of its nature.

The purification of this salt is not a little troublesome. The operator must be particularly careful, in melting it, not to use a great heat, or to keep it long liquefied; a little should be occasionally taken out, and put into water; and as soon as it begins to part freely with its black colour, the whole is to be removed from the fire. In the last drying, the heat must not be so great as to melt it; otherwise it will not prove totally insoluble. If the solution in spirit of wine be effevedicated, and the remaining salt liquefied with a very gentle fire, it gains the leafy appearance which has procured it the name terra foliata. In the fourth volume of the Memoirs of the correspondents of the French Academy, lately published, Mr. Cadet has given a method of making the salt white at the first evaporation, without the trouble of any farther purification. He observes, that the brown colour depends on the oily matter of the vinegar being burnt by the heat commonly employed in the evaporation; and his improvement consists in diminishing the heat at the time that this burning is liable to happen. The process he recommends is as follows:

Dissolve a pound of salt of tartar in a sufficient quantity of cold water; filter the solution, and add by degrees as much distilled vinegar as will saturate it, or a little more. Set the liquor to evaporate in a stone-ware vessel in a gentle heat, not so strong as to make it boil. When a pellicle appears on the surface, the rest of the process must be finished in a water-bath. The liquor acquires by degrees an oily consistence, and a pretty deep brown colour; but the pellicle or scum on the top looks whitish, and when taken off and cooled, appears a congeries of little brilliant silver-like plates. The matter is to be kept continually stirring, till it be wholly changed into this white flaky matter; the complete drying of which is most conveniently effected in a warm oven.

We shall not take upon us to determine whether the pure or impure salt is preferable as a medicine; observing only, that the latter is more of a saponaceous nature, the former more acid, though somewhat more agreeable to the stomach. Mr. Cadet reckons the salt prepared in his method superior both to the brown and white sorts made in the common way, as possessing both the oily quality of the one and the agreeableness of the other, and as being always uniform or of the same power; whereas the others are liable to vary considerably, according to the degree of heat employed in the evaporation. They are all medicines of great efficacy, and may be so dosed and managed as to prove either mildly cathartic, or powerfully diuretic: few of the saline deobstruents come up to them in virtue. The dose is from half a scruple to a dram or two. A bare mixture, however, of alkaline salt and vinegar, without effervescence, is not perhaps much inferior as a medicine to the more elaborate salt. Two drams of the alkali, saturated with vinegar, have been known to occasion ten or twelve stools in hydroptic cases, and a plentiful discharge of urine, without any inconvenience.

Water of acetated ammonia. L.

Take of ammonia, by weight, two ounces; distilled vinegar, four pints; or as much as is sufficient to saturate the ammonia. Mix.

Spirit of Mindererus. E.

Take any quantity of the volatile alkaline salt of sal ammoniac, and gradually pour upon it distilled vinegar till the effervescence ceases; occasionally stirring the mixture to promote the action of the vinegar on the salt.

Though this article has long been known by the name of Spiritus Mindereri, so called from the inventor; yet that employed by the London college is undoubtedly preferable, as giving a proper idea of its constituent parts.

This is an excellent aperient saline liquor. Taken warm in bed, it proves commonly a powerful diaphoretic or sudorific; and as it operates without heat, it has place in febrile and inflammatory disorders, where medicines of the warm kind, if they fail of procuring sweat, aggravate the distemper. Its action may likewise be determined to the kidneys, by walking about in a cool air. The common dose is half an ounce, either by itself, or along with other medicines adapted to the intention. Its strength is not a little precarious, depending much on that of the vinegar; an inconvenience which cannot easily be obviated, for the saline matter is not reducible to the form of a concrete salt.

Tartarized kali. L.

Take of kali one pound; crystals of tartar, three pounds; distilled water, boiling, one gallon. To the salt, dissolved in water, throw in gradually the crystals of tartar, powdered: filter the liquor, when cold, through paper: and, after due evaporation, let it apart to crystallize.

Tartarized vegetable fixed alkali, commonly called soluble tartar. E.

Take of purified fixed vegetable alkaline salt one pound; water, 15 pounds. To the salt dissolved in the boiling water gradually add crystals of tartar in fine powder, as long as the addition thereof raises any effervescence, which almost ceases before three times the weight of the alkaline salt hath been injected; then strain the cooled liquor through paper, and after due evaporation let it aside to crystallize.

Common white tartar is perhaps preferable for this operation to the crystals usually met with. Its impurities can here be no objection; since it will be sufficiently depurated by the subsequent filtration.

The preparation of this medicine by either of the above methods is very easy; though some chemists have rendered it sufficiently troublesome, by a nicety which is not at all wanted. They insist upon hitting the very exact point of saturation between the alkaline salt and the acid of the tartar; and caution the operator to be extremely careful, when he comes near this mark, lest by imprudently adding too large a portion of either, he render the salt too acid or too alkaline. If the liquor be suffered to cool a little before it be committed to the filter, and then properly exhaled and crystallized, no error of this kind can happen, though the saturation should not be very exactly hit: for since crystals of tartar are very difficultly soluble even in boiling water, and when dissolved therein concrete again upon the liquor's growing cold, if any more of them has been employed than is taken up by the alkali, this superfluous quantity will be left upon the filter; and, on the other hand, when too much of the alkali has been used, it will remain uncryallized. The crystallization of this salt indeed cannot be effected without a good deal of trouble: it is therefore most convenient to let the acid salt prevail at first; to separate the superfluous quantity, by suffering the liquor to cool a little before filtration; and then proceed to the total evaporation of the aqueous fluid, which will leave behind it the neutral salt required. The most proper vessel for this purpose is a stone-ware one; iron discolours the salt. Soluble tartar, in doses of a scruple, half a dram, or a dram, is a mild cooling aperient; two or three drams commonly loosen the belly; and an ounce proves pretty strongly purgative. It has been particularly recommended as a purgative for maniacal and melancholic patients. Malouin says, it is equal in purgative virtue to the cathartic salt of Glauber. It is an useful addition to the purgatives of the resinous kind, as it promotes their operation, and at the same time tends to correct their gripping quality. But it must never be given in conjunction with any acid; for all acids decompose it, absorbing its alkaline salt, and precipitating the tartar. On this account it is improper to join it to tamarinds, or such like acid fruits; which is too often done in the extemporaneous practice of those physicians who are fond of mixing different cathartics together.

Tartarized natron. L.

Take of natron, 20 ounces; crystals of tartar, powdered, 2 pounds; distilled water, boiling, 10 pints. Dissolve the natron in the water, and gradually add the crystals of tartar; filter the liquor through paper; evaporate, and set it aside to crystallize.

Tartarized soda, commonly called Rochel salt. E.

The Rochel salt may be prepared from purified fossil alkaline salt and crystals of tartar, in the same manner as directed for the soluble tartar.

This is a species of soluble tartar, made with the salt of kali or soda, which is the same with the mineral alkali, or basis of sea-salt. It crystallizes far more easily than the preceding preparation, and does not, like it, grow moist in the air. It is also considerably less purgative, but is equally decomposed by acids. It appears to be a very elegant salt, and begins now to come into esteem in this country, as it has long been in France.

Purification of alum. L.

Take of alum, one pound; chalk, one dram by weight; distilled water, one pint. Boil them a little, strain, and set the liquor aside to crystallize.

We have already offered some observations on alum (see Alum); and in general we may say that it comes from the alum works in England in a state of such purity as to be fit for every purpose in medicine; accordingly we do not observe that the purification of alum has a place in any other pharmacopeias; but by the present process it will be freed, not only from different impurities, but also from superabundant acid.

Burnt alum. L. E.

Take of alum, half a pound. Burn it in an earthen vessel so long as it bubbles.

This, with strict propriety, ought rather perhaps to be called dried alum than burnt alum; for the only effect of the burning here directed is to expel the water. In this state it is so acid as to be frequently employed as an astringent; and it is with this intention chiefly that it has a place in our pharmacopeias; but it has sometimes also been taken internally, particularly in cases of cholera.

Salt or sugar of milk. Succ.

Take of the whey of milk, prepared by runnet, any quantity; let it be boiled over a moderate fire to prepare the consistence of a syrup; then put it in a cold place, that crystals may be formed. Let the fluid which remains be again managed in the same manner, and let the crystals formed be washed with cold water.

It has been by some imagined, that the superiority of one milk over another depends on its containing a larger proportion of this saline or saccharine part; and particularly, that upon this the reputed virtues of its milk depend. Hence this preparation has been greatly celebrated in disorders of the breast, but it is far from answering what has been expected from it. It has little sweetness, and is difficult of solution in water. A saline substance, much better deserving the name of sugar, may be obtained by evaporating new milk, particularly that of the ass, to dryness, digesting the dry matter in water till the water has extracted its soluble parts, and then inspissating the filtered liquor. This preparation is of great sweetness, though neither white nor crystalline; nor is it perhaps in the pure crystallizable parts of milk that its medicinal virtues reside; and so little reliance is put on it as a medicine, that it has no place in the London or Edinburgh pharmacopeias; although it long has stood, and still stands, in the foreign ones.

Salt of sorrel. Succ.

Take any quantity of the expressed juice of the leaves of wood sorrel; let it boil gently, that the feculent matter may be separated; then strain it till it be clear, and after this boil it on a moderate fire to the consistence of a syrup. Put it into long-necked glass vessels, and place it in a cold situation that it may crystallize. Let these crystals be dissolved in water, and again formed into purer ones.

To make the sorrel yield its juice readily, it should be cut to pieces, and well bruised in a small mortar, before it be committed to the press. The magma which remains in the bag still retaining no inconsiderable quantity of saline matter, may be advantageously boiled in water, and the decoction added to the expressed juice. The whole may be afterwards depurated together, either by the method above directed, or by running the liquor several times through a linen cloth. In some cases the addition of a considerable portion of water is necessary, that the juice, thus diluted, may part the more freely with its feculencies; on the separation of which the success of the process much depends.

The evaporation should be performed either in shallow glass basins, or in such earthen ones as are of a compact close texture; such are those usually called stone-ware. The common earthen vessels are subject to have their glazing corroded, and are so extremely porous, as readily to imbibe and retain a good quantity of the liquor; metallic vessels are particularly apt to be corroded by these acid kinds of juices.

These juices are so viscid, and abound so much with heterogeneous matter, of a quite different nature from anything saline, that a pellicle, or pure saline incrustation upon the surface, is in vain expected. Boerhaave, therefore, and the more expert writers in pharmaceutical chemistry, with great judgment direct the evaporation of the superfluous moisture to be continued until until the matter has acquired the consistence of cream. If it be now suffered to stand for an hour or two in a warm place, it will, notwithstanding the former depurations, deposit a fresh sediment, from which it should be warily decanted before it be put into the vessel in which it is designed to be crystallized.

Some recommend an unglazed earthen vessel as preferable for this purpose to a glass one; the smoothness of the latter being supposed to hinder the salt from sticking thereto; while the juice easily infusing itself into the pores of the former, has a great advantage of shooting its saline spicula to the sides. Others slightly incrustate the sides and bottom of whatever vessel they employ with a certain mineral salt, which greatly deposits the juice to crystallize, to which of itself it is very adverse; but this addition is, with regard to its medical virtue, quite different from the salt here intended.

The liquor which remains after the crystallization may be depurated by a gentle colature, and after due infusion let it shoot again; when a farther produce of crystals will be obtained.

The process for obtaining this salt is very tedious; and the quantity of salt which the juices afford is extremely small; hence they are hardly ever made or expected in the shops. They may be somewhat sooner separated from the mucilage and other feculencies, by clarification with whites of eggs, and by adding very pure white clay.

In the manner above described, salts may also be obtained from other acid, astringent, and bitterish plants, which contain but a small quantity of oil.

The virtues of the essential salts have not been sufficiently determined from experience. This much, however, is certain, that they do not, as has been supposed, possess the virtues of the subjects entire, excepting only the acids and sweets. The others seem to be almost all of them nearly similar, whatever plant they were obtained from. In watery extracts of wormwood, carduus, camomile, and many other vegetables, kept for some time in a soft state, there may be observed fine saline efflorescences on the surface, which have all nearly the same taste, somewhat of the nitrous kind. They are supposed by some to be in reality no more than an impure species of volatile nitre (that is, a salt composed of the nitrous acid and volatile alkali); those which were examined by the chemists of the French academy deflagrated in the fire, and being triturated with fixed alkali, exhaled an urinous odour; plain marks of their containing those two ingredients.

**Acid salt of borax. Succ.**

Take of borax, an ounce and a half; warm spring-water, one pound. Mix them in a glass vessel, that the borax may be dissolved; then pour into it three drams of the concentrated acid of vitriol; evaporate the liquor till a pellicle appears upon it; after this let it remain at rest till the crystals be formed. Let them be washed with cold water, and kept for use.

This salt, which has long been known by the title of the *sedative salt of Homberg*, is not unfrequently formed by sublimation; but the process by crystallization here directed is less troublesome, though the salt proves generally less white, and is apt likewise to retain a part of Glauber's salt, especially if the evaporation be long protracted.

The salt of borax to the taste appears to be a neutral; but when it is examined by alkalis, it shows the properties of an acid, effervescing, uniting, and crystallizing with them, and it destroys their alkaline quality. It dissolves both in water and spirit of wine, although not very readily in either.

The virtues attributed to it may in some degree be inferred from the name of *sedative*, by which it was long distinguished. It has been supposed to be a mild anodyne, to diminish febrile heat, to prevent or remove delirium, and to allay, at least for some time, spasmodical affections, particularly those which are the attendants of hypochondria and hysteria. It may be given in doses from two to twenty grains.

**Purified sal ammoniac. Suec.**

Dissolve sal ammoniac in spring-water; strain the liquor through paper; evaporate it to dryness in a glass vessel by means of a moderate fire.

The sal ammoniac imported from the Mediterranean often contains such impurities as to render the above process necessary; but that which is prepared in Britain from foot and sea-salt, is in general brought to market in a state of very great purity. Hence this process is now altogether omitted both in the London and Edinburgh pharmacopoeias. It furnishes, however, when necessary, an easy and effectual mode of obtaining a pure ammonia muriata.

---

**CHAP. VIII. Magnesia.**

**White magnesia.**

Take of bitter purging salt, kali, each two pounds; distilled water, boiling, 20 pints. Dissolve the bitter salt and the kali separately in 10 pints of water, and filter through paper; then mix them. Boil the liquor a little while, and strain it while hot through linen, upon which will remain the white magnesia; then wash away, by repeated affusions of distilled water, the vitriolated kali. L.

Take of bitter purging salt, purified fixed vegetable alkali, equal weights. Dissolve them separately in double their quantity of warm water, and let the liquor be strained or otherwise freed from the feces; then mix them, and instantly add eight times their quantity of warm water. Let the liquor boil a little, stirring it very well at the same time; then let it rest till the heat be somewhat diminished; after which strain it through a cloth; the magnesia will remain upon the cloth, and it is to be washed with pure water till it be altogether void of saline taste. E.

The processes here directed by the London and Edinburgh colleges are nearly the same; but the former seem to have improved somewhat on the latter, both in simplifying the process, and in the employment of distilled water.

The bitter cathartic salt, or *Epsom salt*, is a combination of the vitriolic acid and magnesia. In this process, then, a double elective attraction takes place: the vitriolic acid forsakes the magnesia, and joins the mild alkali, for which it has a greater attraction; while the magnesia in its turn unites with the fixed air discharged from the mild alkali, and ready to be absorbed by any substance with which it can combine.

We have therefore two new products, viz. a vitriolated tartar, and magnesia united with fixed air. The former is dissolved in the water, and may be preferred for use; the latter, as being much less soluble, sinks to the bottom of the vessel. The intention of employing such a large quantity of water and of the boiling is, that the vitriolated tartar may be all thoroughly dissolved; this salt being so scarcely soluble in water, that without this expedient a part of it might be precipitated along with the magnesia. It might perhaps be more convenient to employ the mineral alkali; which forming a Glauber's salt with the vitriolic acid, would require less water for its suspension. By the after ablutions, however, the magnesia is sufficiently freed from any portion of vitriolated tartar which may have adhered to it.

The ablutions should be made with very pure water; for nicer purposes distilled water may be used with advantage; and soft water is in every case necessary. Hard water for this process is peculiarly inadmissible, as the principle in waters giving the property called hardness is generally owing to an imperfect nitrous felsite, whose base is capable of being disengaged by magnesia united with fixed air. For though the attraction of magnesia itself to the nitrous acid is not greater than that of calcareous earths; yet when combined with fixed air, a peculiar circumstance intervenes; whence it is deducible, that the sum of the forces tending to join the calcareous earth with the air of the magnesia, and the magnesia with the acid, is greater than the sum of the forces tending to join the calcareous earth with the acid, and the magnesia with the fixed air.

This phenomenon must therefore depend on the presence of fixed air, and its greater attraction for lime than for magnesia. On this account, if hard water be used, a quantity of calcareous earth must infallibly be deposited on the magnesia; while the nitrous acid with which it was combined in the water, will in its turn attach itself to a portion of the magnesia, forming what may be called a nitrous magnesia.

All the alkalis, and also calcareous earths, have a greater attraction for fixed air than magnesia has: Hence, if this last be precipitated from its solution in acids by caustic alkali, it is then procured free from fixed air: but for this purpose calcination is more generally employed in the manner described in the process which next follows. Magnesia is scarcely at all soluble in water: the infinitely small portion which this fluid is capable of taking up, is owing to the fixed air of the magnesia; and it has been lately discovered, that water impregnated with this acid is capable of dissolving a considerable portion: for this purpose it is necessary to employ magnesia already saturated with fixed air, as magnesia deprived of this air would quickly abstract it from the water, whereby the force of the latter would be very considerably diminished. Such a solution of magnesia might be useful for several purposes in medicine.

Magnesia is the same species of earth with that obtained from the mother-ley of nitre, which was for several years a celebrated secret in the hands of some particular persons abroad. Hoffman, who describes the preparations of the nitrous magnesia, gives it the character of an useful antacid, a safe and inoffensive laxative in doses of a dram or two, and a diaphoretic and diuretic when given in smaller doses of 15 or 20 grains. Since his time, it has had a considerable place in the practice of foreign physicians; and is now in great esteem among us, particularly in heart-burns, and for preventing or removing the many disorders which children are so frequently thrown into from a redundancy of acid humours in the first passages: it is preferred, on account of its laxative quality, to the common absorbents, which, unless gentle purgatives be occasionally given to carry them off, are apt to lodge in the body, and occasion a colliquiency very detrimental to infants.

Magnesia alba, when prepared in perfection, is a white and very subtle earth, perfectly void of smell or taste, of the class of those which dissolve in acids. It dissolves freely even in the vitriolic acid; which, in the common way of making solutions, takes up only an inconsiderable portion of other earths. Combined with this acid, it forms the bitter purging or Epsom salt, very easily soluble in water; while the common absorbents form with the same acid almost insipid concretes, very difficult of solution. Solutions of magnesia in all acids are bitter and purgative, while those of the other earths are more or less astringent and afflicting. A large dose of magnesia, if the stomach contain no acid to dissolve it, does not purge or produce any sensible effect; a moderate one, if an acid be lodged there, or if acid liquors be taken after it, procures several stools; whereas the common absorbents, in the same circumstances, instead of loosening, bind the belly. It is obvious, therefore, that magnesia is specifically different from the other earths, and that it is applicable to several useful purposes in medicine.

Magnesia was formerly made with the mother-water of nitre evaporated to dryness, or precipitated by a fixed alkali. It has gone under different names, as the white powder of the Count of Palma, powder of sentinelle, polychrest, laxative powder, &c. It seems to have got the character white, to distinguish it from the dark-coloured mineral called also magnesia or manganese; a substance possessing very different properties. We have not heard that pure native magnesia has been found in its uncombined state. A combination of it with sulphur has been discovered to cover a stratum of coal at Littyry in Lower Normandy. It has also been found in certain serpentine earths in Saxony, and in marly and alum earths.

Calcined magnesia.

Take of white magnesia, four ounces. Expose it to a strong heat for two hours; and, when cold, set it by. Keep it in a vessel closely stopped. L.

Let magnesia, put into a crucible, be continued in a red heat for two hours; then put it up in close glass vessels. E.

By this process the magnesia is freed of fixed air; which, according to Dr Black's experiments, constitutes tutes about 1/30th of its weight. A kind of opaque foggy vapour is observed to escape during the calcination, which is nothing else than a quantity of fine particles of magnesia buoyed off along with a stream of the disengaged air. About the end of the operation, the magnesia exhibits a kind of luminous or phosphorescent property; and this may be considered as a pretty exact criterion of its being deprived of air.

Calcined magnesia is equally mild as when saturated with fixed air; and this circumstance is sufficient to establish a difference between it and calcareous earths, all of which are converted by calcination into a caustic quicklime.

The calcined magnesia is used for the same general purposes as the magnesia combined with fixed air. In certain affections of the stomach, accompanied with much flatulence, the calcined magnesia is found preferable, not only as containing more of the real earth of magnesia in a given quantity, but as being also deprived of its air. It neutralizes the acid of the stomach without that extrication of air which is often a troublesome consequence in employing the aerated magnesia in these complaints. It is proper to observe, that magnesia, whether combined with or deprived of fixed air, is similar to the mild calcareous earths in promoting and increasing putrefaction. The same has even been observed with respect to the Epsom and some other salts which have this earth for their base.

**Chap. IX. Preparations of Sulphur.**

*Washed flowers of sulphur.* L.

Take of flowers of sulphur, one pound; distilled water, four pints. Boil the flowers of sulphur a little while in the distilled water; then pour off this water, and wash off the acid with cold water; lastly, dry the flowers.

In the former editions of our pharmacopoeias directions were given for the preparation of the flowers of sulphur themselves; but as a large apparatus is necessary for doing it with any advantage, it is now scarcely ever attempted by the apothecaries. When the flowers are properly prepared, no change is made on the qualities of the sulphur. Its impurities only are separated; and at the same time it is reduced to a finer powder than it can easily be brought to by any other means. But as the flowers of sulphur are generally sublimed in very capacious rooms, which contain a large quantity of air, or in vessels not perfectly close, some of those that arise at first are apt to take fire, and thus are changed into a volatile acid vapour, which mingling with the flowers that sublime afterwards, communicates to them a considerable degree of acidity. In this case the ablution here directed is for the general use of the medicine absolutely necessary; for the flowers thus tainted with acid sometimes occasion gripes, and may in other respects be productive of effects different from those of pure sulphur. There are, however, some particular combinations to which they are supposed to be better adapted when unwashed, such as their union with mercury into æthiops mineral; and accordingly for that preparation the unwashed flowers are directed by the London college.

**Sulphurated kali.** L.

Take of flowers of sulphur, one ounce; kali, five ounces. Mix the salt with the melted sulphur, by frequently stirring, until they unite into an uniform mass.

This preparation, in the former editions of our pharmacopoeias, had the name of *hepar sulphuris*, or *liver of sulphur*.

It is much more convenient to melt the sulphur first by itself, and add the salt of tartar by degrees, as here directed, than to grind them together, and afterwards endeavour to melt them, as ordered in former editions: for in this last case the mixture will not flow sufficiently thin to be properly united by stirring; and the sulphur either takes fire or sublimes in flowers, which probably has been the reason why so large a proportion of it has been commonly directed. Even in the present method a considerable part of the sulphur will be dissipated; and if it were not, the hepar would not be of its due quality: for one part of sulphur requires two of the alkaline salt to render it perfectly soluble in water, which this preparation ought to be.

The hepar sulphuris has a fetid smell and a nauseous taste. Solutions of it in water, made with sugar into a syrup, have been recommended in coughs and other disorders of the breast. Our pharmacopoeias, nevertheless, have deservedly rejected this syrup, as common practice has almost done the balsams. Solutions of the hepar in water have been also recommended in herpetic and other cutaneous affections. Some physicians have even employed this solution, in a large quantity, as a bath for the cure of psora; and in cases of tinea capitis it has often been used by way of lotion.

The hepar, digested in rectified spirit of wine, imparts a rich gold colour, a warm, somewhat aromatic taste, and a peculiar, not ungrateful smell. A tincture of this kind is kept in the shops under the name of another mineral. The hepar sulphuris has been by some strongly recommended to prevent the effects of mineral poison.

**Sulphurated oil and sulphurated petroleum.** L.

Take of flowers of sulphur, four ounces; olive oil, sixteen ounces. Boil the flowers of brimstone with the oil, in a pot slightly covered, until they be united. In the same manner is made sulphurated petroleum.

These articles are analogous to what had formerly a place in our pharmacopoeias under the titles of *balsamum sulphuris simplex*, *creatum*, et *Barbadense*. And, besides these, a place was also given to the *balsamum sulphuris animatum*, *terebinthinatum*, &c. While these articles, however, are now banished from our pharmacopoeias, even those retained are less in use than formerly.

These preparations are more conveniently and safely made in a tall glass body, with the mouth at least an inch in diameter, than in the circulatory or close vessels in which they have commonly been directed to be prepared: for when the sulphur and oil be, so to act vehemently upon each other, they not only rarify into a large volume, but likewise throw out impetuously great quantities of an elastic vapour; which, if the vessels be closed, or the orifices not sufficient to allow it it a free exit, will infallibly burst them. Hoffman relates a very remarkable history of the effects of an accident of this kind. In the vessel above recommended the process may be completed, without danger, in four or five hours, by duly managing the fire, which should be very gentle for some time, and afterwards increased so as to make the oil just bubble or boil; in which state it should be kept till all the sulphur appears to be taken up.

Essential oils, employed as menstrua for sulphur, undergo a great alteration from the degree of heat necessary for enabling them to dissolve the sulphur; and hence the balsams have not near so much of their flavour as might be expected. It should therefore seem more eligible to add a proper quantity of the essential oils to the simple balsam: these readily incorporate by a gentle warmth, if the vessel be now and then shaken. We may thus compose a balsam more elegant than those made in the manner formerly recommended, and which retains so much of the flavour of the oil as is in some measure sufficient to cover the taste of the sulphur, and render it supportable.

The balsams of sulphur have been strongly recommended in coughs, consumptions, and other disorders of the breast and lungs; but the reputation which they have had in these cases does not appear to have been built on any fair trial or experience of their virtues. They are manifestly hot, acrimonious, and irritating; and therefore should be used with the utmost caution. They have frequently been found to injure the appetite, offend the stomach and viscera, parch the body, and occasion thirst and febrile heats. The dose of the simple balsam is from ten to forty drops; those with essential oils are not given in above half these quantities. Externally, they are employed for cleansing and healing foul running ulcers. Boerhaave conjectures that their use in these cases gave occasion to the virtues ascribed to them when taken internally.

Precipitated sulphur. L.

Take of sulphurated kali, six ounces; distilled water, one pound and a half; vitriolic acid, diluted, as much as is sufficient. Boil the sulphurated kali in the distilled water until it be dissolved. Filter the liquor through paper, to which add the vitriolic acid. Wash the precipitated powder by often pouring on water till it becomes insipid.

This preparation is not so white as that of the last pharmacopoeia, which was made with quicklime; and which in some pharmacopoeias had the name of milk of sulphur.

Pure milk of sulphur is not different in quality from pure sulphur itself; to which it is preferred in unguents, &c. only on account of its colour. The whites of eggs do not proceed from the sulphur having lost any of its parts in the operation, or from any new matter superadded: for if common sulphur be ground with alkaline salts, and set to sublime, it rises of a white like colour, the whole quantity of the alkali remaining unchanged; and if the milk be melted with a gentle fire, it returns into yellow sulphur again.

It may be observed, that the name lac sulphuris, or milk of sulphur, applied among us to the precipitate, is by the French writers confined to the white liquor before the precipitate has fallen from it.

Antimony is composed of a metal, united with sulphur or common brimstone.

If powdered antimony be exposed to a gentle fire, the sulphur exhales; the metallic part remaining in form of a white calx, reducible, by proper fluxes, into a whitish brittle metal, called regulus. This is readily distinguished from the other bodies of that class, by its not being soluble in aquafortis; its proper menstruum is aqua-regia.

If aqua-regia be poured on crude antimony, the metallic part will be dissolved; and the sulphur thrown out, partly to the sides of the vessel, and partly to the surface of the liquor, in the form of a greyish yellow substance. This, separated and purified by sublimation, appears on all trials the same with pure common brimstone.

The metal freed from the sulphur naturally blended with it, and afterwards fused with common brimstone, resumes the appearance and qualities of crude antimony.

The antimonial metal is a medicine of the greatest power of any known substance; a quantity too minute to be sensible in the tenderest balance, is capable of producing violent effects, if taken dissolved, or in a soluble state. If given in such a form as to be immediately miscible with the animal fluids, it proves violently emetic; if so managed as to be more slowly acted on, cathartic; and in either case, if the dose be extremely small, diaphoretic. Thus, though vegetable acids extract so little from this metal, that the remainder seems to have lost nothing of its weight, the tinctures prove in large doses strongly emetic, and in smaller ones powerfully diaphoretic. The regulus has been cast into the form of pills, which acted as violent cathartics, though without suffering any sensible diminution of weight in their passage through the body; and this repeatedly for a great number of times.

This metal, divested of the inflammable principle which it has in common with other metallic bodies that are reducible to a calx, becomes indissoluble and inactive. The calx, nevertheless, urged with a strong fire, melts into a glas, which is as easy of solution, and as violent in operation, as the regulus itself: the glas, thoroughly mixed with such substances as prevent its solubility, as wax, resin, and the like, is again rendered mild.

Vegetable acids, as has already been observed, dissolve but an extremely minute portion of this metal: the solution nevertheless is powerfully emetic and cathartic. The nitrous and vitriolic acids only corrode it into a powder, to which they adhere so slightly as to be separable in a considerable degree by water, and totally by fire, leaving the regulus in form of a calx similar to that prepared by fire alone. The marine acid has a very different effect: this reduces the regulus into a violent corrosive; and though it difficultly unites, yet it adheres so closely as not to be separable by any ablution, nor by fire, the regulus arising along with it. The nitrous or vitriolic acids expel the marine, and thus reduce the corrosive into a calx similar to the foregoing.

Sulphur remarkably abates the power of this metal; and hence crude antimony, in which the regulus Ius appears to be combined with sulphur, from one-fourth to one-half its weight, proves altogether mild. If a part of the sulphur be taken away by such operations as do not destroy or calcine the metal, the remaining mass becomes proportionally more active.

The sulphur of antimony may be expelled by deflagration with nitre: the larger the quantity of nitre, to a certain point, the more of the sulphur will be dissipated, and the preparation will be the more active. If the quantity of nitre be more than sufficient to consume the sulphur, the rest of it, deflagrating with the inflammable principle of the regulus itself, renders it again mild.

The sulphur of antimony is likewise absorbed in fusion by certain metals and by alkaline salts. These last, when united with sulphur, prove a menstruum for all the metals (zinc excepted); and hence, if the fusion be long continued, the regulus is taken up, and rendered soluble in water.

From these particulars with respect to antimony, it may naturally be concluded, that it not only furnishes us with an useful and active medicine, but that it may also be exhibited for medical purposes under a great variety of different forms, and that the effects of these will be considerably diversified. And this has in reality been the case. For further information respecting antimony, and its uses in medicine, we refer our readers to the articles Antimony; Materia Medica, p. 653, &c.; and Chemistry-Index. But although there is perhaps no preparation there mentioned, which is not fitted to serve some useful purpose; yet the colleges both of London and Edinburgh have now restricted the number of preparations in their pharmacopoeias to a few only. And it is highly probable, that from the proper employment of them, every useful purpose to be answered by antimony may be accomplished.

Calcined antimony. L.

Take of antimony, powdered, eight ounces; nitre, powdered, two pounds. Mix them, and cast the mixture by degrees into a red hot crucible. Burn the white matter about half an hour; and, when cold, powder it; after which wash it with distilled water.

In the last edition of the London pharmacopoeia this preparation had the name of calx of antimony; and it may be considered as at least very nearly approaching to some other antimonials of the old pharmacopoeias, particularly to the nitrated diaphoretic antimony, washed ditto, and fibitated nitre; none of which are now received as separate formulas of our pharmacopoeia, and indeed even the calx of antimony itself, at least as thus prepared, has now no place in the Edinburgh pharmacopoeia.

The calx of antimony, when freed by washing from the saline matter, is extremely mild, if not altogether inactive. Hoffman, Lemery, and others, assure us, that they have never experienced from it any such effects as its usual title imports: Boerhaave declares, that it is a mere metallic earth, entirely destitute of all medicinal virtue: and the committee of the London college admit that it has no sensible operation. The common dose is from five grains to a scruple, or half a dram; though Wilson relates, that he has known it given by half ounces, and repeated two or three times a day, for several days together.

Some report that this calx, by keeping for a length of time, contracts an emetic quality: From whence it has been concluded, that the powers of the reguline part are not entirely destroyed; that the preparation has the virtues of other antimonials which are given as alternatives; that is, in such small doses as not to stimulate the prime vice; and that therefore diaphoretic antimony, or calcined antimony, as it is now more properly styled, is certainly among the mildest preparations of that mineral, and may be used for children, and similar delicate constitutions where the stomach and intestines are easily affected. The observations, however, from which these conclusions are drawn, does not appear to be well founded: Ludovici relates, that after keeping the powder for four years, it proved as mild as at first: and the Strasbourg pharmacopoeia, with good reason, suspects, that where the calx has proved emetic, it had either been given in such cases as would of themselves have been attended with this symptom (for the great alexipharmic virtues attributed to it have occasioned it to be exhibited even in the more dangerous malignant fevers, and other disorders which are frequently accompanied with vomiting); or that it had not been sufficiently calcined, or perfectly freed from such part of the regulus as might remain uncalcined. The uncalcined part being groser than the true calx, the separation is effected by often washing with water, in the same manner as directed for separating earthy powders from their groser parts.

It has been observed, that when diaphoretic antimony is prepared with nitre abounding with sea-salt, of which all the common nitre contains some portion, the medicine has proved violently emetic. This effect is not owing to any particular quality of the sea-salt, but to its quantity, by which the proportion of the nitre to the antimony is rendered less.

The nitrum fibiatum, as it was called, is produced by the deflagration of the sulphur of the antimony with the nitre, in the same manner as the sal polychroa, from which it differs no otherwise than in retaining some portion of the antimonial calx.

Notwithstanding the doubts entertained by some respecting the activity of the antimonial calcinatum, yet the London college have in our opinion done right in retaining it. For while it is on all hands allowed that it is the mildest of our antimonials, there are some accurate observers who consider it as by no means inefficacious. Thus Dr Heald tells us, that he has been in the habit of employing it for upwards of 40 years, and is much deceived, if, when genuine, it be not productive of good effects.

Nitrated calx of antimony. E.

Take of antimony calcined for making the glass of antimony, and nitre, equal weights. Having mixed, and put them into a crucible, let them be heated, so that the matter shall be of a red colour for an hour; then let it be taken out of the crucible, and, after beating it, wash it repeatedly with warm water till it be insipid.

Although this preparation agrees nearly in name with the the preceding, and has been considered as being nearly a complete calx of antimony, yet there can be no doubt that it is a medicine of a much more active nature than the former; and in place of being one of the mildest of the antimonials, it often operates with great violence when given in doses of a few grains only.

But as the effects of every preparation of antimony, not already conjoined with an acid, must depend on the quantity and condition of the acid in the stomach, so the ablation of the base of the nitre in this process gives full power to the acid of the stomach to act as far as possible on the calx; whereas, when the unwashed calx is employed, a great quantity of the acid in the stomach is neutralized by the alkaline base of the nitre adhering to the calx. The nitrated calx of antimony is supposed to be nearly the same with the article which has been so much celebrated, and has had such an extensive sale under the title of Dr. James's fever powder. And it was as an article which might be employed in the place of James's powder, that the Edinburgh college introduced this into their pharmacopoeia. There is, however, reason to believe, that the preparation of James's powder is somewhat different from that here directed; but their effects, as far as our observation goes, appear to be very nearly the same.

The nitrated calx of antimony has been thought by some preferable to emetic tartar, where the permanent effects of a long-continued nausea are required, and where we wish our antimonials to pass the pylorus and produce purging. But, like every other preparation where the reguline part is only rendered active by the acid in the stomach, the nitrated calx of antimony is in all cases of uncertain operation: sometimes proving perfectly inert, and at other times very violent in its effects. The dose is generally 10 or 12 grains, and this is often given all at once; an inconvenience not attending the emetic tartar; the quantity and effects of which we can generally measure with surprising minuteness.

There is, however, reason to believe, that by means of James's powder, and the nitrated calx, an artificial termination of fever is sometimes accomplished, and that too more frequently than by emetic tartar. This perhaps may sometimes be the consequence of the violence with which they operate. At the same time it must be admitted, that even the most violent operation by no means ensues an immediate recovery, but that on the contrary it is sometimes manifestly attended with bad effects.

**Crocus of antimony.**

Take of antimony, powdered; nitre, powdered, of each one pound; sea-salt, one ounce. Mix, and put them by degrees into a red-hot crucible, and melt them with an augmented heat. Pour out the melted matter; and, when cold, separate it from the scoriae. L.

Equal parts of antimony and nitre are to be injected by degrees into a red-hot crucible; when the detonation is over, separate the reddish metallic matter from the whitish crust; beat it into a powder, and edulcorate it by repeated washings with hot water, till the water comes off insipid. E.

**Muriated antimony.** L.

Take of the crocus of antimony, powdered; vitriolic acid, each one pound; dry sea-salt, two pounds. Pour the vitriolic acid into a retort, adding by degrees the sea-salt and crocus of antimony, previously mixed; then distil in a sand-bath. Let the distilled matter be exposed to the air several days, and then let the fluid part be poured off from the dregs.

**Butter of antimony.** E.

Take of crude antimony, one part; corrosive sublimate of mercury, two parts. Grind them first separately; then thoroughly mix them together, taking the utmost care to avoid the vapours. Put the mixture into a coated glass retort (having a short wide neck), so as to fill one half of it: the retort being placed in a sand-furnace, and a receiver adapted to it, give first a gentle heat, that only a dewy vapour may arise: the fire being then increased, an oily liquor will ascend and congeal in the neck of the retort, appearing like ice, which is to be melted down by a live coal cautiously applied. This oily matter is to be rectified in a glass retort into a pellucid liquor.

The process here directed by the Edinburgh college, and which is nearly the same with what stood in the former edition of the London pharmacopoeia, is extremely dangerous, inasmuch that even the life of the operator, though tolerably versed in common pharmacy, may be much endangered for want of due care. Boerhaave relates, that one, who from the title he gives him is not to be supposed inexpert in chemical operations, or unacquainted with the danger attending this, was suffocated for want of proper care to prevent the bursting of the retort. The fumes which arise, even upon mixing the antimony with the sulphate, are highly noxious, and sometimes issue so copiously and suddenly, as very difficultly to be avoided. The utmost circumspection therefore is necessary.

The caustic, or bitter as it is called, appears to be a solution of the metallic part of the antimony in the marine acid of the sublimate; the sulphur of the antimony, and the mercury of the sublimate, remain at the bottom of the retort united into an ethiops. This solution does not succeed with spirit of salt in its liquid state, and cannot be effected, unless (as in the case of making sublimate) either the acid be highly concentrated, and both the ingredients strongly heated; or when the antimony is exposed to the vapours of the acid distilled from the black calx of manganese. By this last process a perfect solution of the regulus of antimony in the muriatic acid is effected. Of this more simple, more safe, and less expensive method of preparing muriated antimony, an account is given by Mr Ruffel in the Transactions of the Royal Society of Edinburgh.

If regulus of antimony were added in the distillation of spirit of sea-salt without water, a solution would also be made.

The method, however, now directed by the London college, in which vitriolic acid and sea-salt are employed to give a double elective attraction, is perhaps to be considered as preferable to any of the others. In this they have followed very nearly the directions given in the Pharmacopoeia Suecica, which are taken from the process of Mr Scheele.

When the coagulated matter that arises into the neck of the retort is liquefied by the moisture of the air, it proves less corrosive than when melted down and rectified by heat; though it seems, in either case, to be sufficiently strong for the purposes of consuming fungous flesh and the callous lips of ulcers. It is remarkable, that though this saline concrete readily and almost entirely dissolves by the humidity of the air, only a small quantity of white powder separating, it nevertheless will not dissolve on putting water to it directly; even when previously liquefied by the air, the addition of water will precipitate the solution. And accordingly, by the addition of water is formed that once celebrated article known by the title of mercurius vita, or Algeroth's powder. This preparation, though never used by itself, is employed both by the Edinburgh and by some of the foreign colleges, in the formation of emetic tartar, the most useful of all the antimonials. And although chemists are not altogether agreed with regard to the best mode of making the tartarized antimony, yet we shall afterwards have occasion to observe, when treating of that article, that the preparation of it from the muriated antimony, or rather from its precipitate (Algeroth's powder), is perhaps the best mode which has yet been practised. And were it even with no other preparation than this, a safe, easy, and cheap method of forming a muriated antimony, may be considered as an important improvement in our pharmacopoeias.

Antimonial powder. L.

Take of antimony, coarsely powdered, hawthorn shavings, each two pounds; mix, and put them into a wide red-hot iron pot, stirring constantly till the mass acquires a grey-colour. Powder the matter when cold, and put it into a coated crucible. Lute to it another crucible inverted, which has a small hole in its bottom: augment the fire by degrees to a red heat, and keep it so for two hours. Lastly, reduce the matter, when cold, to a very fine powder.

In this preparation, the metallic part of the antimony in a state of calx will be united with that part of the hawthorn which is indestructible by the action of fire, viz. its absorbent earth. If this powder be properly prepared, it is of a white colour. It is a mild antimonial preparation, and is given as an alternative from three to six grains for a dose. In this quantity, however, it sometimes creates nausea, and even vomits. In larger doses it proves emetic, and operates by stool.

Precipitated sulphur of antimony. L.

Take of antimony, powdered, two pounds; water of pure kali, four pints; distilled water, three pints; Mix, and boil them with a slow fire for three hours, constantly stirring, and adding the distilled water as it shall be wanted; strain the hot ley through a double linen cloth, and into the liquor, whilst yet hot, drop by degrees as much diluted vitriolic acid as is sufficient to precipitate the sulphur. Wash off, with warm water, the vitriolated kali.

Golden sulphur of antimony. E.

Boil, in an iron pot, four pounds of caustic ley diluted with three pints of water, and throw in by degrees two pounds of powdered antimony; keeping them continually stirring with an iron spatula for three hours, over a gentle fire, and occasionally supplying more water. The liquor loaded with the sulphur of antimony being then strained through a woollen cloth, drop into it gradually, while it continues hot, so much spirit of nitre, diluted with an equal quantity of water, as shall be sufficient to precipitate the sulphur, which is afterwards to be carefully washed with hot water.

The foregoing preparations are not strictly sulphurs; they contain a considerable quantity of the metallic part of the antimony, which is reducible from them by proper fluxes. These medicines must needs be liable to great variation in point of strength; and in this respect they are, perhaps, the most precarious, though some have affirmed that they are the most certain, of the antimonial medicines.

They prove emetic when taken on an empty stomach, in a dose of four, five, or six grains; but at present they are scarcely prescribed with this intention; being chiefly used as alternative deobstruents, particularly in cutaneous disorders. Their emetic quality is easily blunted, by making them up into pills with re- fins or extracts, and giving them on a full stomach: with these cautions they have been taken in the quantity of 16 grains a-day, and continued for a considerable time, without occasioning any disturbance upwards or downwards. As their strength is precarious, they should be taken at first in very small doses, and increased by degrees according to their effect.

A composition of the golden sulphur, with sweet mercury, has been found a powerful, yet safe alterative, in cutaneous disorders; and has completed a cure after salivation had failed. In venereal cases, likewise, this medicine has produced excellent effects. A mixture of equal parts of the sulphur and calomel (well triturated together, and made into pills with extracts, &c.) may be taken from four to eight or ten grains, morning and night; the patient keeping moderately warm, and drinking after each dose a draught of a decoction of the woods, or other similar liquor. This medicine generally promotes perspiration, scarcely occasioning any tendency to vomit or purge, or affecting the mouth.

**Tartarized antimony. L.**

Take of crocus of antimony, powdered, one pound and an half; crystals of tartar, two pounds; distilled water, two gallons: boil in a glass vessel about a quarter of an hour; filter through paper, and set aside the strained liquor to crystallize.

**Emetic tartar. E.**

Take of the butter of antimony what quantity you choose; pour it into warm water, in which so much of the purified vegetable fixed alkali has been previously dissolved, that the antimonial powder may be precipitated, which, after being well washed, is to be dried. Then to five pounds of water add of this powder nine drams, of crystals of tartar, beat into a very fine powder, two ounces and a half; boil for a little till the powders be dissolved. Let the strained solution be slowly evaporated in a glass vessel to a pellicle, so that crystals may be formed.

We have here two modes of making the most common, and perhaps we may add the most useful, of all the antimonial preparations, long known in the shops under the name of *emetic tartar*. These modes differ considerably from each other; but in both, the reguline part of the antimony is united with the acid of the tartar. It is perhaps difficult to say to which mode of preparation the preference is to be given; for on this subject the best chemists are still divided in their opinion. The mode directed by the London college is nearly the same with that in former editions of their pharmacopoeia, while that now adopted by the Edinburgh college in which they have nearly followed the Pharmacopoeia Rossica, is of later date. That in both ways a good emetic tartar may be formed, is very certain; but in our opinion, when it is formed of the precipitate from the muriatic acid, or the *poultre d'Algerotis*, as it has been called, there is the least chance of its being uncertain in its operation; and this method comes recommended to us on the authority of Bergman, Scheele, and some other of the first names in chemistry. Bergman advises, that the calx be precipitated by simple water, as being least liable to variation; and this is the direction followed in the Pharmacopoeia Rossica. But when the calx is precipitated by an alkaline ley, as is directed by the Edinburgh college, it is more certainly freed from the muriatic acid, and will of course be milder.

In the after part of the process, whether precipitate or crocus have been used, the quantity of the antimonial ought always to be some drams more than is absolutely necessary for saturating the acid of tartar, so that no crystals may shoot which are not impregnated with the active metallic part of the antimony. And in order to secure an uniform strength, some attention is necessary in collecting the crystals, as some may contain more metal than others. After they are all separated from the liquor, they ought to be heat together in a glass mortar into a fine powder, that the medicine may be of uniform strength.

Emetic tartar is, of all the preparations of antimony, the most certain in its operation.

It will be sufficient, in considering the medicinal effects of antimonials, that we should observe, once for all, that their emetic property depends on two different conditions of the reguline part: the first is where the reguline part is only active, by being rendered so from meeting with an acid in the stomach: the second is where the reguline part is already joined with an acid, rendering it active. It is obvious, that those preparations, reducible to the first head, must always be of uncertain operation. Such then is the equal uncertainty in the chemical condition and medicinal effects of the croci, the hepata, and the calces; all of which processes are different steps or degrees of freeing the reguline part from sulphur and phlogiston. It is equally plain, that the preparations coming under the second head must be always constant and certain in their operation. Such a one is emetic tartar, the dose and effects of which we can measure with great exactness.

The title of this medicine expresses its principal operation. It is one of the best of the antimonial emetics, acting more powerfully than the quantity of crocus contained in it would do by itself, though it does not so much ruffle the constitution. And indeed antimonials in general, when thus rendered soluble by vegetable acids, are more safe and certain in their effects than the violent preparations of that mineral exhibited by themselves; the former never varying in their action from a difference in the food taken during their use, or other similar circumstances; which occasioning more or less of the others to be dissolved, make them operate with different degrees of force. Thus, crude antimony, where acid food has been liberally taken, has sometimes proved violently emetic; whilst in other circumstances it has no such effect.

The dose of emetic tartar, when designed to produce the full effect of an emetic, is from two to four grains. It may likewise be advantageously given in much smaller doses as a nauseating and sudorific medicine.

**Vitrified antimony. L.**

Take of powdered antimony, four ounces. Calcine it in a broad earthen vessel, with a fire gradually raised, stirring with an iron rod until it no longer emits a fulphurous smoke. Put this powder into a crucible, so as to fill two-thirds of it. A cover being fitted on, make a fire under it, at first moderate, afterwards stronger, until the matter be melted. Pour out the melted glaas.

Glaas of antimony. E.

Strew antimony, beat into a coarse powder like sand, upon a shallow unglazed earthen vessel, and apply a gentle heat underneath, that the antimony may be heated slowly; keeping it at the same time continually stirring to prevent it from running into lumps. White vapours of a sulphurous smell will arise from it. If they cease to exhale with the degree of heat first applied, increase the fire a little, so that vapours may again arise: go on in this manner, till the powder, when brought to a red heat, exhales no more vapours. Melt the calx in a crucible with an intense heat, till it assumes the appearance of melted glaas: then pour it out on a heated brass plate or dish.

The calcination of antimony, in order to procure transparent glaas, succeeds very slowly, unless the operator be wary and circumjacent in the management of it. The most convenient vessel is a broad shallow dish, or a smooth flat tile, placed under a chimney. The antimony should be the purer sort, such as is usually found at the apex of the cones; this, grossly powdered, is to be evenly spread over the bottom of the pan, so as not to lie above a quarter of an inch thick on any part. The fire should be at first no greater than is just sufficient to raise a fume from the antimony, which is to be now and then stirred; when the fumes begin to decay, increase the heat, taking care not to raise it so high as to melt the antimony, or run the powder into lumps; after some time the vessel may be made red-hot, and kept in this state until the matter will not, upon being stirred, any longer fume. If this part of the process be duly conducted, the antimony will appear in an uniform powder, without any lumps, and of a grey colour.

With this powder fill two-thirds of a crucible, which is to be covered with a tile, and placed in a wind-furnace. Gradually increase the fire till the calx be in perfect fusion, when it is to be now and then examined by dipping a clean iron wire into it. If the matter which adheres to the end of the wire appears smooth and equally transparent, the vitrification is completed, and the glaas may be poured out upon a hot smooth stone or copperplate, and suffered to cool slowly to prevent its cracking and flying in pieces. It is of a transparent yellowish red colour.

The glaas of antimony usually met with in the shops, is said to be prepared with certain additions; which may, perhaps, render it not so fit for the purpose here designed. By the method above directed, it may be easily made of the requisite perfection without any addition.

As antimony may be rendered nearly or altogether inactive by calcination, it might be expected that the calx and glaas of the present process would be likewise inert. But here the calcination is far less perfect than in the other case, where the inflammable principle of the regulus is totally burnt out by deflagration with nitre; there the calx is of perfect whiteness, and a glaas made from that calx (with the addition of any saline flux, for of itself it will not vitrify) has little colour; but here so much of the inflammable principle is left, that the calx is grey, and the glaas of a high colour. The calcined antimony is said by Boerhaave to be violently emetic. Experience has shown that the glaas is so, inasmuch as to be unsafe for internal use. At present it is chiefly employed in forming some other antimonial preparations, particularly the cerated glaas of antimony, the next article to be mentioned; and the wine of antimony, afterwards to be treated of under the head of wines. It is also not unfrequently employed in the formation of emetic tartar; and it was directed for that purpose in the last edition of the Edinburgh pharmacopoeia, being perhaps even superior to the crocus of antimony.

Cerated glaas of antimony. E.

Take of yellow wax, a dram; glaas of antimony, reduced into powder, an ounce. Melt the wax in an iron vessel, and throw into it the powdered glaas; keep the mixture over a gentle fire for half an hour, continually stirring it; then pour it out on paper, and when cold grind it into powder.

The glaas melts in the wax with a very gentle heat; after it has been about twenty minutes on the fire, it begins to change its colour, and in ten more comes near to that of Scotch snuff; which is a mark of its being sufficiently prepared; the quantity set down above loses about one dram of its weight in the process.

This medicine was for some time much esteemed in dysenteries: several instances of its good effects in these cases may be seen in the fifth volume of the Edinburgh Essays, from which the above remarks on the preparations are taken. The dose is from two or three grains to twenty, according to the age and strength of the patient. In its operation, it makes some persons sick and vomit; it purges almost every one; though it has sometimes effected a cure without occasioning any evacuation or sickness. It is now, however, much less used than formerly.

Mr Geoffroy gives two pretty singular preparations of glaas of antimony, which seem to have some affinity with this. One is made by digesting the glaas, very finely levigated, with a solution of mastic made in spirit of wine, for three or four days, now and then shaking the mixture; and at last evaporating the spirit so as to leave the mastic and glaas perfectly mixed. Glaas of antimony thus prepared, is said not to prove emetic, but to act merely as a cathartic, and that not of the violent kind. A preparation like this was first published by Hartman, under the name of Chylifta.

The other preparation is made by burning spirit of wine on the glaas three or four times, the powder being every time exquisitely rubbed upon a marble. The dose of this medicine is from ten grains to 20 or 30; it is said to operate mildly both upwards and downwards, and sometimes to prove sudorific.

Ceruse of antimony. Brun.

Take of regulus of antimony, one part; nitre, three parts. Deflagrate them together in the manner directed for the calcined antimony.

The result of this process and that formerly directed for the calcined antimony are nearly the same.

It is not necessary to use so much nitre here as when... antimony itself is employed: for the sulphur which the crude mineral contains, and which requires for its distillation nearly an equal weight of nitre to the antimony, is here already separated. Two parts of nitre to one of the regulus are sufficient. It is better, however, to have an over, than an under, proportion of nitre, lest some parts of the regulus should escape being sufficiently calcined.

It may be proper to observe, that though crude antimony and the regulus yield the same calces, yet the salts separated in washing the calces are very different. As crude antimony contains common sulphur, the acid of the sulphur unites with the alkaline basis of the nitre, and the result is a neutral salt. As the regulus contains the phlogistic, or inflammable principle, but no sulphur, the nitre is alkalisied, as it would be by charcoal or such like inflammable bodies, and is at the same time rendered more acrimonious than the common alkaline salts; probably owing to the calx absorbing the air of the alkali. If only equal parts of the regulus and nitre be employed, and the fire kept up strong for an hour or more, the salt will prove more caustic than even the potential caustic of the shops. But the causticity of the salt will still be far greater, if, instead of the simple regulus of antimony, the martial regulus be used.

Kermes mineral. Suec.

Take of crude antimony, powdered, half a pound; fixed vegetable alkali, two pounds; boiling water, eight pounds. Boil them together in an iron pot for a quarter of an hour, continually stirring the mixture with an iron spatula, and filter as speedily as possible while it is hot. The filtered liquor, set in cool places, will soon deposit a powder, which must be repeatedly washed, first with cold and afterwards with warm water, until it be perfectly infusible.

This medicine has of late been greatly esteemed in France, especially under the names of Kermes mineral, pulvis Carthagenae, poudre des Chartreux, &c. It was originally a preparation of Glauber, and for some time kept a great secret, till at length the French king purchased the preparation from M. de la Ligerie, for a considerable sum, and communicated it to the public in the year 1720. In virtue, it is not different from the sulphurs above-mentioned; all of them owe their efficacy to a part of the regulus of the antimony, which the alkaline salt, by the mediation of the sulphur, renders soluble in water.

Chemists are, however, divided in their opinions with respect to the precise chemical condition of the reguline part in the preparations called hepata of antimony. Some have alleged that they contain not a particle of alkaline salt: it is at any rate certain, that the quantity and condition of the reguline part must vary according to the different proportions of the ingredients, the time of the precipitation, the greater or less degree of causticity of the alkali employed, and several other circumstances. At best, the whole of them are liable to the same uncertainty in their operation as the calces of antimony.

Panacea of antimony.

Take of antimony, six ounces; nitre, two ounces; common salt, an ounce and a half; charcoal, an ounce. Reduce them into a fine powder, and put the mixture into a red-hot crucible, by half a spoonful at a time, continuing the fire a quarter of an hour after the last injection: then either pour the matter into a cone, or let it cool in the crucible; which when cold must be broken to get it out. In the bottom will be found a quantity of regulus; above this a compact liver-coloured substance; and on the top a more spongy mass: this last is to be reduced into powder, edulcorated with water, and dried, when it appears of a fine golden colour.

This preparation is supposed to have been the basis of Lockyer's pills, which were formerly a celebrated purge. Ten grains of the powder, mixed with an ounce of white sugar-candy, and made up into a mass with mucilage of gum tragacanth, may be divided into an hundred small pills; of which one, two, or three, taken at a time, are said to work gently by stool and vomit. The compact liver-coloured substance, which lies immediately above the regulus, operates more severely. This last appears to be nearly of the same nature with the crocus of antimony, and the former with the golden sulphur.

Chap. XI. Preparations of silver.

Nitrated silver. L.

Take of silver, one ounce; diluted nitrous acid, four ounces. Dissolve the silver in the nitrous acid, in a glass vessel, over a sand-heat; then evaporate with an heat gently raised: afterwards melt the residuum in a crucible, that it may be poured into proper forms, carefully avoiding too great a heat.

Salt of silver, commonly called lunar caustic. E.

Take of purest silver, beat into plates, and cut in pieces, four ounces; weak nitrous acid, eight ounces; purest water, four ounces. Dissolve the silver in a phial with a gentle heat, and evaporate the solution to dryness. Then put the mass into a large crucible, and apply the heat, at first gently, but augment it by degrees till the mass flows like oil; then pour it into iron moulds, previously heated, and greased with tallow.

These processes do not differ in any material particular. But the name of nitrated silver is preferable to the more indefinite one of salt of silver.

Strong spirit of nitre will dissolve somewhat more than half its weight of pure silver; and the weaker of the aquafortes, formerly described, proportionally less, according to their quantity of pure nitrous acid. Sometimes this spirit contains a portion of the vitriolic or marine acids; which, however minute, renders it unfit for dissolving this metal, and should therefore be carefully separated before the solution be attempted. The method which the refiners employ for examining the purity of their aquafortis, and purifying it if necessary, is to let fall into it a few drops of a perfect solution of silver already made: if the liquor remain clear, and grow not in the least turbid or whitish, it is fit for use; otherwise, they add a small quantity more of the solution, which immediately turns the whole of a milky white colour; the mixture being then suffered to rest for some time, deposits a white sediment; from which it is warily decanted, examined afresh, and if need be, farther purified by a fresh addition of the solution.

The silver beat into thin plates, as directed in the second of the above processes, needs not be cut in pieces; the solution will go on the more speedily if they are only turned round into spiral circumvolutions, so as to be conveniently got into the glass, with care that the several surfaces do not touch each other. By this management, a greater extent of the surface is exposed to the action of the menstruum, than when the plates are cut in pieces and laid above each other. Good aquafortis will dissolve about half its weight of silver; and it is not advisable to use a greater quantity of the menstruum than is sufficient for effecting the solution, for all the surplus must be evaporated in the subsequent fusion.

It is necessary to employ very pure water; for if hard water were used in this process, the nitrous acid would forfeit a part of the silver to join with the calcareous earth of the imperfect nitrous selenite; whereby a part of the silver would be precipitated.

The crucible ought to be large enough to hold five or six times the quantity of the dry matter; for it bubbles and swells up greatly, and is consequently apt to run over. During this time, also, little drops are now and then spurted up, whose causticity is increased by their heat, against which the operator ought therefore to be on his guard. The fire must be kept moderate till this ebullition ceases, and till the matter becomes consistent in the heat that made it boil before; then quickly increase the fire till the matter flows thin at the bottom like oil, when it is to be immediately poured into the mould, without waiting till the fumes cease to appear; for when this happens, the preparation proves not only too thick to run freely into the mould, but likewise less corrosive than it is expected to be.

For want of a proper iron mould, one may be formed of tempered tobacco-pipe clay, not too moist, by making in a lump of it, with a smooth stick first greased, as many holes as there is occasion for; pour the liquid matter into these cavities, and when congealed take it out by breaking the mould. Each piece is to be wiped clean from the grease, and wrapped up in soft dry paper, not only to keep the air from acting on them, but likewise to prevent their corroding or discolouring the fingers in handling.

This preparation is a strong caustic; and is frequently employed as such for confining warts and other fleshly excrescences, keeping down fungous flesh in wounds or ulcers, and other similar uses. It is rarely applied where a deep ulcer is required, as in the laying open of impotheumations and tumors; for the quantity necessary for these purposes, liquefying by the moisture of the skin, spreads beyond the limits within which it is intended to operate.

The lunar pills.

Dissolve pure silver in aquafortis, as in the foregoing process; and after due evaporation, set the liquor aside to crystallize. Let the crystals be again dissolved in common water, and mixed with a solution of equal their weight of nitre. Evaporate this mixture to dryness, and continue the exsiccation with a gentle heat, keeping the matter constantly stirring until no more fumes arise.

Here it is necessary to continue the fire till the fumes entirely cease, as more of the acid is required to be dissipated than in the preceding process. The preparation is, nevertheless, in taste very sharp, intensely bitter and nauseous; applied to ulcers, it acts as a caustic, but it is much milder than the foregoing. Boerhaave, Boyle, and others, commend it highly in hydroptic cases. The former assures us, that two grains of it made into a pill with crumbs of bread and a little sugar, and taken on an empty stomach (some warm water, sweetened with honey, being drank immediately after), purge gently without griping, and bring away a large quantity of water, almost without the patient's perceiving it; that it kills worms, and cures many inveterate ulcerous disorders. He nevertheless cautions against using it too freely, or in too large a dose; and observes, that it always proves corrosive and weakening, especially to the stomach.

Chap. XII. Preparations of iron.

Ammoniacal iron. L.

Take of iron filings, one pound; sal ammoniac, two pounds. Mix, and sublime. What remains at the bottom of the vessel mix by rubbing together with the sublimed matter, and again sublime.

Martial flowers, commonly called Ens Veneris. E.

Take of colcothar of martial vitriol, washed and well dried; sal ammoniac, equal weights. Having mixed them well, sublime.

Though the mode of preparation directed by the two colleges is here different, yet the preparation is fundamentally the same; and it is perhaps difficult to say which mode of preparation is to be preferred as the easiest and best.

The name of ens veneris has by some been very improperly applied to this preparation, as it contains not a particle of copper. The proper ens veneris is prepared from the blue vitriol; but, as we shall soon see, is often not materially different from the martial flowers.

The success of this process depends principally on the fire being hastily raised, that the sal ammoniac may not sublime before the heat be sufficient to enable it to carry up a sufficient quantity of the iron. Hence glass vessels are not so proper as earthen or iron ones; for when the former are used, the fire cannot be raised quickly enough, without endangering the breaking of them. The most convenient vessel is an iron pot, to which may be fitted an inverted earthen jar, having a small hole in its bottom to suffer the elastic vapours, which arise during the operation, to escape. It is of advantage to thoroughly mix the ingredients together, moisten them with a little water, and then gently dry them; and to repeat the pulverization, humectation, and exsiccation, two or three times, or oftener. If this method be followed, the sal ammoniac may be increased to three times the quantity of the iron, or farther; and a single sublimation will often be sufficient to raise flowers of a very deep orange colour.

This preparation is supposed to be highly aperient and attenuating; though no otherwise so than the rest of the chalybeates, or at most only by virtue of the saline matter joined to the iron. It has been found of service in hysterical and hypochondriacal cases, and in distempers proceeding from a laxity and weakness of the solids, as the tickets. It may be conveniently taken in the form of a bolus, from two or three grains to ten; it is nauseous in a liquid form (unless in spirituous tincture); and occasions pills to swell and crumble, except such as are made of the gums.

**Rust of iron. L.**

Take of iron-filings, one pound; expose them to the air, often moistening them with water, until they be corroded into rust; then powder them in an iron mortar, and wash off with distilled water the very fine powder. But the remainder, which cannot by moderate rubbing be reduced into a powder capable of being easily washed off, must be moistened, exposed to the air for a longer time, and again powdered and washed as before. Let the washed powder be dried.

**Rust of iron, commonly called prepared iron filings. E.**

Set purified filings of iron in a moist place, that they may turn to rust, which is to be ground into an impalpable powder.

The cleansing of iron filings by means of a magnet is very tedious, and does not answer so well as might be expected; for if they be rusty, they will not be attracted by it, or not sufficiently; nor will they by this means be entirely freed from brass, copper, or other metallic substances which may adhere to them. It appears from the experiments of Henckel, that if iron be mixed by fusion with even its own weight of any of the other metals, regulus of antimony alone excepted, the compound will be vigorously attracted by the loadstone. The rust of iron is to be procured at a moderate rate from the dealers in iron, free from any impurities, except such as may be washed off by water.

The rust of iron is preferable as a medicine to the calces or croci, made by a strong fire. Hoffman relates, that he has frequently given it with remarkable success in obstinate chlorotic cases accompanied with excessive headache and other violent symptoms; and that he usually joined with it pimpinella, arum root, and salt of tartar, with a little cinnamon and sugar. The dose is from four or five grains to twenty or thirty. Some have gone as far as a dram; but all the preparations of this metal answer best in small doses, which should rather be often repeated than enlarged.

**Tartarized iron. L.**

Take of filings of iron, one pound; powdered crystals of tartar, two pounds. Mix them with distilled water into a thick paste. Expose it to the air in an open earthen vessel for eight days; then grind the matter, dried in a bath of sand, to a very fine powder.

This is an useful preparation of iron, in which that metal is chiefly brought to a saline state by means of the cream of tartar. It has now for the first time a place in the London pharmacopoeia; but it had before been introduced into some of the foreign ones, particularly the pharmacopoeia Genevensis, under the title of *mars tartarifatus*; and indeed it is almost precisely the same with the *mars solubilis* of the old editions of the Edinburgh pharmacopoeia.

**Vitriolated iron. L.**

Take of filings of iron, vitriolic acid, each eight ounces; distilled water, three pints. Mix them in a glass vessel; and when the effervescence has ceased, place the mixture for some time upon hot sand; then pour off the liquor, straining it through paper; and after due exhalation set it aside to crystallize.

**Vitriol of iron, or salt of steel. E.**

Take of purified filings of iron, six ounces; vitriolic acid, eight ounces; water, two pounds and a half. Mix them; and when the effervescence ceases, let the mixture stand for some time upon warm sand; then strain the liquor through paper, and after due evaporation set it aside to crystallize.

During the dissolution of the iron an elastic vapour rises, which on the approach of flame catches fire and explodes, so as sometimes to burst the vessel. To this particular therefore the operator ought to have due regard.

This vapour is also noxious to animal life. It is the inflammable air of Dr Priestley.

The chemists are seldom at the trouble of preparing this salt according to the directions above given; but in its stead substitute common green vitriol, purified by solution in water, filtration, and crystallization. The only difference between the two is, that the common vitriol contains somewhat more metal in proportion to the acid; and hence in keeping, its green colour is much sooner debauched by a rusty brownish cast. The superfluous quantity of metal may be easily separated, by suffering the solution of the vitriol to stand for some time in a cold place; when a brownish yellowish sediment will fall to the bottom; or it may be perfectly dissolved, and kept suspended by a suitable addition of oil of vitriol. If the vitriol be suspected to contain any cuprous matter, which the common English vitriol seldom does, though almost all the foreign vitriols do, the addition of some bright iron wire to the solution will both discover, and effectually separate, that metal; for the acid quits the copper to dissolve a proportionate quantity of the iron; and the copper, in its separation from the acid, adheres to the undissolved iron, and forms a skin of a true copper colour on its surface. Even a vitriol of pure copper may, on this principle, be converted into a pure vitriol of iron.

But though the vitriolic acid appears in this operation to have so much stronger a disposition to unite with iron than with copper, that it totally rejects the latter when the former is presented to it; the operator may nevertheless give a dangerous impregnation of copper to the purest and most saturated solution of iron in the vitriolic acid, by the use of copper vessels. If the martial solution be boiled in a copper vessel, it never fails to dissolve a part of the copper, distinguishable by its giving a cuprous stain to a piece of bright iron immersed in it. By the addition of the iron, the copper copper is separated; by boiling it again without iron, more of the copper is dissolved; and this may in like manner be separated by adding more iron.

The salt of steel is one of the most efficacious preparations of this metal; and not unfrequently made use of in cachectic and chlorotic cases, for exciting the uterine purgations, strengthening the tone of the viscera, and destroying worms. It may be conveniently taken in a liquid form, largely diluted with water: Boerhaave directs it to be dissolved in an hundred times its weight of water, and the solution to be taken in the dose of twelve ounces on an empty stomach, walking gently after it. Thus managed, he says, it opens the body, proves diuretic, kills and expels worms, tinges the excrements black, or forms them into a matter like clay, strengthens the fibres, and thus cures many different distempers. The quantity of vitriol in the above dose of the solution is fifty-seven grains and a half; but in common practice, such large doses of this strong chalybeate are never ventured on. Four or five grains, and in many cases half a grain, are sufficient for the intention in which chalybeate medicines are given. Very dilute solutions, as that of a grain of the salt in a pint of water, may be used as succedanea to the natural chalybeate waters, and will in many cases produce similar effects.

Colcothar of vitriol. E.

Let calcined vitriol be urged with a violent fire till it becomes of a very red colour.

In this preparation, the iron which had been brought to a saline state by means of the acid of vitriol, is again deprived of that acid by the action of fire. It may be considered therefore as differing in nothing from the residuum which remains in the retort, when vitriolic acid is distilled from martial vitriol. The colcothar is very rarely employed by itself for medical purposes; but it is used in the preparation of some other chalybeates, particularly the martial flowers, when prepared according to the method directed by the Edinburgh college.

Martial athiops. Gen.

Take of the rust of iron, as much as you please; olive oil, a sufficient quantity to make it into a paste. Let this be distilled in a retort by a strong fire to dryness. Keep the residuum reduced to a fine powder in a close vessel.

An article under this name had formerly a place in some of the old pharmacopoeias, and is described by Lemery in the Memoirs of the French Academy; but it was formed by a tedious process, continued for several months by the aid of water. Here the process is much shorter, and is supposed to give nearly the same product. Some have recommended it, on the supposition that the iron is here obtained in a very subtile state; but it is not in general supposed to have any advantage over the other more common chalybeates.

Opening and astringent crocus of iron.

These are prepared by mixing iron filings with twice their weight of powdered sulphur, deflating in a red-hot crucible; and in the one case keeping the preparation over the fire till it assumes a red colour; in the other, by reverberating it for a long time in the preparation and extreme degree of heat.

Preparations under these names still retain a place in some of the foreign pharmacopoeias, but they are variously prepared. They may, however, be considered as possessing the same medical powers: and although the preparations mentioned above probably differ from each other in their virtues, yet that difference is not of such a nature as is imported by the titles by which they are usually distinguished. For all the preparations of iron probably act by an astringent quality; and that which is above denominated the astringent crocus has probably least effect in that way. At one period, these preparations were not unfrequently in use; and they were given in the form of bolus, electuary, or pill, from a few grains to a scruple; but among us they are at present so little in use as to have no place in our pharmacopoeias.

Chap. XIII. Preparations of Mercury.

We have already treated of mercury in various parts of our work as we found occasion, and what we have already discussed it is unnecessary to repeat. See Mercury, Chemistry-Index, Materia Medica, p. 653, Metallurgy, and Quicksilver. On the whole, it appears evident that there is no article which has been employed for medical purposes in a greater variety of forms. The colleges of London and Edinburgh have admitted into their pharmacopoeias only a few of these; but from the selection they have made, there is reason to believe that every useful purpose for which mercury has been employed may be answered; and these purposes are both numerous and considerable. For it is at least very generally allowed among intelligent practitioners, that there are few articles kept in the shops of our apothecaries which can be considered as so extensively useful.

Mercury or quicksilver, in its crude state, is a ponderous metallic fluid, totally volatile in a strong fire, and calcinable by a weaker one (though very difficultly) into a red powdery substance. It dissolves in the nitrous acid, is corroded by the vitriolic, but not acted on by the marine in its liquid state; it nevertheless may be combined with this last skillfully applied in the form of fume. Quicksilver unites by trituration with earthly, unctuous, resinous, and other similar substances, so as to lose its fluidity: triturated with sulphur, it forms a black mass, which by sublimation changes into a beautiful red one.

For the general virtues of the mercurial preparations, see some of the articles above referred to, and Medicine. Here we shall only observe, that while in certain circumstances they act as stimulants, and even as corrosives, to the parts to which they are applied; under a different management, when introduced into the habit, they seem to forward circulation through even the smallest and most remote vessels of the body; and may be so managed as to promote all the excretions. But while they thus operate as a powerful stimulus to the sanguiferous, and probably also to the lymphatic system, they seem to exert but little influence on the nervous system. By this means they prove eminently serviceable in some inveterate chronic disorders, proceedings from obstinate obstructions of the glands. Crude mercury has has no effect this way. Resolved into fume, or divided into minute particles, and prevented from reuniting by the interposition of other substances, it operates very powerfully, unless the dividing body be sulphur, which restrains its action. Combined with a small quantity of the mineral acids, it acts effectually, though in general mildly; with a larger, it proves violently corrosive.

**Purified quicksilver. L.**

Take of quicksilver, filings of iron, each four pounds. Rub them together, and distil from an iron vessel.

As in the distillation of quicksilver glass retorts are very liable to be broken, an iron one is here with propriety directed; and by the addition of the filings of iron, matters which might otherwise arise with the quicksilver will be more apt to be detained in the retort. But still this happens so readily, even merely with that degree of heat which is necessary to elevate the mercury, that it is very doubtful whether much advantage be obtained from this process; and accordingly it has now no place in the pharmacopoeia of the Edinburgh college.

**Acetated quicksilver. L.**

Take of purified quicksilver, one pound; diluted nitrous acid, two pounds; water of kali, as much as is sufficient. Mix the quicksilver with the acid in a glass vessel, and dissolve it in a sand-bath; then drop in by degrees the water of kali, that the calx of quicksilver may be precipitated; wash this calx with plenty of distilled water, and dry it with a gentle heat. These things being done, take of the calx of quicksilver, above described, one pound; acetic acid, as much as is necessary to dissolve the calx. Mix them in a glass vessel; and the solution being completed, strain it through paper; then evaporate it till a pellicle appears, and set it aside to crystallize. Keep these crystals in a vessel cloathed.

Of all the saline preparations of mercury, it has long been the opinion of the best chemists, that those in which it was brought to a saline form, by means of acetic acid, would be the mildest; and such a preparation was conjectured to be the basis of a celebrated pill, prepared and sold by Mr Keyser. It was, however, found to be a very difficult matter to imitate his pill, or to obtain a combination of mercury with the acetic acid; but not long since, the process for preparing these pills was published by authority at Paris, after being purchased by the French king. The process here described though in some particulars much less operose than that of Mr Keyser, yet nearly approaches to it, and furnishes us with the mildest of the saline mercurials.

**Calcined quicksilver. L.**

Take of purified quicksilver, one pound; expose the quicksilver in a flat-bottomed glass cucurbit, to an heat of about 600 degrees in a sand-bath, till it becomes a red powder.

This preparation may now be made in a shorter time than by the process formerly directed in the London pharmacopoeia, which in general required several months; for the access of air, without which calcination cannot be performed, was then very much excluded. Still, however, the process is a tedious one, and might perhaps be improved. A vessel might be contrived, as to occasion a continual flux of air over the surface of the mercury.

This preparation is highly esteemed in venereal cases, and supposed to be the most efficacious and certain of all the mercurials. It may be advantageously given in conjunction with opiates: a bolus or pill, containing from half a grain to two grains of this calx, and a quarter or half a grain or more of opium, with the addition of some warm aromatic ingredient, may be taken every night. Thus managed, it acts mildly, though powerfully, as an alternative and diaphoretic: given by itself in larger doses, as four or five grains, it proves a rough emetic and cathartic.

**Ash-coloured powder of mercury. E.**

Take of quicksilver, weak nitrous acid, equal weights. Mix them so as to dissolve the quicksilver; dilute the solution with pure water, and add spirit of salt ammoniac as much as is sufficient to separate the mercury perfectly from the acid; then wash the powder in pure water, and dry it.

In this process the mercurial nitre is decomposed; the precipitate, therefore, is a calx of mercury, and the clear liquor a solution of nitrous ammoniac. From the great attraction which the nitrous acid has for phlogiston, or from its ready disposition to part with pure air, the precipitates of mercury from its solution in this acid are more completely in the state of a calx than those from any other menstruum. There are, however, several niceties to be observed in conducting this process. If we employ too small a proportion of acid, and affix the solution by heat, the solution will contain an excess of calx capable of being separated by the water; and the whole precipitate from such a solution would be of a white colour. If, on the other hand, we employ too large a proportion of acid, the mercury is then so far calcined as to be capable of being dissolved by the volatile alkali; and this might happen in proportion as the quantity should be superabundant to the neutralization of the acid. The use of the water is to dissolve the nitrous ammoniac as fast as it is formed, and thereby prevent it from falling down and mixing with the precipitate. It is necessary to employ the purest water. If such be used as contains a nitrous selenite, not only a part of the mercury may be precipitated by the base of the selenite, but this last might also be deposited by the succeeding addition of the alkali.

The ash-coloured powder of mercury has of late years been much celebrated for the cure of venereal affections. It was first proposed by Dr Saunders to be made by precipitating the mercury from calomel, as the best substitute for the tedious and expensive process of the precipitate per se, and of the grey powder produced by trituration with gum arabic. From the testimony of Dr Home, and several other practitioners, we have no doubt of its being a very valuable preparation of mercury. It may be given in a bolus or wafer, in the quantity of from one to six or seven grains; the dose being gradually increased according to its effects upon the person. Quicksilver with chalk. L.

Take of purified quicksilver, three ounces; powdered chalk, five ounces. Rub them together until the globules disappear.

In this preparation, as well as the two former, we have also the mercury in a state of calx; but in place of being brought to that state by the aid of fire or of acids, what may here be considered as calcination is effected by trituration.

This preparation had no place in the former editions of the London pharmacopoeia. A preparation nearly similar indeed, under the title of mercurius alkalifatus, in which crabs eyes were employed instead of chalk, had a place in the old editions of the Edinburgh pharmacopoeia, but was rejected from the edition of 1744, and has never again been restored. One reason for rejecting it was its being liable to gross abuse in the preparation, by the addition of some intermediate, facilitating the union of mercury with the absorbent earth, but diminishing or altering its power. The present preparation is liable to the same objection. Some, however, are of opinion, that when duly prepared, it is an useful alternative. But there can be little doubt, that the absorbent earth, by destroying acid in the alimentary canal, will diminish the activity of the mercurial calx.

Muriated quicksilver. L.

Take of purified quicksilver, vitriolic acid, each two pounds; dried sea-salt, three pounds and an half. Mix the quicksilver with the acid in a glass vessel, and boil in a sand heat until the matter be dried. Mix it, when cold, with the sea-salt, in a glass vessel; then sublimate in a glass cucurbit, with a heat gradually raised. Lastly, let the sublimed matter be separated from the scoriae.

Sublimate corrosive mercury. E.

Take of quicksilver, weak nitrous acid, each four ounces; calcined sea-salt, calcined vitriol, of each five ounces. Dissolve the quicksilver in the nitrous acid, and evaporate the solution to a white and thoroughly dry mass: then add the sea-salt and vitriol. Having ground and mixed them well together, put the whole into a phial, one half of which they ought to fill; then sublimate in sand, first with a gentle, but afterwards with an increased, heat.

The sublimate prepared by either of these methods is the same, they both consist only of mercury and the acid of the sea-salt united together. In the process directed by the Edinburgh college, the materials being mixed and exposed to the fire, first the vitriol parts with its acid, which, dislodging those of the nitre and marine salt, takes their place. The marine acid, resolved into fume and assisted by the nitrous, dissolves the mercury, now also strongly heated. This acid, though it very difficultly acts on mercury, yet when thus once united with it, is more strongly retained thereby than any other acid. The nitrous spirit, therefore, having nothing to retain it (for its own basis and that of the sea-salt are both occupied by the vitriolic, and that which the vitriolic forsook to unite with these, is now scarcely combinable with it), arises; leaving the mercury and marine acid to sublime together when the heat shall be strong enough to elevate preparations. Some small portion of the marine spirit arises along with the nitrous; and hence this compound acid composition has been usually employed instead of the compound aquafortis, to which it is similar, for making the red corrosive.

It appears, therefore, that the vitriol, and the bases of the nitre and sea-salt, are of no farther use in this process, than as convenient intermediaries for facilitating the union of the mercury with the marine acids. They likewise serve to afford a support for the sublimate to rest upon, which thus assumes the form of a placenta or cake.

The process, however, now adopted by the London college, is a better and more simple one. There the mercury, corroded by the vitriolic acid into a white mass, is mixed with about an equal quantity of sea-salt, and set to sublime; the vitriolic acid quits the mercury to unite with the bases of the sea-salt; and the acid of the sea-salt, now set at liberty, unites with the mercury, and sublimes with it into the compound required. The discovery of this method is generally attributed to Boulduc; though it is found also in Kunckel's Laboratorium Chymicum. When the process is conducted in this way, the residuum matter is a pure Glauber's salt, and the sublimate is also free of ferruginous matter; a greater or less quantity of which is very generally carried up along with the mercury when vitriol of iron is employed. Boulduc's method has therefore the advantage in this, that the proportion of mercury in a given quantity of sublimate must be less liable to variation.

If the mercury be corroded by the nitrous acid instead of the vitriolic, the event will be the same; that acid equally quitting the mercury, and setting loose the marine; and the sublimate made by this method is the same with the foregoing; but as the quantity of fixed matter is smaller, it more difficulty affirms the form of a cake. It requires indeed some skill in the operator to give it this appearance when either process is followed. When large quantities are made, this form may be easily obtained, by placing the mats no deeper in the sand than the surface of the matter contained in it; and removing a little of the sand from the sides of the glass, as soon as the flowers begin to appear in the neck; when the heat should likewise be somewhat lowered, and not at all raised during the whole process. The sublimation is known to be completed by the edges of the crystalline cake, which will form on the surface of the caput mortuum, appearing smooth and even, and a little removed from it.

Our apothecaries rarely, and few even of the chemists, attempt the making of this preparation themselves; greatest part of what is used among us comes from Venice and Holland. This foreign sublimate has been reported to be adulterated with arsenic. Some affirm, that this dangerous fraud may be discovered by the sublimate turning black on being moistened with alkaline ley; which by others is denied. As this point seemed of some importance to be determined, sundry experiments have been made with this view, which prove the insufficiency of alkalis for discovering arsenic. Alkaline ley, poured into a solution of pure arsenic, and into a mixture of the two solutions in different proportions, produced no blackness in any: and though the pure sublimate, and the mixtures of it with arsenic, exhibited some differences in these trials, yet these differences were neither so constant nor so strongly marked, as to be laid down universally for criteria of the presence or absence of arsenic; different specimens of sublimate, known to be pure, have been found to differ considerably in this respect; probably from their holding a little more or less mercury in proportion to the acid, or from their retaining some small portion of those acids which were employed in the preparation as intermedia.

Some chemists deny the practicability of this adulteration. There is a process common in books of chemistry, wherein sublimate and arsenic being mixed together, and set to sublime, do not arise in one mass, or yield anything similar to the preparation here intended: the arsenic absorbs the acid of the sublimate, and is reduced thereby into a liquid or butyraeous consistence; while the mercury, thus freed from the acid, distills in its fluid form: if the quantity of arsenic be insufficient to decompose the whole of the sublimate, the remainder of the sublimate concretes distinctly from the arsenical butter. From whence they conclude, that arsenic and sublimate cannot be united together into a crystalline cake, the form in which this preparation is brought to us.

The above experiment is not altogether decisive; for though arsenic and sulphur do not assume the required form by the common process, it is possible they may by some other management. It will therefore be proper to point out means for the satisfaction of those who may be desirous of convincing themselves of the genuineness of this important preparation. Let some of the sublimate, powdered in a glass mortar, be well mixed with twice its weight of black flux, and a little filings or shavings of iron; put the mixture into a crucible capable of holding four or five times as much; give a gradual fire till the ebullition ceases, and then hastily increase it to a white heat. If no fumes of a garlic smell can be perceived during the process, and if the particles of iron retain their form without any of them being melted, we may be sure that the mixture contained no arsenic.

Sublimate is a most violent corrosive, soon corrupting and destroying all the parts of the body it touches. A solution of it in water, in the proportion of about a dram to a quart, is used for keeping down proud flesh, and cleansing foul ulcers; and a more dilute solution as a cosmetic, and for destroying cutaneous insects. But a great deal of caution is requisite even in these external uses of it.

Some have nevertheless ventured to give it internally, in the dose of one-tenth or one-eighth of a grain. Boerhaave relates, that if a grain of it be dissolved in an ounce or more of water, and a dram of this solution, sweetened with syrup of violets, be taken twice or thrice a day, it will prove efficacious in many difficult cases thought incurable; but he particularly cautions us not to venture upon it, unless the method of managing it be well known.

Sublimate dissolved in vinous spirit has of late been given internally in larger doses; from a quarter of a grain to half a grain. This method of using it was brought into repute by Baron Van Swieten at Vienna, especially for venereal maladies; and several trials of it have also been made in this kingdom with success. Preparations and Compositions.

Eight grains of the sublimate are dissolved in sixteen ounces of rectified spirit of wine or proof-spirit; the rectified spirit dissolves it more perfectly, and seems to make the medicine milder in its operation than the proof-spirit of the original prescription of Van Swieten. Of this solution, from one to two spoonsfuls, that is, from half an ounce to an ounce, are given twice a day, and continued till all the symptoms are removed; observing to use a low diet, with plentiful dilution, otherwise the sublimate is apt to purge, and gripe severely. It generally purges more or less at the beginning, but afterwards seems to operate chiefly by urine and perspiration.

Sublimate consists of mercury united with a large quantity of marine acid. There are two general methods of destroying its corrosive quality, and rendering it mild; the one is, combining with it as much fresh mercury as the acid is capable of taking up; and the other, by separating a part of the acid by means of alkaline salts and earths. On the first principle sweet mercury is formed; on the latter, white precipitate. But before entering on these, it is proper to give the following formula.

Solution of corrosive sublimate mercury. E.

Take of corrosive sublimate mercury, six grains; sal ammoniac, twelve grains. Dissolve in a pound of distilled water. If hard water be used for this purpose, the solution suffers a kind of decomposition from the nitrous selenite of the water.

The solution of corrosive sublimate in water is very much assisted by sal ammoniac. There was a practice some years ago, of mixing up this solution with wheat flour into the consistence of pills for internal use; and the quantity of sublimate in each pill was easily ascertained.

This solution may also be used for washing venereal and other sores; but in many instances it will be found too acid for that purpose, and will require to be weakened by the addition of a portion of water.

Calomel. L.

Take of muriated quicksilver, one pound; purified quicksilver, nine ounces. Rub them together till the globules disappear, and then sublime the mass. In the same manner repeat the sublimation four times. Afterwards rub the matter into a very fine powder, and wash it by pouring on boiling distilled water.

Sweet mercury. E.

Take of corrosive mercury sublimate, reduced to a powder in a glass mortar, four ounces; pure quicksilver, three ounces and a half. Mix them well together, by long trituration in a glass or marble mortar, until the quicksilver ceases to appear. Put the powder into an oblong phial, of such a size that only one-third of it may be filled; and set the glass in sand, that the mass may sublime. After the sublimation, break the glass; and the red powder which is found in its bottom, with the whitish one that sticks about the neck, being thrown away, let the white mercury be sublimed again three or four times, and reduced to a very fine powder. The trituration of corrosive sublimate with quicksilver is a very noxious operation: for it is almost impossible, by any care, to prevent the lighter particles of the former from rising so as to affect the operator's eyes and mouth. It is nevertheless of the utmost consequence, that the ingredients be perfectly united before the sublimation is begun. It is necessary to pulverize the sublimate before the mercury is added to it; but this may be safely performed with a little caution; especially if during the pulverization the matter be now and then sprinkled with a little spirit of wine: this addition does not at all impede the union of the ingredients, or prejudice the sublimation: it will be convenient not to close the top of the subliming vessel with a cap of paper at first (as is usually practiced), but to defer this till the mixture begins to sublime, that the spirit may escape.

The rationale of this process deserves particular attention; and the more so, as a mistaken theory herein has been productive of several errors with regard to the operation of mercurials in general. It is supposed, that the dulcification, as it is called, of the corrosive mercury is owing to the spiculae or sharp points, on which its corrosiveness depends, being broken and worn off by the frequent sublimations. If this opinion were just, the corrosive would become mild, without any addition, barely by repeating the sublimation; but this is contrary to all experience. The abatement of the corrosive quality of the sublimate is entirely owing to the combination of as much fresh mercury as is capable of being united with it; and by whatever means this combination be effected, the preparation will be sufficiently dulcified. Triture and digestion promote the union of the two, while sublimation tends rather to disunite them. The prudent operator, therefore, will not be solicitous about separating such mercurial globules as appear distinct after the first sublimation: he will endeavour rather to combine them with the rest, by repeating the triture and digestion.

The college of Wurtemberg require their sweet mercury to be only twice sublimed, and the Augustan but once; and Neumann proposes making it directly by a single sublimation from the ingredients of the corrosive sublimate, by only taking the quicksilver in a larger proportion.

Mr Selle of Berlin has lately proposed a method of making sweet mercury nearly similar to that of Neumann. He directs, that to four ounces of pure quicksilver there should be added as much strong vitriolic acid. These are to be mixed over a strong fire till they become a solid hard mass. This mass is to be triturated in a stone mortar with two ounces and an half of quicksilver and four ounces and an half of dried common salt. And by a single, or at most two, sublimations, he affirms us an excellent sweet mercury is obtained.

If the medicine made after either of these methods should prove in any degree acid, water boiled on it for some time will dissolve and separate that part in which its acrimony consists. The marks of the preparation being sufficiently dulcified are, its being perfectly insipid to the taste, and indissoluble by long boiling in water. Whether the water in which it has been boiled has taken up any part of it, may be known by dropping into the liquor a ley of any fixed alkaline salt, or any volatile alkaline spirit. If the decoction has any mercurial impregnation, it will grow turbid on this addition; if otherwise, it will continue limpid.

But here care must be taken not to be deceived by any extraneous saline matter in the water itself. Most of the common spring waters turn milky on the addition of alkalis; and therefore, for experiments of this kind, distilled water or rain water ought to be used.

This name of calomel, though for a considerable time banished from our best pharmacopoeias, is again restored by the London college. But we cannot help thinking, that they might easily have invented a name better expressing the constituent parts and nature of the preparation.

Calomel, or sweet mercury, may be considered as one of the most useful of the mercurial preparations; and it may be estimated as holding an intermediate place between the acetated quicksilver, one of the mildest of the saline preparations, and the muriated quicksilver, or corrosive sublimate, one of the most acid of them.

**Mild muriated quicksilver.**

Take purified quicksilver, diluted nitrous acid, of each half a pound. Mix in a glass vessel, and set it aside until the quicksilver be dissolved. Let them boil, that the salt may be dissolved. Pour out the boiling liquor into a glass vessel into which another boiling liquor has been put before, consisting of sea-salt, four ounces; distilled water, eight pints. After a white powder has subsided to the bottom of the vessel, let the liquor swimming at the top be poured off, and the remaining powder be washed till it becomes insipid, with frequent affusions of hot water; then dried on blotting paper with a gentle heat.

This preparation had a place in former editions of the London and Edinburgh pharmacopoeias under the name of mercurius dulcis precipitatus. But the process as now given is somewhat altered, being that of Mr Scheele of Sweden, who has recommended this as an easy and expeditious method of preparing sweet mercury or calomel.

It appears from several tests that this precipitate is equal in every respect to that prepared by the preceding processes. It is less troublesome and expensive, and the operator is not exposed to the noxious dust arising from the triture of the quicksilver with the corrosive sublimate, which necessarily happens by the common method. The powder is also finer than can be made from the common sublimed sweet mercury by any trituration whatever. The clear liquor standing over the precipitate is a solution of cubic or rhomboidal nitre.

Sweet mercury, which may be considered as precisely the same with the calomel and mild muriated quicksilver, appears to be one of the best and safest preparations of this mineral, when intended to act as a quick and general stimulant. Many of the more elaborate processes are no other than attempts to produce from mercury such a medicine as this really is. The dose, recommended by some for raising a salivation, is ten or fifteen grains taken in the form of a bolus or pill, every night or oftener, till the ptyalism begins. As an alterant and diaphoretic, it has been given in doses of five or six grains; a purgative being occasionally fionally interposed, to prevent its affecting the mouth. It answers, however, much better when given in smaller quantities, as one, two, or three grains every morning and evening, in conjunction with such substances as determine its action to the skin, as the extract or resin of guaiacum; the patient at the same time keeping warm, and drinking liberally of warm diluent liquors. By this method of managing it, obstinate cutaneous and venereal distempers have been successfully cured without any remarkable increase of the sensible evacuations. It is sometimes, however, difficult to measure its effects in this way; and it is so very apt to run off by the intestines, that we can seldom administer it in such a manner as to produce those permanent effects which are often required, and which we are able to do by other preparations. It has been lately proposed to rub the gums and inside of the mouth with this preparation, as a ready and effectual method of producing salivation. This practice has been particularly recommended in the internal hydrocephalus, where it is exceedingly difficult to excite a salivation by other means. The advantages of this practice are not fully confirmed by experience; and when mercury is attended with advantage in hydrocephalus, this is not probably the consequence of any discharge under the form of salivation, but merely of the mercury being introduced into the system in an active state, and thus promoting absorption. And salivation, when it arises from the internal use of mercury, may be considered as the strongest test of this; but this is by no means the case when salivation arises from a topical action on the excretories of saliva.

Red nitrated quicksilver. L.

Take of purified quicksilver, nitrous acid, each one pound; muriatic acid, one dram. Mix in a glass vessel, and dissolve the quicksilver in a sand bath; then raise the fire until the matter be formed into red crystals.

Red corrosive, commonly called red precipitated mercury. E.

Take of quicksilver, weak nitrous acid, each one pound. Let the quicksilver be dissolved in the acid, and then let the solution be evaporated to a white dry mass. This being beat into a powder, must be put into a glass retort, and subjected to a fire gradually increased, till a small quantity of it, taken out in a glass spoon, and allowed to cool, assumes the form of shining red squamae. Let the vessel be then removed from the fire. During the process the matter must be carefully agitated by a glass rod, that it may be equally heated.

The marine acid, in the menstruum ordered in the first process, disposes the mercurial calx to assume the bright sparkling look admired in it; which, though perhaps no advantage to it as a medicine, ought nevertheless to be insisted on by the buyer as a mark of its goodness and strength. As soon as the matter has gained this appearance, it should be immediately removed from the fire, otherwise it will soon lose it again. The preparation of this red precipitate, as it is called, in perfection, is supposed by some to be a secret not known to our chemists, insomuch that we are under the necessity of importing it from abroad. This reflection seems to be founded on misinformation.

We sometimes indeed receive considerable quantities of it from Holland; but this depends on the ingredients and compositions being commonly cheaper there than with us, and not on any secret in the manner of the preparation.

This precipitate is, as its title imports, an escharotic; and with this intention is frequently employed by the surgeons with basilicum and other dressings, for consuming fungous flesh in ulcers and the like purposes. It is subject to great uncertainty in point of strength, more or less of the acid exhaling according to the degree and continuance of the fire. The best criterion of its strength, as already observed, is its brilliant appearance; which is also the mark of its genuineness: if mixed with minium, which it is sometimes said to be, the duller hue will discover the abuse. This admixture may be more certainly detected by means of fire: the mercurial part will totally evaporate, leaving the minium behind.

Some have ventured to give this medicine internally in venereal, scorfulous, and other obstinate chronic disorders, in doses of two or three grains or more. But certainly the milder mercurials, properly managed, are capable of answering all that can be expected from this; without occasioning violent anxieties, torments of the bowels, and similar ill consequences, which the best management can scarcely prevent this corrosive preparation from sometimes inducing. The chemists have contrived sundry methods of correcting and rendering it milder, by diverting it of a portion of the acid; but to no very good purpose, as they either leave the medicine still too corrosive, or render it similar to others which are procurable at an easier rate.

White calx of quicksilver. L.

Take of muriated quicksilver, sal ammoniac, water of kali, each half a pound. Dissolve first the sal ammoniac, afterwards the muriatic quicksilver, in distilled water, and add the water of kali. Wash the precipitated powder until it becomes infusible.

White precipitate of mercury. E.

Dissolve corrosive sublimate mercury in a sufficient quantity of hot water, and gradually drop into the solution some spirit of sal ammoniac as long as any precipitation ensues. Wash the precipitated powder with several fresh quantities of warm water.

These preparations are used chiefly in ointments; with which intention their fine white colour is no small recommendation to them. For internal purposes they are rarely employed, nor is it at all wanted: they are nearly similar to sweet mercury, but less certain in their effects.

Though the processes directed by the London and Edinburgh colleges be here somewhat different, yet the preparations are ultimately the same. The process described by the Edinburgh college is the most simple; but is liable to some objections.

Corrosive sublimate, as we have already seen, consists of mercury united with a large portion of acid. It is there dulcified by adding as much fresh mercury as is sufficient to saturate all the acid; here, by separating all the acid that is not saturated. This last way seems an unfrugal one, on account not only of the loss of the acid, but of the volatile spirit necessary for absorbing it. The operator may, however, if it should be thought thought worth while, recover the volatile salt from the liquor, by adding to it, after the precipitate has been separated, a proper quantity of potash, and distilling with a gentle heat, in the same manner as for the spirit or volatile salt of sal ammoniac; for a true sal ammoniac is regenerated, in the precipitation, from the union of the volatile spirit with the marine acid of the sublimate. It is by no means advisable to use the liquor itself as a solution of sal ammoniac, or to separate the sal ammoniac from it by evaporation and crystallization, as a part of the mercury might be retained, and communicate dangerous qualities; but the volatile salt separated by distillation may be used without fear of its containing any mercury; none of which will arise with the heat by which the volatile salts are distilled.

Fixed alkalis answer as effectually for precipitating solutions of sublimate as the volatile; but the precipitate obtained by means of the former, instead of being white, as with the latter, is generally of a reddish yellow or orange colour. If sal ammoniac be dissolved along with the sublimate, the addition of fixed alkalis will, by extricating the volatile alkali of the sal ammoniac, occasion as white a precipitation as if the volatile salt had been previously separated and employed in its pure state; and this compendium is now allowed by the London college in the process which they have adopted.

There the sal ammoniac, besides its use in the capital intention, to make a white precipitation, promotes the solution of the sublimate; which of itself is difficultly, and scarcely at all totally, soluble by repeated boiling in water: for however skillfully it be prepared, some part of it will have an under-proportion of acid, and consequently approach to the state of sweet mercury. A good deal of care is requisite in the precipitation; for if too large a quantity of the fixed alkaline solution be imprudently added, the precipitate will lose the elegant white colour for which it is valued.

Quicksilver with sulphur. L.

Take of purified quicksilver, flowers of sulphur, each one pound. Rub them together until the globules disappear.

Ethiops mineral. E.

Take of quicksilver, flowers of sulphur, each equal weights. Grind them together in a glass or stone mortar, with a glass pestle, till the mercurial globules totally disappear.

An ethiops is made also with a double quantity of mercury.

We need hardly remark, that these preparations, though now differing in name, are in reality the same. Nor need we add, that the direction given by the Edinburgh college, of using a glass or stone mortar and pestle, is necessary and proper.

The union of the mercury and sulphur might be much facilitated by the assistance of a little warmth. Some are accustomed to make this preparation in a very expeditious manner, by melting the sulphur in an iron ladle, then adding the quicksilver, and stirring them together till the mixture be completed. The small degree of heat here sufficient cannot reasonably be supposed to do any injury to substances which have already undergone much greater fires, not only in the preparation from their ores, but likewise in the purifications and extractions directed in the pharmacopoeia. In the following process they are exposed in conjunction to a strong fire, without suspicion of the compound receiving any ill quality from it. This much is certain, that the ingredients are more perfectly united by heat than by the degree of trituration usually bestowed on them. From the ethiops prepared by trituration, part of the mercury is apt to be squeezed out on making it into an electuary or pills; from that made by fire no separation is observed to happen.

Ethiops mineral is one of the most inactive of the mercurial preparations. Some practitioners, however, have represented it as possessing extraordinary virtues; and most people imagine it a medicine of some efficacy. But what benefit is to be expected from it in the common doses of eight or ten grains, or a scruple, may be judged from hence, that it has been taken in doses of several drams, and continued for a considerable time, without producing any remarkable effect. Sulphur eminently abates the power of all the more active minerals, and seems to be at the same time restrained by them from operating in the body itself. Boerhaave, who is in general sufficiently liberal in the commendation of medicines, disapproves of the ethiops in very strong terms. "It cannot enter the absorbent vessels, the lacteals, or lymphatics, but passes directly through the intestinal tube, where it may happen to destroy worms, if it operates luckily. They are deceived who expect any other effects from it; at least I myself could never find them. I am afraid it is unwarily given, in such large quantities, to children and persons of tender constitutions, as being a foreign mass, unconquerable by the body; the more to be suspected as it there continues long sluggish and inactive. It does not raise a salivation, because it cannot come into the blood. Who knows the effects of a substance, which, so long as it remains compounded, seems no more active than any ponderous infipid earth?" The ethiops, with a double proportion of mercury, now received into our pharmacopoeia, has a greater chance for operating as a mercurial; and probably the quantity of mercury might be still further increased to advantage.

Red sulphurated quicksilver. L.

Take of quicksilver, purified, forty ounces; sulphur, eight ounces. Mix the quicksilver with the melted sulphur; and if the mixture takes fire, extinguish it by covering the vessel; afterwards reduce the mass to powder, and sublime it.

It has been customary to order a larger quantity of sulphur than here directed; but smaller proportions answer better, for the less sulphur the finer coloured is the cinnamon.

As soon as the mercury and sulphur begin to unite, a considerable explosion frequently happens, and the mixture is very apt to take fire, especially if the process be somewhat hastily conducted. This accident the operator will have previous notice of, from the matter swelling up, and growing suddenly consistent; as soon as this happens, the vessel must be immediately close covered.

During the sublimation, care must be had that the matter matter rise not into the neck of the vessel, so as to block up and burst the glass. To prevent this, a wide-necked bottle head, or rather an oval earthen jar, coated, should be chosen for the subliming vessel. If the former be employed, it will be convenient to introduce at times an iron wire, somewhat heated, in order to be the better assured that the passage is not blocking up; the danger of which may be prevented by cautiously raising the vessel higher from the fire.

If the ingredients were pure, no feces will remain: in such cases, the sublimation may be known to be over by introducing a wire as before, and feeling there-with the bottom of the vessel, which will then be perfectly smooth: if any roughnesses or inequalities are perceived, either the mixture was impure, or the subli-mation is not completed: if the latter be the case, the wire will soon be covered over with the rising cinnabar.

The preparers of cinnabar in large quantity employ earthen jars, which in shape pretty much resemble an egg. These are of different sizes, according to the quantity intended to be made at one sublimation, which sometimes amounts to two hundred weight. The jar is usually coated from the small end almost to the middle, to prevent its breaking by the vehemence or irregularity of the fire. The greater part, which is placed uppermost, not being received within the furnace, has no occasion for this defence. The whole secret with regard to this process, is the management of the fire, which should be so strong as to keep the matter continually subliming to the upper part of the jar, without coming out at its mouth, which is covered with an iron plate; care should also be taken to put into the subliming vessel only small quantities of the mixture at a time.

The principal use of cinnabar is as a pigment. It was formerly held in great esteem as a medicine in cutaneous foulnesses, gouty and rheumatic pains, epileptic cases, &c. but of late it has lost much of its reputation. It appears to be nearly similar to the antipodes already spoken of. Cartheuer relates, that having given cinnabar in large quantities to a dog, it produced no sensible effect, but was partly voided along with the feces unaltered, and partly found entire in the stomach and intestines on opening the animal. The celebrated Frederic Hoffman, after bestowing high encomiums on this preparation, as having in many instances within his own knowledge perfectly cured epilepsy and vertigo from contusions of the head (where it is probable, however, that the cure did not so much depend on the cinnabar as on the spontaneous recovery of the parts from the external injury), observes, that the large repeated doses, necessary for having any effect, can be borne only where the first passages are strong; and that if the fibres of the stomach and intestines are lax and flaccid, the cinnabar, accumulated and concreting with the mucous matter of the parts, occasions great oppression; which seems to be an acknowledgment that the cinnabar is not subdued by the powers of digestion, and has no proper medicinal activity. There are indeed some instances of the daily use of cinnabar having brought on a salivation; perhaps from the cinnabar, used in those cases, having contained a less proportion of sulphur than the sorts commonly met with. The regulus of antimony, and even white arsenic, when combined with a certain quantity of common sulphur, seem to have their deleterious power destroyed: on separating more and more of the sulphur, they exert more and more of their proper virulence. It does not seem unreasonable to presume, that mercury may have its activity varied in the same manner; that when perfectly satiated with sulphur, it may be inert; and that when the quantity of sulphur is more, and more lessened, the compound may have greater and greater degrees of the proper efficacy of mercurials.

Cinnabar is sometimes used in fumigations against venereal ulcers in the nose, mouth, and throat. Half a dram of it burnt, the fume being imbibed with the breath, has occasioned a violent salivation. This effect is by no means owing to the medicine as cinnabar: when set on fire, it is no longer a mixture of mercury and sulphur, but mercury resolved into fume, and blended in part with the volatile vitriolic acids; in either of which circumstances this mineral, as we have already observed, has very powerful effects.

**Vitriolated quicksilver.**

Take of quicksilver, purified, vitriolic acid, each one pound. Mix in a glass vessel, and heat them by degrees until they unite into a white mass, which is to be perfectly dried with a strong fire. This matter, on the addition of a large quantity of hot distilled water, immediately becomes yellow, and falls to powder. Rub the powder carefully with this water in a glass mortar. After the powder has subsided, pour off the water; and, adding more distilled water several times, wash the matter till it become insipid.

**Yellow mercury, commonly called Turpith mineral.**

Take of quicksilver, four ounces; vitriolic acid, eight ounces. Cautiously mix them together, and distil in a retort, placed in a sand furnace, to dryness: the white calx, which is left at the bottom, being ground to powder, must be thrown into warm water. It immediately afflames a yellow colour, but must afterwards be purified by repeated ablutions. The quantity of oil of vitriol, formerly directed, was double to that now employed by the Edinburgh college. The reduction made in this article greatly facilitates the process; and the proportions of the London college are perhaps preferable.

Boerhaave directs this preparation to be made in an open glass, slowly heated, and then placed immediately on burning coals; care being taken to avoid the fumes, which are extremely noxious. This method will succeed very well with a little address when the ingredients are in small quantity; but where the mixture is large, it is better to use a retort, placed in a sand-furnace, with a recipient containing a small quantity of water, luted to it. Great care should be taken, when the oil of vitriol begins to bubble, that the heat be steadily kept up, without at all increasing it, till the ebullition ceases, when the fire should be augmented to the utmost degree, that as much as possible of the redundant acid may be expelled.

If the matter be but barely exsiccated, it proves a caustic salt, which in the allusion with water will almost all dissolve, leaving only a little quantity of turpith; bith: the more of the acid that has been diffipated, the less of the remaining mercury will dissolve, and consequently the yield of turbith will be greater; fire expelling only such part of the acid as is not completely satiated with mercury, while water takes up always, along with the acid, a proportional quantity of the mercury itself. Even when the matter has been strongly calcined, a part will still be soluble; this evidently appears on pouring into the washings a little solution of fixed alkaline salt, which will throw down a considerable quantity of yellow precipitate, greatly resembling the turbith, except that it is less violent in operation.

From this experiment it appears, that the best method of edulcorating this powder is, by impregnating the water, intended to be used in its ablution, with a determined proportion of fixed alkaline salt; for by this means, the washed turbith will not only turn out greater in quantity, but, what is of more consequence, will have an equal degree of strength; a circumstance which deserves particularly to be considered, especially in making such preparations as, from an error in the process, may prove too violently corrosive to be used with any tolerable degree of safety. It is necessary to employ warm water if we are anxious for a fine colour. If cold water be used, the precipitate will be white.

It is observable, that though the superfluous acid be here absorbed from the mercury by the alkaline salt; yet in some circumstances this acid forfeits that salt to unite with mercury. If vitriolated tartar, or vitriolated kali, as it is now called, which is a combination of vitriolic acid with fixed alkali, be dissolved in water, and the solution added to a solution of mercury in aquafortis, the vitriolic acid will unite with the mercury, and form with it a turbith, which falls to the bottom; leaving only the alkali dissolved in the aquafortis, and united with its acid into a regenerated nitre. On this principle depends the preparation described by Wilson under the title of an excellent precipitate of mercury; which is no other than a true turbith, though not generally known to be such. It is made by dissolving four ounces of vitriolated kali in sixteen ounces of spirit of nitre; dissolving in this compound liquor four ounces of mercury; abstracting the menstruum by a sand heat; and edulcorating with water the gold-coloured mass which remains.

Turbith mineral is a strong emetic, and with this intention operates the most powerfully of all the mercurials that can be safely given internally. Its action, however, is not confined to the prime vice; it will sometimes excite a salivation, if a purgative be not taken soon after it. This medicine is used chiefly in virulent gonorrhoeas, and other venereal cases, where there is a great flux of humours to the parts. Its chief use at present is in swellings of the testicle from a venereal affection; and it seems not only to act as a mercurial, but also, by the fever vomiting it occasions, to perform the office of a disfectient, by accelerating the motion of the blood in the parts affected. It is said likewise to have been employed with success, in robust constitutions, against leprous disorders and obstinate glandular obstructions: the dose is from two grains to six or eight. It may be given in doses of a grain or two as an alternative and diaphoretic, in the same manner as the calcined mercury already spoken of. Dr Hope has found that the turbith mineral is the most convenient errhine he has had occasion to employ.

This medicine was lately recommended as the most effectual preservative against the hydrophobia. It has been alleged there are several examples of its preventing madness in dogs which had been bitten; and some of its performing a cure after the madness was begun: from six or seven grains to a scruple may be given every day, or every second day, for a little time, and repeated at the two or three succeeding fulls and changes of the moon. Some few trials have likewise been made on human subjects bitten by mad dogs; and in these also the turbith, used either as an emetic or alterative, seemed to have good effects.

The washings of turbith mineral are used by some externally for the cure of the itch and other cutaneous foulnesses. In some cases mercurial lotions may be proper, but they are always to be used with great caution: this is by no means an eligible one, as being extremely unequal in point of strength, more or less of the mercury being dissolved, as has been observed above, according to the degree of calcination. The pharmacopoeia of Paris directs a mercurial wash free from this inconvenience, under the title of Aqua mercurialis, or Mercurius liquidus. It is composed of one ounce of mercury, dissolved in a sufficient quantity of spirit of nitre, and diluted with thirty ounces of distilled water. In want of distilled water, rain water may be used; but of spring waters there are very few which will mix with the mercurial solution without growing turbid and precipitating a part of the mercury.

Simple mercurial solution. Jof. Jac. Plenck.

Take of purest quicksilver, one dram; gum arabic, two drams. Beat them in a stone mortar, adding by little and little distilled water of fumitory till the mercury thoroughly disappear in the mucilage. Having beat and mixed them thoroughly, add by degrees, and at the same time rubbing the whole together, syrup of kermes, half an ounce, distilled water of fumitory, eight ounces.

This mixture was much celebrated by its author as an effectual preparation of mercury, unattended with the inconvenience of producing a salivation; and he imagined that this depended on a peculiar affinity existing between mercury and mucilage. Hence such a conjunction, the gummy quicksilver, as it has been styled, has been the foundation of mixtures, pills, syrups, and several other formulae, which it is unnecessary to dwell upon in this place.

By a long continued trituration, mercury seems to undergo a degree of calcination; at least its globular appearance is not to be discerned by the best microscope; its colour is converted into that of a greyish powder; and from the inactive substance in its globular form, it is now become one of the most powerful preparations of this metallic body. The use of the gum seems to be nothing more than to afford the interposition of a viscid substance to keep the particles at a distance from each other, till the trituration requisite to produce this change be performed. Dr Saunders has clearly proved, that no real solution takes place in this this process, and that though a quantity of mercurial particles are still retained in the mixture after the globular parts have been deposited by dilution with water, yet that this suspended mercurial matter is only diffused in the liquor, and capable of being perfectly separated by filtration. That long trituration is capable of effecting the above change on mercury, is fully evinced from the well-known experiment of Dr. Boerhaave, in producing a kind of calcined mercury by exposing quicksilver inclosed in a phial to the agitation produced by keeping the phial tied to a windmill for 14 years. By including a pound of quicksilver in an iron box, with a quantity of iron nails and a small quantity of water, by the addition of which a greater degree of intestine motion is given to the particles of the mercury, and fixing the box to the wheel of a carriage, Dr. Saunders obtained, during a journey of 450 miles, two ounces of a greyish powder, or calx of mercury.

On the above accounts we are not to ascribe the effects of Plenck's solution to an intimate division of the globules of mercury, nor to any affinity, nor elective attraction, between gum-arabic and mercury; which last Mr. Plenck has very unphilosophically supposed. The same thing can be done by means of gum-tragacanth, by honey, and by sundry balsams. It is evidently owing to the conversion of the quicksilver to a calciform nature; but as this will be accomplished more or less completely according to the different circumstances during the trituration, it is certainly preferable, instead of Plenck's solution, to diffuse in mucilage, or other viscid matters, a determinate quantity of the ash-colored powder, or other calx of mercury.

It is proper to take notice, that there is in many instances a real advantage in employing mucilaginous matters along with mercurials, these being found to prevent diarrhoea and salivation to a remarkable degree. So far, then, Mr. Plenck's solution is a good preparation of mercury, though his chemical rationale is perhaps erroneous. The distilled water and syrup are of no consequence to the preparation, either as facilitating the process, or for medicinal use.

It is always most expeditious to triturate the mercury with the gum in the state of mucilage. Dr. Saunders found that the addition of honey was an excellent auxiliary; and the mucilage of gum-tragacanth seems better suited for this purpose than gum-arabic.

**CHAP. XIV. Preparations of Lead.**

Lead readily melts in the fire, and calcines into a dusty powder; which, if the flame is reverberated on it, becomes at first yellow, then red, and at length melts in a vitreous mass. This metal dissolves easily in the nitrous acid, difficultly in the vitriolic, and in small quantity in the vegetable acids; it is also soluble in expressed oil, especially when calcined.

Lead and its calces, while undissolved, have no considerable effects as medicines. Dissolved in oils, they are supposed to be (when externally applied) anti-inflammatory and deificative. Combined with vegetable acids, they are remarkably so; and, taken internally, prove a powerful though dangerous styptic.

There are two preparations of lead, red and white. Red lead, as they are commonly called, which are much more extensively employed in other arts than in medicine, and, of course, they are prepared in large quantities. These formerly stood among the preparations in our pharmacopoeias; but they are now referred to the materia medica. We shall not therefore, on the present occasion, make any farther observations with respect to them, but shall here insert from the old editions of the Edinburgh pharmacopoeia the directions there given for preparing them.

**Red lead.**

Let any quantity of lead be melted in an unglazed earthen vessel, and kept stirring with an iron spatula till it falls into powder, at first blackish, afterwards yellow, and at length of a deep red colour, in which last state it is called minium; taking care not to raise the fire so high as to run the calx into a vitreous mass.

The preparation of red lead is so troublesome and tedious, as scarce ever to be attempted by the apothecary or chemist; nor indeed is this commodity expected to be made by them, the preparation of it being a distinct branch of business. The makers melt large quantities of lead at once, upon the bottom of a reverberatory furnace built for this purpose, and so contrived that the flame acts on a large surface of the metal, which is continually changed by means of iron rakes drawn backwards and forwards, till the fluidity of the lead is destroyed; after which, the calx is only now and then turned. By barely stirring the calx, as above directed, in a vessel over the fire, it acquires no redness; the reverberation of flame on the surface being absolutely necessary for this effect. It is said, that 20 pounds of lead gain, in this process, five pounds; and that the calx, being reduced into lead again, is found one pound less than the original weight of the metal.

These calces are employed in external applications, for abating inflammations, cleansing and healing ulcers, and the like. Their effects, however, are not very considerable; nor are they perhaps of much farther real use, than as they give confidence to the plaster, unguent, &c.

**Ceruse or white lead.**

Put some vinegar into the bottom of an earthen vessel, and suspend over the vinegar very thin plates of lead, in such a manner that the vapour which arises from the acid may circulate about the plates. Set the containing vessel in the heat of horse-dung for three weeks; if at the end of this time the plates be not totally calcined, scrape off the white powder, and expose them again to the steam of vinegar, till all the lead be thus corroded into powder.

The making of white lead is also become a trade by itself, and confined to a few persons, who have large conveniences for this purpose. The general method which they follow is nearly the same with that above described. See the Philosophical Transactions, no. 137.

In this preparation, the lead is so far opened by the acid, as to discover, when taken internally, the malignant quality of the metal; and to prove externally, when sprinkled on running sores, or ulcers, moderately cooling, drying, and astringent.

**Acetated ceruse.** L.

Take of ceruse, one pound; distilled vinegar, one gallon and an half. Boil the ceruse with the vinegar until the vinegar is saturated; then filter through paper; and, after proper evaporation, set it aside to crystallize.

**Salt,** commonly called sugar of lead. E.

Put any quantity of ceruse into a cucurbit, and pour upon it ten times its quantity of distilled vinegar. Let the mixture stand upon warm sand till the vinegar becomes sweet; when it is to be poured off, and fresh vinegar added as often as it comes off sweet. Then let all the vinegar be evaporated in a glass vessel to the consistence of pretty thin honey, and let it aside in a cold place, that crystals may be formed, which are to be afterwards dried in the shade. The remaining liquor is again to be evaporated, that new crystals may be formed; the evaporation of the residuous liquor is to be repeated till no more crystals concrete.

Ceruse (especially that sort called flake lead, which is not, like the others, subject to adulteration) is much preferable either to minium or litharge, for making the sugar of lead: for the corrosion which it has undergone from the steam of the vinegar disposes it to dissolve more readily. It should be finely powdered before the vinegar be put to it; and during the digestion, or boiling, every now and then stirred up with a wooden spatula, to promote its dissolution, and prevent its concreting into a hard mass at the bottom. The strong acid obtained from the caput mortuum of vinegar may be employed for this purpose to better advantage than the weaker, though purer acid, above directed. If a small quantity of rectified spirit of wine be prudently added to the solution as soon as it is duly exhaled, and the mixture suffered to grow cold by slow degrees, the sugar will concrete into very large and transparent crystals, which are scarcely to be obtained by any other method.

If the crystals be dried in sunshine, they acquire a blackish or livid colour. This seems to happen from the absorption of light and its conversion into phlogiston. If it be owing to the escape of pure air, why are the rays of the sun necessary to this discharge? On whatever principles we account for it, the fact is the same; that the crystals soon lose their saline condition, and the lead gradually reassumes its metallic form. From this property of lead readily absorbing phlogiston, or parting with pure air, a solution of the sugar of lead becomes a very convenient sympathetic ink; on the same grounds it is also used for a more important purpose. As lead communicates a sweetness and astringency very similar to the product of the vinous fermentation, a practice formerly prevailed among fraudulent dealers, of correcting the too great sharpness of acid wines by adulterating them with this metal. The abuse may be detected in two different ways: a piece of paper may be moistened with the liquor to be examined, and then exposed to the vapours of liver of sulphur; the moistened paper will become of a livid colour, and this will happen though 200 or 300 leaves of a book were interposed between the paper and the vapours; by this method, then, we make a kind of sympathetic ink. But the best way of making the test is, to drop a small quantity of a solution of the liver of sulphur into the suspected liquor: if there be any lead present, this addition will instantly occasion the precipitation of a livid or dark coloured cloud.

The sugar of lead is much more efficacious than the foregoing preparations, in answering the several intentions to which they are applied. Some have ventured upon it internally, in doses of a few grains, as a styptic in haemorrhages, profuse colliquative fevers, seminal fluxes, the fluor albus, &c. nor has it failed their expectations. It very powerfully restrains the discharge; but almost as certainly as it does this, it occasions symptoms of another kind, often more dangerous than those removed by it, and sometimes fatal. Violent pains in the bowels or through the whole body, and obstinate constipations, sometimes immediately follow, especially if the dose has been considerable: cramps, tremors, and weakness of the nerves, generally sooner or later ensue.

Boerhaave is of opinion, that this preparation proves malignant only as far as its acid happens to be absorbed in the body; for in such case, he says, "it returns again into ceruse, which is violently poisonous." On this principle it would follow, that in habits where acidities abound, the sugar of lead would be innocent. But this is far from being the case. Lead and its preparations act in the body only when they are combined with acid; ceruse possesses the qualities of the saccharum only in a low degree; and either of them freed from the acid has little, if any, effect at all. For the same reasons, the salt of lead is preferable to the pompous extract and vegeto-mineral water of Gouland, in which the lead is much less perfectly combined in a saline state. It is sometimes convenient to assist the solution of the sugar of lead in water, by adding a portion of vinegar. The effects of the external application of lead seems to differ from the strength of the solution: thus a very weak solution seems to diminish directly the action of the vessels, and is therefore more peculiarly proper in active inflammations, as of the eyes; whereas a strong solution operates as a direct stimulant, and is therefore more successful in palliative ophthalmia.

**Water of acetated litharge.** L.

Take of litharge, two pounds and four ounces; distilled vinegar, one gallon. Mix, and boil to six pints, constantly stirring; then set it aside. After the feces have subsided, strain.

This preparation may be considered as nearly the same with the extract and vegeto-mineral water of Mr Gouland. And it is probably from the circumstances of his preparations having come into a common use, that the London college have given this article a place in their pharmacopoeia. It may, however, be a matter of doubt whether it be really entitled to a place. For, as we have already observed, every purpose to be answered by it may be better obtained from the employment Part II.

Chap. XV. Preparations of tin.

Tin easily melts in the fire, and calcines into a dusty powder; which, by a farther continuance of the heat, becomes white. A mass of tin heated till it be just ready to melt, proves extremely brittle, so as to fall in pieces from a blow; and by dexterous agitation, into powder. Its proper menstruum is aqua-regia; though the other mineral acids may also be made to dissolve it, and the vegetable ones in small quantity. It crystallizes with the vegetable and vitriolic acids; but with the others, deliquesces.

The virtues of this metal are little known. It has been recommended as an antihysteric, anti-theretic, &c. At present it is chiefly used as an anthelmintic.

Powdered tin. L.

Take of tin, six pounds. Melt it in an iron vessel, and stir it with an iron rod until a powder floats on the surface. Take off the powder, and, when cold, pass it through a sieve.

This preparation may be considered as nearly the same with the calx Jovis, which had a place in the former editions of the Edinburgh pharmacopoeia; but from the late editions the calx has been expunged, and the filings or powder of tin, has a place only in their list of the materia medica. But although seldom prepared by the apothecary himself, it is not unfrequently employed as a remedy against worms, particularly the flat kinds, which too often elude the force of other medicines. The general dose is from a scruple to a dram; some confine it to a few grains. But Dr Alston assures us, in the Edinburgh Essays, that its success chiefly depends on its being given in much larger quantities: he directs an ounce of the powder on an empty stomach, mixed with four ounces of molasses; next day, half an ounce; and the day following, half an ounce more; after which a cathartic is administered: he says the worms are usually voided during the operation of the purge, but that pains in the stomach occasioned by them are removed almost immediately upon taking the first dose of the tin.

This practice is sometimes successful in the expulsion of tenia, but by no means so frequently as Dr Alston's observations would lead us to hope.

Amalgama of tin. Dan.

Take of shavings of pure tin, two ounces; pure quicksilver, three drams. Let them be rubbed to a powder in a stone mortar.

Some have imagined that tin thus acted on by mercury is in a more active condition than when exhibited in a state of powder: and accordingly it has been given in worm cases. But as both are equally insoluble in the animal fluids, this is not to be expected; and to obtain any peculiar properties which tin may possess to their full extent, it will probably be necessary to exhibit it in some saline state.

Chap. XVI. Preparations of zinc and copper.

Calcined zinc. L.

Take of zinc, broken into small pieces, eight ounces. Cast the pieces of zinc, at several times, into an ignited, large, and deep crucible, placed leaning, or half-upright, putting on it another crucible in such a manner that the air may have free access to the burning zinc. Take out the calx as soon as it appears, and separate its white and lighter part by a fine sieve.

Flowers of zinc. E.

Let a large crucible be placed in a furnace, in an inclined situation, only half-upright; when the bottom of the vessel is moderately red, put a small piece of zinc, about the weight of two drams, into it. The zinc soon flames, and is at the same time converted into a spongy calx, which is to be raked from the surface of the metal with an iron spatula, that the combustion may proceed the more speedily: when the zinc ceases to flame, take the calx out of the crucible. Having put in another piece of zinc, the operation may be repeated as often as you please. Lastly, the calx is to be prepared like antimony. These flowers, as used externally, are preferable for medicinal purposes to tatty, and the more impure sublimes of zinc, which are obtained in the brass works; and likewise to calamine, the natural ore of this metal, which contains a large quantity of earth, and frequently a portion of heterogeneous metallic matter. But before being applied externally, they have also of late been used internally. The flowers of zinc, in doses from one to seven or eight grains, have been much celebrated of late years in the cure of epilepsy and several spasmodic affections: and there are sufficient testimonies of their good effects, where tonic remedies in those affections are proper.

White vitriol. E.

Take of zinc, cut into small pieces, three ounces; vitriolic acid, five ounces; water, twenty ounces; having mixed the acid and water, add the zinc, and when the ebullition is finished strain the liquor; then after proper evaporation let it apart in a cold place, that it may shoot into crystals.

This salt is an elegant white vitriol. It differs from the common white vitriol, and the salt of vitriol of the shops, only in being purer, and perfectly free from any admixture of copper, or such other foreign metallic bodies as the others generally contain.

Purified vitriolated zinc. L.

Take of white vitriol, one pound; vitriolic acid, one dram; boiling distilled water, three pints. Mix, and filter through paper. After a proper evaporation, let it aside in a cold place to crystallize.

Although the Edinburgh college have given a formula for the preparations of white vitriol, yet their direction is very rarely followed by any of the apothecaries or chemists, who in general purchase it as obtained from the Goslar mines. When, however, it is got in this way, it is often a very impure salt, and requires

The process which has been judged most analogous to that of nature, is the following. The subject is gathered at the season of its greatest vigour, with the morning dew on it, is laid lightly and unbruised in a shallow vessel, to which is adapted a low head with a recipient; under the vessel a live coal is placed, and occasionally renewed, so as to keep up an uniform heat, no greater than that which obtains in the atmosphere in summer, viz. about 85 degrees of Fahrenheit's thermometer. In this degree of heat there arises exceeding slowly an invisible vapour, which condenses in the head into dewy drops, and falls down into the receiver; and which has been supposed to be the very substance that the plant would have spontaneously emitted in the open air.

But on submitting many kinds of odoriferous vegetables to this process, the liquors obtained by it have been found to be very different from the natural effluvia of the respective subjects: they have had very little smell, and no remarkable taste. It appeared that a heat, equal to that of the atmosphere, is incapable of raising in close vessels those parts or vegetables which they emit in the open air. It may therefore be presumed, that in this last case some other cause concurs to the effect: that it is not the sun's heat alone which raises and impregnates the air with the odorous principles of vegetables, but that the air itself, or the watery humidity with which it abounds, acting as a true solvent, extracts and imbibes them; so that the natural effluvia of a plant may be considered as an infusion of the plant made in air. The purgative virtue of the damask rose, and the astringency of the walnut-tree, which, as above observed, are in some degree communicated to the air, may be totally extracted by infusion both in watery and spirituous menstrua, but never rise in distillation with any degree of heat; and the volatile odours of aromatic herbs, which are diffused through the atmosphere in the lowest warmth, cannot be made to distil without a heat much greater than is ever found to obtain in a shaded air.

We apprehend, that the effluvia arising from growing vegetables are chiefly exhaled by the living energy of the plant: the odorous matter is a real secretion, which cannot be performed independent of active vessels; and it is as reasonable to allow the same powers for the exhalation of these effluvia, as for the transpiration of their watery parts.

The above process, therefore, and the theory on which it is built, appear to be faulty in two points: 1. In supposing that all these principles, which naturally exhale from vegetables, may be collected by distillation; whereas there are many which the air extracts in virtue of its solvent power; some are also incapable of being collected in a visible and inelastic form; and some are artificially separable by solvents only: 2. In employing a degree of heat insufficient for separating even those parts which are truly exhalable by heat.

The foregoing method of distillation is commonly called distillation by the cold still; but those who have practised it have generally employed a considerable heat. A shallow leaden vessel is filled with the fresh herbs, flowers, &c., which are heaped above it; so that when the head is fitted on, this also may be filled a considerable way. A little fire is made under the ves- sufficient to make the bottom much hotter than the hand can bear, care being only taken not to heat it so far as to endanger scorching any part of the subject. If the bottom of the vessel be not made so hot as to have this effect on the part contiguous to it, it is not to be feared that the heat communicated to the rest of the included matter will be so great as to do it any injury. By this management, the volatile parts of several odorous plants, as mint, are effectually forced over; and if the process has been skilfully managed, the distilled liquor proves richly impregnated with the native odour and flavour of the subject, without having received any kind of disagreeable impression from the heat used.

This process has been chiefly practised in private families; the slovenly distillation, and the attendance and care necessary for preventing the scorching of some part of the plant, so as to communicate an ungrateful burnt flavour to the liquor, rendering it inconsistent with the dispatch requisite in the larger way of business.

Another method has therefore been had recourse to, viz. by the common still, called, in distinction from the foregoing, the hot still. Here a quantity of water is added to the plant to prevent its burning; and the liquor is kept nearly of a boiling heat, or made to boil fully, so that the vapour rises plentifully into the head, and passing thence into a spiral pipe or worm placed in a vessel of cold water, is there condensed, and runs out in drops quickly succeeding each other, or in a continued stream. The additional water does not at all weaken the produce; for the most volatile parts of the subject rise first, and impregnate the liquor that first distils: as soon as the plant has given over its virtue sufficiently, which is known by examining from time to time the liquor that runs from the nole of the worm, the distillation is to be stopped.

This is the method of distillation commonly practised for the officinal waters. It is accompanied with one imperfection, affecting chiefly those waters whose principal value consists in the delicacy of their flavour; this being not a little injured by the boiling heat usually employed, and by the agitation of the odorous particles of the subject with the water. Sometimes also a part of the plant sticks to the sides of the still, and is so far scorched as to give an ungrateful taint to the liquor.

There is another method of managing this operation, which has been recommended for the distillation of the more volatile essential oils, and which is equally applicable to that of the waters. In this way, the advantages of the foregoing methods are united, and their inconveniences obviated. A quantity of water being poured into the still, and the herbs or flowers placed in a basket over it, there can be no possibility of burning; the water may be made to boil, but so as not to rise up into the basket, which would defeat the intention of this contrivance. The hot vapour of the water passing lightly through all the interfaces of the subject matter, imbibes and carries over the volatile parts unaltered in their native flavour. By this means the distilled waters of all those substances whose oils are of the most volatile kind, are obtained in the utmost perfection, and with sufficient dispatch; for which last intention the still may be filled quite up to the head.

In the distillation of essential oils, the water, as was observed in the foregoing section, imbibes always a part of the oil. The distilled liquors here treated of, are no other than water thus impregnated with the essential oil of the subject; whatever smell, taste, or virtue is here communicated to the water, or obtained in the form of a watery liquor, being found in a concentrated state in the oil. The essential oil, or some part of it, more attenuated and subtilized than the rest, is the direct principle on which the title of spiritus rectus, or preëeding spirit, has been bestowed.

All those vegetables therefore which contain an essential oil, will give over some virtue to water by distillation: but the degree of the impregnation of the water which a plant is capable of saturating with its virtue, are by no means in proportion to the quantity of its oil. The oil saturates only the water that comes over at the same time with it; if there be more oil than is sufficient for this saturation, the surplus separates, and concretes in its proper form, not miscible with the water that arises afterwards. Some odoriferous flowers, whose oil is in so small quantity, that scarcely any visible mark of it appears, unless fifty or an hundred pounds or more are distilled at once, give nevertheless as strong an impregnation to water as those plants which abound most with oil.

Many have been of opinion, that distilled waters may be more and more impregnated with the virtues of the subject, and their strength increased to any assigned degree, by colobation, that is, by redistilling them a number of times from fresh parcels of the plant. Experience, however, shows the contrary; a water skillfully drawn in the first distillation, proves on every repeated one not stronger but more disagreeable. Aqueous liquors are not capable of imbibing above a certain quantity of the volatile oil of vegetables; and this they may be made to take up by one as well as by any number of distillations; the oftener the process is repeated, the ungrateful impression which they generally receive from the fire, even at the first time, becomes greater and greater. Those plants, which do not yield at first waters sufficiently strong, are not proper subjects for this process, since their virtue may be obtained much more advantageously by others.

General rules for the distillation of the officinal simple waters.

1. Where they are directed fresh, such only must be employed: but some are allowed to be used dry, as being easily procurable in this state at all times of the year, though rather more elegant waters might be obtained from them while green.

When fresh and juicy herbs are to be distilled, thrice their weight of water will be fully sufficient; but dry ones require a much larger quantity. In general, there should be so much water, that after all intended to be distilled has come over, there may be liquor enough left to prevent the matter from burning to the still.

Plants differ so much, according to the soil and season of which they are the produce, and likewise according to their own age, that it is impossible to fix the quantity of water to be drawn from a certain weight of them to any invariable standard. The distillation may always be continued as long as the liquor runs well flavoured off the subject, and no longer.

2. The distillation may be performed in an alembic with a refrigeratory, the junctures being luted.

3. If the herbs are of prime goodness, they must be taken in the weights prescribed; but when fresh ones are substituted for dry, or when the plants themselves are the produce of unfavourable seasons, and weaker than ordinary, the quantities are to be varied according to the discretion of the artist.

After the odorous water, alone intended for use, has come over, an acidulous liquor arises, which has sometimes extracted so much from the copper head of the still as to prove emetic. To this are owing the anthelmintic virtues attributed to certain distilled waters.

4. In a preceding edition of the Edinburgh pharmacopoeia, some vegetables were ordered to be slightly fermented with the addition of yeast previously to the distillation.

The principle on which this management is founded, is certainly just; for the fermentation somewhat opens and unlocks their texture, so as to make them part with more in the subsequent distillation than could be drawn over from them without some assistance of this kind. Those plants, however, which require this treatment, are not proper subjects for simple waters to be drawn from, their virtues being obtainable to better advantage by other processes.

5. If any drops of oil swim on the surface of the water, they are to be carefully taken off.

6. That the waters may keep the better, about a 20th part their weight of proof-spirit may be added to each after they are distilled.

A great number of distilled waters were formerly kept in the shops, and are still retained in foreign pharmacopeias. The faculty of Paris direct, in the last edition of their Codex Medicamentarius, no less than 125 different waters, and 130 different ingredients in one single water. Nearly one half of these preparations have scarcely any virtue or flavour from the subject, and many of the others are insignificant.

The colleges of London and Edinburgh have rejected these ostentatious superfluities, and given an elegant and compendious set of waters, sufficient for answering such purposes as these kinds of preparations are applied to in practice. Distilled waters are employed chiefly as grateful diluents, as suitable vehicles for medicines of greater efficacy, or for rendering disgustful ones more acceptable to the palate and stomach; few are depended on, with any intention of consequence, by themselves.

**Distilled water. L.**

Take of spring-water, 10 gallons. Draw off by distillation, first, four pints; which being thrown away, draw off four gallons. This water is to be kept in a glass or earthen bottle with a glass stopper.

**Distilled water. E.**

Let well or river water be distilled in very clean vessels till about two thirds are drawn off.

Native water is seldom or never found pure, and generally contains earthy, saline, metallic, or other matters. Distillation is therefore employed as a means of freeing it from these heterogeneous parts. For some pharmaceutical purposes distilled water is absolutely necessary; thus, if we employ hard undistilled water for dissolving sugar of lead, instead of a perfect solution, we produce a milky-like cloud, owing to a real decomposition of parts.

Distilled water is now employed by the London college for a great variety of purposes; and there can be no doubt, that in many chemical and pharmaceutical processes, the employment of a heterogeneous fluid, in place of the pure element, may produce an essential alteration of qualities, or frustrate the intention in view. While the London college have made more use of distilled water than any other, their directions for preparing it seem to be the best. For as some impregnations may be more volatile than pure water, the water may be freed from them by throwing away what comes first over; and by keeping it afterwards in a close vessel, absorption from the air is prevented.

**Dill-water. L.**

Take of dill-seed, bruised, one pound; water, sufficient to prevent an empyreuma. Draw off one gallon.

**Simple dill-seed water. E.**

Take of dill-seeds, one pound; pour on as much water as when ten pounds have been drawn off by distillation there may remain as much as is sufficient to prevent an empyreuma. After proper maceration, let ten pounds be drawn off.

Although the dill-water holds a place, not only in the London and Edinburgh pharmacopoeias, but also in most of the foreign ones; yet it is not much employed in practice. It obtains, indeed, a pretty strong impregnation from the seeds, and is sometimes employed as a carminative, particularly as the basis of mixtures and juleps; but it is less powerful and less agreeable than that of peppermint, cinnamon, and some others.

**Cinnamon-water. L. E.**

Take of cinnamon, bruised, one pound; water, sufficient to prevent an empyreuma. Macerate for 24 hours, and draw off one gallon.

From one pound of cinnamon the Edinburgh college direct 10 pounds of water to be drawn off; and if the cinnamon employed be of good quality, it may yield that quantity with a strong impregnation; but what comes over first is unquestionably the strongest.

This is a very grateful and useful water, possessing in an eminent degree the fragrance and aromatic cordial virtues of the spice. Where real cinnamon-water is wanted, care should be had in the choice of the cinnamon, to avoid the too common imposition of cassia being substituted in its room. The two drugs may be easily distinguished from each other by a variety of marks, which it is needless to introduce in this place. See Cassia and Cinnamon. But the essential oils of the two approach so near, that after distillation it is perhaps impossible to distinguish the waters; and it is still more doubtful how far the one is in any degree preferable to the other. The oil of cinnamon is very ponderous, and arises more difficultly than that of any other of the vegetable matters from which simple writers are ordered to be drawn. This observation directs us, in the distillation of this water, to use a quick fire and a low vessel. For the same reason, the water does not keep so well as might be wished; the ponderous oil parting from it in time, and falling to the bottom, when the liquor loses its milky hue, its fragrant smell, and aromatic taste. Some recommend a small proportion of sugar to be added, in order to keep the oil united with the water.

**Cassia-water.** E.

From a pound and a half of the cassia bark, ten pounds of water are directed to be drawn off in the same manner as the dill-water.

This distilled water, as we have already observed, when properly prepared, approaches so near to that of cinnamon, that it is almost, if not altogether, impossible to distinguish the difference between the two. And although the London college has given it no place in their pharmacopoeia, yet we may venture to assert, that it is no stranger to the shops of the apothecaries. Nay, so great is the difference of price, and the sensible qualities so nearly alike, that what is sold under the name of cinnamon-water is almost entirely prepared from cassia alone; and not even prepared from the cassia bark, as directed by the Edinburgh college, but from the cassia buds, which may be had at a still cheaper rate, and which yield precisely the same essential oil, although in less quantity. When cassia-water is prepared precisely according to the directions of the Edinburgh college, from containing a larger proportion of the subject, it has in general a stronger impregnation than their genuine cinnamon-water, and is probably in no degree inferior in its virtues.

**Fennel-water.** L.

Take of sweet fennel seeds, bruised, one pound; water, sufficient to prevent an empyreuma. Draw off one gallon.

The water of fennel seeds is not unpleasant. A water has also been distilled from the leaves. When these are employed, they should be taken before the plant has run into flower; for after this time they are much weaker and less agreeable. Some have observed, that the upper leaves and tops, before the flowers appear, yield a more elegant water, and a remarkably finer essential oil than the lower ones; and that the oil obtained from the one swims on water, while that of the other sinks. No part of the herb, however, is equal in flavour to the seeds.

**Peppermint-water.**

Take of herb of peppermint, dried, one pound and an half; water, sufficient to prevent an empyreuma. Draw off one gallon. L.

From three pounds of the leaves of peppermint, ten pounds of water are to be drawn off. E.

This is a very elegant and useful water. It has a warm pungent taste, exactly resembling that of the peppermint itself. A spoonful or two taken at a time warm the stomach, and give great relief in cold flatulent colics. Some have substituted a plain infusion of the dried leaves of the plant, which is not greatly different in virtue from the distilled water.

In the distillation of this water, a considerable quantity of essential oil generally comes over in its pure state. And it is not uncommon to employ this for impregnating other water, with which it may be readily mixed by the aid of a little sugar.

**Spearmint-water.** L.

Take of spearmint, dried, one pound and an half; water, sufficient to prevent an empyreuma. Draw off one gallon.

The Edinburgh college directs this water to be made in the same proportion as the preceding. But probably three pounds of the fresh herb will not give a stronger impregnation than a pound and a half of the dried; so that the water of the London college may be considered to be as strongly impregnated as that of the Edinburgh college.

This water smells and tastes very strongly of the mint; and proves in many cases an useful stomachic. Boerhaave commends it (cohabated) as a pleasant and incomparable remedy for strengthening a weak stomach, and curing vomiting proceeding from cold viscid phlegm, and also in lienteries.

**All-spice water.** L. E.

Take of all-spice, bruised, half a pound; water, sufficient to prevent an empyreuma. Macerate for 24 hours, and draw off one gallon.

From half a pound of the pimento the Edinburgh college directs ten pounds of water to be drawn off; so that the impregnation is there somewhat weaker than the above.

This distilled water is a very elegant one, and has of late come pretty much into use; the hospitals employ it as a succedaneum to the more costly spice-waters. It is, however, inferior in gratefulness to the spirituous water of the same spice hereafter directed.

**Pennyroyal-water.** L. E.

Take of dried herb pennyroyal, one pound and an half; water, sufficient to prevent an empyreuma. Draw off one gallon.

The pennyroyal-water is directed to be prepared by the Edinburgh college in the same proportions as the mint and peppermint. Whether prepared from the recent or dried plant, it possesses in a considerable degree the smell, taste, and virtues, of the pennyroyal. It is not unfrequently employed in hysterical cases, and sometimes with a good effect.

**Rose-water.** L. E.

Take of fresh petals of the damask rose, the white heels being cut off, six pounds; water, sufficient to prevent an empyreuma. Draw off one gallon.

From the same quantity the Edinburgh college direct ten pounds to be drawn off.

This water is principally valued on account of its fine flavour, which approaches to that generally admired in the rose itself. The purgative virtue of the roses remains entire in the liquor left in the still, which has therefore been generally employed for making the foliute honey and syrup, instead of a decoction or infusion of fresh roses prepared on purpose; and this piece... piece of frugality the college have now admitted. A distilled water of red roses has been sometimes called for in the shops, and supplied by that of damask roses diluted with common water. This is a very venial substitution; for the water drawn from the red rose has no quality which that of the damask does not possess in a far superior degree; neither the purgative virtue of the one nor the astringency of the other arising in distillation.

Lemon-peel-water. E.

From two pounds of recent lemon peel ten pounds of water are to be drawn off by distillation.

Orange peel-water. E.

From two pounds of orange-peel ten pounds of water are directed to be drawn off.

Neither of these distilled waters are now to be met with in the London pharmacopoeia; and it is probable that no great loss arises from the want of them, for both the one and the other contain only a very weak impregnation. They are chiefly employed as diluents in fevers and other disorders where the stomach and palate are very apt to be disquieted. And perhaps the only circumstance for which they are valuable is the slightness of the impregnation; for in such affections, any flavour, however agreeable at other times, often becomes highly disagreeable to patients.

The distilled waters above noticed are the whole that have now a place in the pharmacopoeias of the London and Edinburgh colleges; and perhaps this selection is sufficiently large for answering every useful purpose. But besides these, a considerable number of others are still retained even in the modern foreign pharmacopoeias; some of which at least it may not be improper to mention.

Alexiterial water. Brun.

Take of elder flowers, moderately dried, three pounds; angelica leaves, fresh gathered, two pounds; spring water, forty pounds. Draw off, by distillation, thirty pounds.

This water is sufficiently elegant with regard to taste and smell; though few expect from it such virtues as its title seems to imply. It is used occasionally for vehicles of alexipharmac medicines, or in juleps to be drank after them, as coinciding in the intention; but in general is not supposed to be itself of any considerable efficacy.

Camphor-water. Brun.

Take of camphor, an ounce and an half. Let it be dissolved in half an ounce of the spirit of rosemary, then pour on it two pounds of spring water, and draw off by distillation a pound and an half.

This distilled water, which has no place in our pharmacopoeias, is introduced into some of the foreign ones. And since camphor may be considered as a concrete essential oil, it naturally occurs as a form under which that medicine may be introduced with advantage in a diluted state.

Caster-water. Brun.

Take of Russia caster, one ounce; water, as much as will prevent burning. Draw off two pints.

Castor yields almost all its flavour in distillation to pure water, but treated in the same manner with spirit of roses and wine gives over nothing. The spirit of castor formerly kept in the shops had none of the smell or virtues of the drug; while the water here directed proves, when fresh drawn, very strong of it.

It is remarkable, that the virtues of this animal-substance reside in a volatile oil, analogous to the essential oils of vegetables. Some are reported to have obtained, in distilling large quantities of this drug, a small portion of oil, which smelt extremely strong of the castor, and diffused its ungrateful scent to a great distance.

This water is used in hysterical cases, and some nervous complaints, though it has not been found to answer what many people expect from it. It loses greatly of its flavour in keeping.

And it is probably from this circumstance that it has no place either in our pharmacopoeias or in the modern foreign ones; but at the same time, as professing in a high degree the sensible qualities of the castor, it may be considered as justly deserving future attention.

Chervil-water. Gen.

Take of fresh leaves of chervil, one pound; spring water, as much as is sufficient for allowing eight pounds to be drawn off by distillation, at the same time avoiding empyreuma.

Although the chervil be but little employed in Britain, yet among some of the foreigners it is held in high esteem; and the distilled water is perhaps one of the most elegant forms under which its active parts can be introduced. But there is reason to believe that those diuretic powers, for which it has been chiefly celebrated, will be most certainly obtained from exhibiting it in substance, or under the form of the expressed juice of the recent plant.

Black-cherry-water. Succ.

Take of ripe black cherries bruised with the kernels, twenty pounds; pure water, as much as is sufficient for avoiding empyreuma. Draw off twenty pounds by distillation.

This water, although now banished from our pharmacopoeias, has long maintained a place in the foreign ones, and even in Britain it is not unfrequently to be met with in the shops. It has often been employed by physicians as a vehicle, in preference to the other distilled waters; and among nurses who have the care of young children has been the first remedy against the convulsive disorders to which infants are so often subject.

This water has nevertheless of late been brought into disrepute, and has been esteemed poisonous. They observe, that it receives its flavour principally from the cherry stones; and that these kernels, like many others, bear a resemblance in taste to the leaves of the laurel cerasus, which have been discovered to yield, by infusion or distillation, the most sudden poison known. Some physicians of Worcester have lately found, by trial purposely made, that a distilled water very strongly impregnated with the flavour of the cherry kernels (no more than two pints being distilled from fourteen pounds of the cherry stones) proved in like manner poisonous to brutes. The London college repeated the same experiment, and found the effects agreeable to those gentlemen's report.

It by no means follows from these trials, nor after such long experience can it be imagined, that black-cherry-water, when no stronger than the shops have been accustomed to prepare it, is unsafe. These kernels plainly resemble opium, and some other things, which poison only when taken in too great a quantity. The water from the very laurel leaves is harmless when duly diluted; and even spirit of wine proves a poison of its kind not greatly different, if drank to a certain degree of excess. Nor can it be concluded, from the trials with the strong black-cherry water on dogs, &c., that even this will have the same effects in the human body; the kernels of many sorts of fruits being in substance poisonous to brutes, though innocent to man.

It is possible, however, that this water in any degree of strength may not be altogether safe to the tender age of infants, where the principles of life are but just beginning as it were to move. It is possible that it may there have had pernicious effects without being suspected; the symptoms it would produce, if it should prove hurtful, being such as children are often thrown into from the disease which it is imagined to relieve. On these considerations, both the London and Edinburgh colleges have chosen to lay it aside; more especially as it has been too often counterfeited with a water distilled from bitter almonds, which are known to communicate a poisonous quality. It is, however, one of those active articles which may perhaps be considered as deserving farther attention.

Camomile-flower water. Dan.

Take of camomile flowers, dried in the shade, eight pounds; water, 72 pounds. Draw off by gentle distillation 48 pounds.

Camomile flowers were formerly ordered to be fermented previously to the distillation, a treatment which they do not need; for they give over, without any fermentation, as much as that process is capable of enabling them to do. In either case the smell and peculiar flavour of the flowers arise without any of the bitterness, this remaining behind in the decoction; which, if duly depurated and infusified, yields an extract similar to that prepared from the flowers in the common manner. The distilled water has been used in flatulent colics and the like, but is at present held in no great esteem.

Strawberry-water. Succ.

From 20 pounds of strawberries 20 pounds of distilled water are drawn off, according to the same directions given for the preparation of the black cherry water. Water thus impregnated with the essential oil of the strawberries some people will think of a very agreeable flavour, but any considerable medical power is not to be expected from it.

Hyssop-water. Succ.

From four pounds of the fresh leaves of hyssop six pounds of water are drawn off.

Hyssop-water has been held by some in considerable esteem as an uterine and pectoral medicine. It was directed in a former edition of the Edinburgh pharmacopoeia for making up the black pectoral troches, but is now exchanged for common water. Few at present expect any singular virtues from it, nor is it often to be met with in our shops, being now expunged from our pharmacopoeia. It holds a place, however, in most of the foreign ones, and among ourselves there are still some practitioners who frequently employ it. But there can be no doubt that those medical properties which the hyssop contains may be more readily and effectually extracted by simple infusion.

White-lily water. Brun.

Lily-of-the-valley water. Brun.

To any quantity of these flowers four times their weight of water is to be added, and water drawn off by distillation in the proportion of two pounds to each pound of the flowers.

These waters must obtain some impregnation of that elegant essential oil on which the odour of flowers in their growing state depends. But they do not possess any remarkable medical properties.

Balm-water. Brun.

The green leaves of the balm are to be macerated with double their weight of water; and from each pound of the plant a pound and an half of water is to be drawn off.

This water contains a considerable impregnation from the balm, which yields its essential oil pretty freely on distillation. Though now banished from our pharmacopoeias, it has still a place in most of the foreign ones. In the old editions of the Edinburgh pharmacopoeia, this water was ordered to be cohoberated or redistilled from fresh quantities of the herb. This management seems to have been taken from Boerhaave, who has a very high opinion of the water thus prepared; he says, he has experienced in himself extraordinary effects from it taken on an empty stomach; that it has scarce its equal in hypochondriacal and hysterical cases, the cholera, and palpitation of the heart, as often as those diseases proceed from a disorder of the spirits, rather than from any collection of morbid matter.

But whatever virtues are lodged in balm, they may be much more perfectly and advantageously extracted by cold infusion in aqueous or spirituous menstrua: in this last process, the liquor suffers no injury from being returned on fresh parcels of the herb; a few repetitions will load it with the virtues of the subject, and render it very rich. The impregnation here is almost unlimited; but in distilled waters it is far otherwise.

Rue-water. Ross.

From each pound of rue, with a sufficient quantity of spring-water to prevent empyreuma, two pounds of distilled water are to be drawn.

Rue gives over in this process the whole of its smell, and great part of its pungency. The distilled water stands recommended in epileptic cases, the hysterical passion, for promoting perspiration, and other natural secretions. But though it is a good deal employed abroad, it is with us falling into disrepute. Savin-water.

This is distilled from the fresh leaves of savin, after the same manner as the other already mentioned.

This water is by some held in considerable esteem for the same purpose as the distilled oil of savin. Boerhaave relates, that he has found it (when prepared by cohabitation) to give an almost incredible motion to the whole nervous system; and that, when properly used, it proves eminently serviceable for promoting the menstres and the hemorrhoidal flux.

It has now, however, fallen so much into disrepute as to have no place either in our pharmacopoeias or in the best modern foreign ones: But at the same time, when we reflect how readily savin yields a large proportion of active essential oil on distillation, it may perhaps be considered as better intitled to attention than some other distilled waters which are still retained.

Elderflower water. Brun.

This is distilled from fresh elder flowers, after the same manner as the white-lily water.

This water smells considerably of the flowers; but is rarely used among us.

Sage-water. Brun.

This is directed to be prepared from the green leaves of the sage in the same manner as the balm water.

Sage leaves contain a considerable proportion of essential oil, which they yield pretty freely on distillation. But their whole medical properties may with still greater ease and advantage be extracted by simple infusion.

To the simple distilled waters the London college have annexed the following remarks.

We have ordered the waters to be distilled from the dried herbs, because fresh are not ready at all times of the year. Whenever the fresh are used, the weights are to be increased. But, whether the fresh or dried herbs be employed, the operator may vary the weight according to the season in which they have been produced and collected.

Herbs and seeds kept beyond the space of a year are less proper for the distillation of waters.

To every gallon of these waters add five ounces, by measure, of proof-spirit.

Chap. XVIII. Distilled Spirits.

The flavours and virtues of distilled waters are owing, as was observed in the preceding chapter, to their being impregnated with a portion of the essential oil of the subject from which they are drawn. Spirit of wine, considered as a vehicle for these oils, has this advantage above water, that it is their proper menstruum, and keeps all the oil that rises with it perfectly dissolved into an uniform limpid liquor.

Nevertheless, many substances, which, on being distilled with water, impart to it their virtues in great perfection; if treated in the same manner with spirit of wine, scarcely give it any smell or taste. This difference proceeds from hence, that spirit is not susceptible of so great a degree of heat as water. Liquids in general, when made to boil, have received as great a heat as they are capable of sustaining: now, if the extent of heat between freezing and boiling water, as measured by thermometers, be taken for a standard, spirit of wine will be found to boil with less than four-fifths of that heat, or above one-fifth less than the heat of boiling water. It is obvious, therefore, that substances may be volatile enough to rise with the heat of boiling water, but not with that of boiling spirit.

Thus, if cinnamon, for instance, be committed to distillation with a mixture of spirit of wine and water, or with a pure proof-spirit, which is no other than a mixture of about equal parts of the two; the spirit will rise first, clear, colourless, and transparent, and almost without any taste of the spice; but as soon as the more ponderous watery fluid begins to rise, the oil comes over freely with it, so as to render the liquor highly odorous, lapid, and of a milky hue.

The proof-spirits usually met with in the shops are accompanied with a degree of ill flavour; which, though concealed by means of certain additions, plainly discovers itself in distillation. This nauseous relish does not begin to rise till after the purer spirituous part has come over; which is the very time that the virtues of the ingredients begin also most plentifully to distil: and hence the liquor receives an ungrateful taint. To this cause principally is owing the general complaint, that the cordials of the apothecary are less agreeable than those of the same kind prepared by the distiller; the latter being extremely curious in rectifying or purifying the spirits (when designed for what he calls fine goods) from all ill flavour.

Ardent spirit. L.

Take of rectified spirit of wine, one gallon; kali, made hot, one pound and an half; pure kali, one ounce. Mix the spirit of wine with the pure kali, and afterwards add one pound of the hot kali; shake them, and digest for twenty-four hours. Pour off the spirit, to which add the rest of the kali, and distil in a water bath. It is to be kept in a vessel well stopped. The specific gravity of the alcohol is to that of distilled water as 815 to 1000.

We have already offered some observations on spirit of wine both in the state of what is called rectified and proof-spirit. But in the present formula we have ardent spirit still more freed from an admixture of water than even the former of these. And in this state it is unquestionably best fitted for answering some purposes. It may therefore be justly considered as an omission in the present edition of the Edinburgh pharmacopoeia, that they have no analogous form. In former editions of this work, alcohol was directed to be prepared from French brandy. But this is rather too dear an article in this country for distillation; nor is the spirit obtained from it anywise preferable to one procurable from cheaper liquors. The coarser inflammable spirits may be rendered perfectly pure, and fit for the nicest purposes, by the following method.

If the spirit be exceedingly foul, mix it with about an equal quantity of water, and distil with a slow fire; discontinuing the operation as soon as the liquor begins to run milky, and discovers by its nauseous taste that the impure and phlegmatic part is rising. By this treatment, the spirit leaves a considerable portion of its foul oily matter behind it in the water, which now appears milky and turbid, and proves highly disagreeable to the taste. If the spirit be not very foul at first, this ablation is not necessary; if extremely so, it will be needful to repeat it once, twice, or oftener.

As vinous spirits arise with a less degree of fire than watery liquors, we are hence directed to employ, in the distillation of them, a heat less than that in which water boils; and if due regard be had to this circumstance, very weak spirits may, by one or two wary distillations, be tolerably well freed from their aqueous phlegm; especially if the distilling vessels are of such a height, that the spirit, by the heat of a water-bath, may but just pass over them: in this case, the phlegmatic vapours which rise for a little way along with the spirit, will condense and fall back again before they can come to the head. Very pompous instruments have been contrived for this purpose, and carried in a spiral or serpentine form to an extraordinary height. The spirit ascending through these, was to leave all the watery parts it contained in its passage, and come over perfectly pure and free from phlegm. But these instruments are built upon erroneous principles, their extravagant height defeating the end it was designed to answer: if the liquor be made to boil, a considerable quantity of mere phlegm will come over along with the spirit; and if the heat be not raised to this pitch, neither phlegm nor spirit will distil. The most convenient instrument is the common still; between the body of which and its head an adopter or copper tube may be fixed.

The spirit being washed, as above directed, from its foul oil, and freed from the greatest part of the phlegm by gentle distillation in a water-bath, add to every gallon of it a pound or two of pure dry fixed alkaline salt. Upon digesting these together for a little time, the alkali, from its known property of attracting water and oils, will imbibe the remaining phlegm, and such part of the disagreeable unctuous matter as may still be left in the spirit, and will sink with them to the bottom of the vessel. If the spirit be now again gently drawn over, it will rise entirely free from its phlegm and nauseous flavour; but some particles of the alkaline salt are apt to be carried up with it, and give what the workmen call an urinous relish: this may be prevented by adding, previous to the last distillation, a small proportion of calcined vitriol, alum, or bitter cathartic salt; the acids of these salts will unite with and neutralize the alkali, and effectually prevent it from rising; while no more of the acid of the salts is extricated than what the alkali absorbs.

The spirit obtained by this means is extremely pure, limpid, perfectly flavourless, and fit for the finest purposes. It may be reduced to the strength commonly understood by proof, by mixing twenty ounces of it with seventeen ounces of water. The distilled cordials made with these spirits prove much more elegant and agreeable than when the common rectified or proof-spirits of the shops are used.

If the rectified spirit be distilled afresh from dry alkaline salt with a quick fire, it brings over a considerable quantity of the salt; and in this state it is supposed to be a more powerful menstruum for certain substances than the pure spirit. This alkalized spirit is called tartarized spirit of wine.

The processes here described, which was long since recommended by Dr Lewis, will sufficiently explain the intention of the London college, in the directions they have now given for the preparation of alcohol. And there can be no doubt, that by their process a very pure alcohol may be obtained. Of this we have a sufficient tell in the specific gravity of the fluid which comes over, which is to that of distilled water only as 815 to 1000, while the specific gravity of proper rectified spirit is as 835 to 1000.

Spirit of vitriolic ether. L.

Take of rectified spirit of wine, vitriolic acid, each one pound. Pour by a little at a time the acid on the spirit, and mix them by shaking; then from a retort through a tubulated receiver, to which another recipient is fitted, distil the spirit of vitriolic ether till fulphurous vapours begin to rise.

Vinous vitriolic acid, commonly called dulcified spirit of vitriol. E.

Take of vitriolic ethereal liquor, one part; rectified spirit of wine, two parts. Mix them.

The last of these processes is a very ready and convenient method of preparing the dulcified spirit of vitriol, which only differs from ether by the acid being more predominant, and less intimately combined.

In the first process, a good deal of caution is requisite in mixing the two liquors. Some direct the spirit of wine to be put first into the retort, and the oil of vitriol to be poured upon it all at once; a method of procedure by no means advisable, as a violent heat and ebullition always ensue, which not only dissipate a part of the mixture, but hazard also the breaking of the vessel, to the great danger of the operator. Others put the oil of vitriol into the retort first; then by means of a funnel, with a long pipe that may reach down just to the surface of the acid, pour in the spirit of wine; if this be done with sufficient caution, the vinous spirit spreads itself on the surface of the oil of vitriol, and the two liquors appear distinct. On standing for a week or two, the vinous spirit is gradually imbibed, without any commotion, and the vessel may then be safely shaken to complete the mixture: but if the spirit be poured in too hastily at first, or if the vessel be moved before the two liquors have in some degree incorporated, the same effect ensues as in the foregoing case. The only secure way is, to add the oil of vitriol to the spirit of wine by a little quantity at a time, waiting till the first addition be incorporated before another quantity is put in: by this management, the heat that ensues is inconsiderable, and the mixture is effected without any inconvenience.

The distillation should be performed with an equal and very gentle heat, and not continued so long as till a black froth begins to appear: for before this time a liquor will arise of a very different nature from the spirits here intended. The several products are most commodiously kept apart by using a tubulated receiver, so placed, that its pipe may convey the matter which shall come over into a vial set underneath. The junction of the retort and recipient is to be luted with a patte paste made of linseed meal, and further secured by a piece of wet bladder; the lower juncture may be closed only with some soft wax, that the vial may be occasionally removed with ease.

The true dulcified spirit arises in thin subtile vapours, which condense on the sides of the recipient in straight strata. It is colourless as water, very volatile, inflammable, of an extremely fragrant smell, in taste somewhat aromatic.

After the fire has been kept up for some time, white fumes arise; which either form irregular fires, or are collected into large round drops like oil. On the first appearance of these, the vial, or the receiver, if a common one is used, must be taken away. If another be substituted, and the distillation continued, an acid liquor comes over, of an exceeding pungent smell, like the fumes of burning brimstone. At length a black froth begins hastily to arise, and prevents carrying the process further.

On the surface of the sulphurous spirit is found swimming a small quantity of oil, of a light yellow colour, a strong, penetrating, and very agreeable smell. This oil seems to be nearly of the same nature with the essential oils of vegetables. It readily and totally dissolves in rectified spirit of wine, and communicates to a large quantity of that menstruum the taste and smell of the aromatic or dulcified spirit.

The matter remaining after the distillation is of a dark blackish colour, and still highly acid. Treated with fresh spirit of wine, in the same manner as before, it yields the same production; till at length all the acid that remains unvolatileized being saturated with the inflammable oily matter of the spirit, the compound proves a bituminous sulphurous mass; which, exposed to the fire in open vessels, readily burns, leaving a considerable quantity of fixed ashes; but in close ones it explodes with violence; with fixed alkaline salts it forms a compound nearly similar to one composed of zikalix and sulphur.

The new names adopted by the London and Edinburgh colleges for this fluid, are expressive of its composition; the one employing the term of spiritus athri vitriolici, the other of acidi vitriolicum vinum: the old term of spiritus vitrioli dulcis is less properly fitted to distinguish it from other fluids, and to convey a just idea of its nature.

Dulcified spirit of vitriol has been for some time greatly esteemed, both as a menstruum and a medicine. It dissolves some refrinous and bituminous substances more readily than spirit of wine alone, and extracts elegant tinctures from sundry vegetables. As a medicine, it promotes perspiration, and the urinary secretion, expels flatulencies, and in many cases abates spasmodic strictures, eases pains, and procures sleep. The dose is from ten to eighty or ninety drops in any convenient vehicle. It is not essentially different from the celebrated anodyne liquor of Hoffman; to which it is, by the author himself, not unfrequently directed as a succedaneum.

Of this fluid, however, or at least of an article still more nearly resembling it, we shall afterwards have occasion to speak, when we treat of the vinous spirit of vitriolic ether.

Vitriolic ether. I.

Take of the spirit of vitriolic ether, two pounds; wa- the quantity of half an ounce, in a glass of wine or water; which should be swallowed as quickly as possible, as the ether so speedily exhales.

**Spirit of nitrous ether. L.**

Take of rectified spirit of wine, two pints; nitrous acid, half a pound. Mix them, by pouring in the acid on the spirit, and distil with a gentle heat one pound ten ounces.

**Vinous acid of nitre, commonly called dulcified spirit of nitre. E.**

Take of rectified spirit of wine, three pounds; nitrous acid, one pound. Pour the spirit into a capacious phial, placed in a vessel full of cold water, and add the acid by degrees, constantly agitating them. Let the phial be slightly covered, and laid by for seven days in a cool place; then distil the liquor with the heat of boiling water, into a receiver kept cool with water or snow, till no more spirit comes over.

By allowing the acid and rectified spirit to stand for some time, the union of the two is not only more complete, but the danger also of the vessels giving way to the ebullition and heat consequent on their being mixed, is in a great measure prevented. By fixing the degree of heat to the boiling point, the superabundant acid matter is left in the retort, being too ponderous to be raised by that degree of heat.

Here the operator must take care not to invert the order of mixing the two liquors, by pouring the vinous spirit into the acid; for if he should, a violent effervescence and heat would ensue, and the matter be dispersed in highly noxious red fumes. The most convenient and safe method of performing the mixture seems to be, to put the inflammable spirit into a large glass bottle with a narrow mouth, placed under a chimney, and to pour into it the acid, by means of a glass funnel, in very small quantities at a time; shaking the vessel as soon as the effervescence ensuing upon each addition ceases, before a fresh quantity is put in; by this means the glass will be heated equally, and be prevented from breaking. During the action of the two spirits upon each other, the vessel should be lightly covered; if close stopped, it will burst; and if left entirely open, some of the more valuable parts will exhale. Lemery directs the mixture to be made in an open vessel; by which unscientific procedure, he usually lost, as he himself observes, half his liquor; and we may presume, that the remainder was not the medicine here intended.

Several methods have been contrived for obviating the inconveniences arising from the elastic fluid and violent explosions produced on the mixture of the nitrous acid and rectified spirit of wine: for preparing the nitrous ether they are absolutely necessary, and might perhaps be conveniently used for making the dulcified spirit. The method we judge to be the best, is that employed by Dr Black. On two ounces of the strong acid put into a phial, the doctor pours, slowly and gradually, about an equal quantity of water; which, by being made to trickle down the sides of the phial, floats on the surface of the acid without mixing with it; he then adds, in the same cautious manner, three ounces of highly rectified spirit of wine, Prepared which in its turn floats on the surface of the water. By this means the three fluids are kept separate on account of their different specific gravities, and a stratum of water is interposed between the acid and spirit. The phial is now set in a cool place; the acid gradually ascends, and the spirit descends through the water, this last acting as a boundary to restrain their violent action on each other. By this method a quantity of nitrous ether is formed, without the danger of producing elastic vapours or explosion.

For the preparation of the dulcified spirit, the liquors, when mixed together, should be suffered to rest for some time, as above directed, that the fumes may entirely subside, and the union be in some measure completed. The distillation should be performed with a very slow and well regulated fire; otherwise the vapour will expand with so much force as to burst the vessels. Wilson seems to have experienced the justice of this observation, and hence directs the juncture of the retort and receiver not to be luted, or but slightly: if a tubulated recipient, with a sufficiently long pipe, be used, and the distillation performed with the heat of a water-bath, the vessels may be luted without any danger: this method has likewise another advantage, as it ascertains the time when the operation is finished: examining the distilled spirit every now and then with alkaline salts, as directed above, is sufficiently troublesome; while in a water-bath we may safely draw over all that will rise; for this heat will elevate no more of the acid than what is dulcified by the vinous spirit.

Dulcified spirit of nitre has been long held, and not undeservedly, in great esteem. It quenches thirst, promotes the natural secretions, expels flatulencies, and moderately strengthens the stomach: it may be given from 20 drops to a dram, in any convenient vehicle. Mixed with a small quantity of spirit of hartshorn, the volatile aromatic spirit, or any other alkaline spirit, it proves a mild, yet efficacious, diaphoretic, and often remarkably diuretic; especially in some febrile cases, where such a salutary evacuation is wanted. A small proportion of this spirit added to malt spirits, gives them a flavour approaching to that of French brandy.

**Spirit of ammonia. L.**

Take of proof-spirit, three pints; sal ammoniac, four ounces; pot-ash, six ounces. Mix and distil with a slow fire one pint and an half.

**Vinous spirit of sal ammoniac. E.**

Take of quicklime, 16 ounces; sal ammoniac, eight ounces; rectified spirit of wine, 32 ounces. Having slightly bruised and mixed the quicklime and ammoniacal salt, put them into a glass retort; then add the spirit, and distil in the manner directed for the volatile caustic alkali, till all the spirit has passed over.

This spirit has lately come much into esteem, both as a medicine and a menstruum. It is a solution of volatile salt in rectified spirit of wine; for though proof-spirit be used, its phlegmatic part does not rise in the distillation, and serves only to facilitate the action of the pure spirit upon the ammoniacal salt. Rectified spirit of wine does not dissolve volatile alkaline salts by simple mixture; on the contrary, it precipitates them, as has been already observed, when they are previously dissolved in water; but by the present process, a considerable proportion of the volatile alkali is combined with the spirit. It might perhaps, for some purposes, be more advisable to use with this intention the volatile spirit made with quicklime; for this may be mixed at once with rectified spirit of wine, in any proportion, without the least danger of any separation of the volatile alkali.

The name here employed by the London college, particularly when put in contradiction to the water of ammonia, conveys a clear idea of the article, and is, we think, preferable to that employed by the Edinburgh college.

As a menstruum, the spirit of ammonia is employed to dissolve essential oils, thus forming the volatile aromatic spirit, or compound spirit of ammonia, as it is now called by the London college, which again is employed in making the tinctures of guaiac, valerian, &c.

The chief medical virtues which the spirit of ammonia possesses, when exhibited by itself, are those of the volatile alkali.

Fetid spirit of ammonia.

Take of proof-spirit, six pints; sal ammoniac, one pound; aafetida, four ounces; pot-ash, one pound and a half. Mix them, and draw off by distillation five pints, with a slow fire. L.

Take of vinous spirit of sal ammoniac, eight ounces; aafetida, half an ounce. Digest in a clofe vessel 12 hours; then distil off with the heat of boiling water eight ounces. E.

This spirit, the last formula of which is in our opinion the best, as being most easily prepared without any risk of being injured in the preparation, is designed as an antihysteric, and is undoubtedly a very elegant one. Volatile spirits, impregnated for these purposes with different fetids, have been usually kept in the shops; the ingredient here made choice of, is the best calculated of any for general use, and equivalent in virtue to them all. The spirit is pale when newly distilled, but acquires a considerable tinge in keeping.

Compound spirit of aniseed. L.

Take aniseed, angelica-seed, of each, bruised, half a pound; proof-spirit, one gallon; water, sufficient to prevent an empyreuma. Draw off one gallon by distillation.

This compound spirit is now directed to be prepared by the London college in the same manner as in their former edition. It has no place in the Edinburgh pharmacopoeia; but it may justly be considered as a very elegant aniseed water. The angelica seeds greatly improve the flavour of the anise. It is often employed with advantage, particularly in cases of flatulent cholice; but it has been alleged to be sometimes too frequently used with this intention as a domestic medicine, especially by old ladies: for unless it be prudently and cautiously employed, it may soon be attended with all the pernicious consequences of dram-drinking.

Spirit of caraway. L.

Take of caraway seeds, bruised, half a pound; proof-spirit, one gallon; water, sufficient to prevent an empyreuma. Draw off one gallon.

Spirituous caraway-water. E.

Take of caraway-seeds, half a pound; proof-spirit, nine pounds. Macerate two days in a clofe vessel; then pour on as much water as will prevent an empyreuma, and draw off by distillation nine pounds.

By this process the spirit obtains in great perfection the flavour of the caraway-seeds; and with some it is a cordial not uncommonly in use.

Spirit of cinnamon. L.

Take of bruised cinnamon one pound; proof-spirit, one gallon; water, sufficient to prevent an empyreuma. Draw off one gallon.

Spirituous cinnamon-water. E.

From one pound of cinnamon, nine pounds of spirit are to be drawn off, in the same manner as in the caraway spirit.

This is a very agreeable and useful cordial, but not so strong of the cinnamon as might be expected; for very little of the virtues of the spice arises till after the pure spirituous part has distilled. Hence, in the former editions of the London pharmacopoeia, the distillation was ordered to be protracted till two pints more than here directed were come over. By this means, the whole virtue of the cinnamon was more frugally than judiciously obtained; for the disagreeable flavour of the feints of proof spirits, and the acidulous liquor arising from cinnamon as well as other vegetables when their distillation is long continued, give an ill relish to the whole; at the same time that the oil which was extracted from the spice was by this acid thrown down.

In the Pharmacopoeia Reformata, it is proposed to make this spirit by mixing the simple cinnamon water with somewhat less than an equal quantity of rectified spirit: on shaking them together, the liquor loses its milky hue, soon becomes clear, and more elegant than the water distilled as above: it is equally strong of the cinnamon, and free from the nauseous taint with which the common proof-spirits are impregnated.

Compound spirit of juniper. L.

Take of juniper-berry, bruised, one pound; caraway-seeds, bruised, sweet-fennel seeds, of each one ounce and an half; proof-spirit, one gallon; water, sufficient to prevent an empyreuma. Draw off one gallon.

Compound juniper-water. E.

Take of juniper-berry, well bruised, one pound; seeds of caraway, sweet-fennel, each one ounce and a half; proof-spirit, nine pounds; macerate two days; and having added as much water as will prevent an empyreuma, draw off by distillation nine pounds.

This water, mixed with about an equal quantity of the root of juniper-berry, proves an useful medicine cine in catarrhs, debility of the stomach and intestines, and scarcity of urine. The water by itself is a good cordial and carminative: the service which this and other spirituous water do with these intentions is commonly known; though the ill consequences that follow from their constant use are too little regarded.

**Spirit of lavender.** L.

Take of fresh flowers of lavender, one pound and an half; proof-spirit, one gallon. Draw off by distillation in a water-bath, five pints.

**Simple spirit of lavender.** E.

Take of flowering spikes of lavender, fresh gathered, two pounds; rectified spirit of wine, eight pounds. Draw off by the heat of boiling water seven pounds.

This spirit, when made in perfection, is very grateful and fragrant: It is frequently rubbed on the temples, &c. under the notion of refreshing and comforting the nerves; and it probably operates as a powerful stimulus to their sensible extremities: it is likewise taken internally, to the quantity of a teaspoonful, as a warm cordial.

**Spirit of peppermint.** L.

Take of the herb peppermint, dried, one pound and an half; proof-spirit, one gallon; water, sufficient to prevent an empyreuma. Draw off one gallon.

**Spirituous peppermint-water.** E.

From a pound and a half of these leaves nine pounds of spirit are drawn off, as from the caraway-seeds.

This spirit receives a strong impregnation from the peppermint. It is employed in flatulent colics and similar disorders; and in these it sometimes gives immediate relief: but where it is indicated, there are few cases in which the peppermint-water is not preferable.

**Spirit of spearmint.** L.

Take of spearmint, dried, one pound and an half; proof-spirit, one gallon; water, sufficient to prevent an empyreuma. Draw off one gallon.

This spirit has no place in the Edinburgh pharmacopoeia. It, however, turns out a very elegant one, and preferable, in weakness of the stomach, retching to vomit, and the like, to many more elaborate preparations. Where the disorder is not accompanied with heat or inflammation, half an ounce of this water may be given diluted with some agreeable aqueous liquor: but, as was already observed with regard to the preceding article, there are many cases in which the prudent practitioner will be disposed to give the preference to the simple distilled water.

**Spirit of nutmeg.** L.

Take of bruised nutmegs, two ounces; proof-spirit, one gallon; water, sufficient to prevent an empyreuma. Draw off one gallon.

**Spirituous nutmeg-water.** E.

By two ounces of the nutmeg, well bruised, nine pounds of spirit are impregnated.

This is an agreeable spirituous liquor, highly impregnated with the nutmeg flavour. It was formerly celebrated in nephritic disorders, and when combined with a few hawthorn flowers, it had even the title of nephritic water. At present it is employed only as a cordial liquor, and is not even very frequently in use.

**Spirit of pimento, or allspice.** L.

Take of allspice, bruised, two ounces; proof-spirit, one gallon; water, sufficient to prevent an empyreuma. Draw off one gallon.

**Spirituous Jamaica-pepper water.** E.

By half a pound of pimento nine pounds of spirit are to be impregnated.

This water is far more agreeable than a simple water drawn from the same spice; and had long a place among the cordials of the distiller before it was received into any public pharmacopoeia: but although now adopted both by the London and Edinburgh colleges, it is not very frequently ordered from the shops of the apothecary.

**Spirit of pennyroyal.** L.

Take of the herb pennyroyal, dried, one pound and an half; proof-spirit, one gallon; water sufficient to prevent an empyreuma. Draw off one gallon.

This spirit has no place in the Edinburgh pharmacopoeia. It possesses, however, a considerable share of the flavour of the pennyroyal, and very frequently it is employed as a carminative and antihysteric.

**Compound spirit of horse-radish.** L.

Take of fresh horse-radish root, dried outer-rind of Seville oranges, each two pounds; fresh herb of garden scurvy-grafts, four pounds; bruised nutmegs, one ounce; proof-spirit, two gallons; water, sufficient to prevent an empyreuma. Draw off two gallons.

This spirit has long been considered as an elegant one, and is perhaps as well adapted for the purposes of an antiscorbutic as any thing that can be contrived in this form. It has been alleged, that the horse-radish and scurvy-grafts join very well together, giving a similar flavour, though not a little disagreeable; that the nutmeg suppresses this flavour very successfully, without superadding any of its own; and that to this, orange-peel adds a flavour very agreeable. Arum root had formerly a place in this water, but is here deservedly thrown out; for it gives nothing of its pungency over the helm, notwithstanding what is asserted by some pharmaceutical writers to the contrary. Mustard-feed, though not hitherto employed in these kinds of compositions, would seem to be an excellent ingredient; it gives over the whole of its pungency, and is likewise less perishable than most of the other substances of this class: this feed wants no addition, excepting some aromatic material to furnish an agreeable flavour.

But although this process may furnish an agreeable compound spirit, yet it is much to be doubted, whether it possesses those antiscorbutic powers for which it was once celebrated. And with this intention the Edinburgh college place so little confidence in it, that they have now rejected it from their pharmacopoeia. Spirit of rosemary.

Take of fresh tops of rosemary, one pound and a half; proof-spirit, one gallon. Distil in a water-bath, five pints. L.

Take of flowering tops of rosemary, fresh gathered, two pounds; rectified spirit of wine, eight pounds. Distil in the heat of boiling water till seven pounds come over. E.

A spirit similar to this is generally brought to us from abroad, under the name of Hungary-water.

This spirit is very fragrant, so as to be in common use as a perfume: that brought from abroad is superior in fragrance to such as is generally made among us. In order to prepare it in perfection, the vinous spirit should be extremely pure; the rosemary tops gathered when the flowers are full blown upon them, and committed immediately to distillation, care being taken not to bruise or press them. The best method of managing the distillation, is that which was formerly recommended for the distillation of the more volatile essential oils and simple waters, viz. first to place the spirit in the still, and then set in, above the liquor, either an iron hoop, with a hair-cloth stretched over it, upon which the flowers are to be lightly spread, or rather a basket, supported on three pins, reaching down to the bottom. A gentle heat being applied, just sufficient to raise the spirit, its vapour lightly percolating through the flowers, will imbibe their finer parts, without making that disagreeable alteration, which liquors applied to such tender subjects, in their grosser form, generally do. Probably the superiority of the French Hungary-water, to that prepared among us, is owing to some skilful management of this kind, or to employing a perfectly pure spirit.

In the Würtemberg pharmacopoeia, sage and ginger are added, in the proportion of half a pound of the former, and two ounces of the latter, to four pounds of the rosemary.

But the peculiar agreeable flavour of this water in all probability depends on the rosemary alone.

Carmelite water, or compound balm-water. Dan.

Take of fresh gathered leaves of balm, a pound and a half; the recent yellow rind of lemons, four ounces; nutmeg, coriander, each two ounces; cloves, cinnamon, each one ounce. The ingredients being sliced and bruised, pour upon them rectified spirit of wine, six pounds; balm-water, three pounds. Digest for three days, then draw off six pounds by distillation.

This spirit has been a good deal celebrated, particularly among the French, under the title of Eau de Carmel. Mr Beaumé, in his Éléments de Pharmacie, proposes some improvements on the process. After the spirit added to the ingredients has been drawn off in the heat of a water bath, he orders the distilled liquor to be rectified by a second distillation, drawing off somewhat less than nine-tenths of it. He recommends, that all the aromatic spirits should be prepared in the same manner. When the common spirits of this kind are rubbed on the hands, &c. they leave, after the more volatile parts have exhaled, a disagreeable empty-reumatic smell; and when diluted with water, and taken medicinally, they leave, in like manner, a nauseous flavour in the mouth. To remedy these imperfections, he made many experiments, which showed, that in order to obtain these liquors of the desirable qualities, the spirit must not only be perfectly pure at first, but that the liquor ought also to be rectified after it has been distilled from the subjects. In this rectification, only the more volatile, subtle, aromatic parts of the ingredients arise: there remains behind a white liquor, acrid, bitter, loaded only with the grosser oil, and deprived of all the specific flavour of the subjects. Indeed the very imperfection complained of naturally points out this second distillation as the remedy; for it shows the spirit to contain a grateful and ungrateful matter; the first of which exhales, while the other is left behind. The author says, that when the aqua melissae is prepared as above directed, it has something in it more perfect than any of the odoriferous spirits, whose excellence is cried up, and which have the reputation of being the best.

Aromatic spirituous liquors have in general less smell, when newly distilled, than after they have been kept about six months. M. Beaumé suspects that the preparations of this kind which have been most in vogue, were such as have been thus improved by keeping; and found that the good effects of age might be produced in a short time by means of cold. He plunges quart bottles of the liquor into a mixture of pounded ice and sea-fall; the spirit, after having suffered, for fix or eight hours, the cold thence resulting, proves as grateful as that which has been kept for several years. Simple waters also, after being frozen, prove far more agreeable than they were before, though they are always less so than those which have been drawn with spirit, and exposed to a like degree of cold. This melioration of distilled waters by frost was taken notice of by Geoffroy.

Spirit of scurvy-grafts. Suec.

Take of fresh scurvy-grafts, bruised, 10 pounds; rectified spirit of wine, eight pints. With the heat of a water-bath, distil off four pints.

This spirit is very strong of the scurvy-grafts; and has been given, in those cases where the use of this herb is proper, from 20 to 100 drops. The virtues of scurvy-grafts reside in a very subtile, volatile oil, which arises in distillation both with water and pure spirit; and if the liquors are exposed to the air, soon exhales from both. The spirit, newly distilled, is extremely pungent; but if long kept, even in close vessels, it becomes remarkably less so: but it is not probable, that with such a pungent vehicle we can use a sufficient quantity of the herb to produce any permanent or considerable effect; it has been much recommended as a diuretic in dropsies.

The makers of this spirit have frequently added to the scurvy-grafts a quantity of horse-radish root, and sometimes substituted for it one drawn entirely from the horse-radish: the flavour of these two simples being so much alike, that their distilled spirits are scarcely distinguishable from each other. Here it may be observed, that though arum and draunculus are usually ranked in the same class with the two foregoing vegetables, and considered as similar to them; this process discovers a remarkable difference: while the former yield yield all their pungency in distillation both to water and spirit; the latter give over nothing to either, and yet their virtues are destroyed in the operation.

Orange-peel water. Suec.

Take of recent orange skins, one pound; proof-spirit, three pounds. Draw off two pounds by the heat of a water-bath.

This spirit, which is now rejected from our pharmacopoeias, had formerly a place in them under the title of aqua corticum aurantiorum spirituosa. It is considerably stronger of the orange-peel than the simple water; and it is used as an useful cordial, stomachic, and carminative.

Aromatic spirit. Suec.

Take of the tops of rosemary, a pound and an half; tops of milfoil, thyme, each half a pound; proof-spirit, 16 pounds; macerate for two days, and draw off by distillation eight pounds. If before distillation eight pounds of vinegar be added, it forms the acetated aromatic spirit.

These preparations do not differ materially from the spirit of rosemary or Hungary water; for on the essential oil of the rosemary their medicinal properties may be considered as chiefly depending. They are often employed, particularly for external purposes, and for impregnating the air with their vapours, to destroy the influence of febrile contagions.

Antiseptic spirit. Gen.

Take of spirit of turpentine, an ounce and an half; rectified spirit of wine, half a pound. Distil with a gentle heat. Let the oil swimming above in the receiver be separated from the saturated spirit, which is to be preserved for use.

It has been imagined, that this combination of oil of turpentine with ardent spirit will furnish an effectual solvent for biliary calculi. Hence the origin of the name here given it; but although it may have such an effect when copiously applied to the calculi in a glass vessel; yet this is not to be expected when it is taken into the stomach, and can only reach them in the course of circulation.

Chap. XIX. Decoctions and infusions.

Water, the direct menstruum of gums and salts, extracts readily the gummy and saline parts of vegetables. Its action, however, is not limited to these; the resinous and oily principles being, in most vegetables, so intimately blended with the gummy and saline, as to be in part taken up along with them: some of the resinous cathartics, and most of the aromatic herbs, as well as bitters and astringents, yield to water the greatest part of their smell, taste, and medicinal virtue. Even of the pure essential oils, and odoriferous resins of vegetables, separated from the other principles, water imbibes a part of the flavour; and by the artificial admixture of gummy or saline matter, the whole substance of the oil or resin is made soluble in water.

Of pure salts, water dissolves only certain determinate quantities: by applying heat, it is generally enabled to take up more than it can do in the cold, and this in proportion to the degree of heat; but as the preparation cools, this additional quantity separates, and the water retains no more than it would have dissolved without heat. With gummy substances, on the other hand, it unites unlimitedly, dissolving more and more of them till it loses its fluidity. Heat expedites the action of the water, but cannot enable it to take up more than it would do by allowing it longer time in the cold. The active parts extracted from most vegetables by water, and oils and resins made soluble in water by the artificial admixture of gum, partake of this property of pure gums, being soluble without saturation.

It has been imagined, that vegetables in a fresh state, while their oily, resinous, and other active parts are already blended with a watery fluid, would yield their virtues to water more freely and more plentifully than when their native moisture has been dissipated by drying. Experience, however, shows, that dry vegetables in general give out more than fresh ones, water seeming to have little action upon them in their recent state. If, of two equal quantities of mint, one be infused fresh in water, and the other dried, and then infused in the like quantity of water for the same length of time, the infusion of the dry herb will be remarkably the stronger; and the case appears to be the same in all the vegetables that have been tried.

In all the preparations described in this chapter, it is to be understood that the subjects must be moderately and newly dried, unless when they are expressly ordered to be taken fresh; in which case it is to be judged that their virtues are destroyed or impaired by drying.

The native colours of many vegetables are communicated to water along with their medicinal matter; many impart a colour different from their own; and others, though of a beautiful and deep colour themselves, give scarcely any to the menstruum. Of the first kind are the yellow and red flowers; of the second, the leaves of most plants; of the third, some of the blue flowers, as those of cyanus and larkspur. Acid liquors change the infusions of most flowers, the yellow ones excepted, to a red; and alkalis, both fixed and volatile, to a green.

From animal substances water extracts the gelatinous and nutritious parts; whence glues, jellies, broths, &c.; and along with these, it takes up principles of more activity, as the acrid matter of cantharides. It dissolves also some portion of calcined calcareous earths, both of the animal and of the mineral kingdom, but has no action on any other kind of earthly matter.

The effect of boiling differs from that of infusion in some material particulars. One of the most obvious differences is, that as the essential oils of vegetables, in which their specific odours reside, are volatile in the heat of boiling water, they exhale in the boiling along with the watery steam, and thus are lost to the remaining decoction; whereas both in cold, and sometimes in hot infusions, they are preserved; although in the latter they are by no means perfectly so. Odorous substances, and those in general whose virtues depend on their volatile parts, are therefore unfit for this treatment. The soluble parts of these may, nevertheless, be united in this form with those bodies of a more fixed nature, by boiling the latter till their virt- tues be sufficiently extracted, and then infusing the former in this decoction.

The extraction of the virtue of the subject is usually promoted or accelerated by a boiling heat; but this rule is less general than it is commonly supposed to be. We have already observed, that Peruvian bark gives out its virtue more perfectly by cold infusion than by decoction. In some cases, boiling occasions a manifest diffusion of the principles of the subject; thus, when almonds are triturated with cold water, their oil, blended with the mucilaginous or other soluble matter of the almond, unites with the water into a milky liquor called an emulsion: but on boiling them in water, the oil separates and rises to the surface; and if the most perfect emulsion be made to boil, a like separation happens.

This also appears to take place, though in a less evident manner, in boiling sundry other vegetables; thus tobacco, avarum, and ipecacuanha, lose their active powers by boiling; nor does it appear that this change is effected merely by the discharge of volatile parts. From some late experiments, it has been found, that the distilled water of ipecacuanha was infinitely less emetic than the infusion from which it was distilled, and that the boiling liquor gradually assumes a black colour, indicating some kind of decomposition of parts; the same circumstances probably take place in boiling tobacco, avarum, and perhaps all vegetables whatever, though from their not producing such sensible operations on the living body, they cannot be so clearly discovered as in ipecacuanha, tobacco, or avarum. The experiments we allude to were made by Dr Irving, when a student in the college of Edinburgh; and they gained him the prize given by the Harveian Society of that place, for the best experimental inquiry concerning ipecacuanha.

It is for the above-mentioned reasons that we think many of the infusions should be made with cold water; it is, however, to be acknowledged, that this is not always absolutely necessary, and in extemporaneous practice it may be often very inconvenient; it is, however, proper to point out the advantages to be expected from this more tedious, but much more complete and elegant, method.

Vinegar extracts the virtues of several medicinal substances in tolerable perfection: but at the same time its acidity makes a remarkable alteration in them, or superadds a virtue of a different kind; and hence it is more rarely employed with this intention than purely aqueous or spirituous means. Some drugs, however, for particular purposes, vinegar excellently assists, or coincides with, as squills, garlic, ammoniac, and others; and in many cases where this acid is itself principally depended on, it may be advantageously impregnated with the flavour of certain vegetables; most of the odoriferous flowers impart to their fragrance, together with a fine purplish or red colour; violets, for instance, if fresh parcels of them are infused in vinegar in the cold for a little time, communicate to the liquor a pleasant flavour, and deep purplish red colour. Vinegar, like other acids, added to watery infusions or decoctions, generally precipitates a part of what the water had dissolved.

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**Decoction of marshmallows.**

Take of dried marshmallow roots, four ounces; raisins of the sun, stoned, two ounces; water, seven pounds.

Boil to five pounds; place apart the strained liquor till the feces have subsided, then pour out the clear liquor.

The Edinburgh college have substituted this for the more complicated formula of the Decoction ad Nephriticos of their former pharmacopoeia, and it fully answers the intentions of that preparation: it is intended chiefly as an emollient, to be liberally drank of in nephritic paroxysms; in which cases, by softening and relaxing the parts, it frequently relieves the pain, and procures an easy passage for the fabulous matter. This medicine is now made more simple than before, without any diminution of its virtue, by the rejection of wild carrot seed, retharrow root, figs, linseed, and liquorice. The carrot seeds were indeed unfit for this form, as they give out little of their virtue to watery liquors.

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**Decoction of hartshorn.**

Take of burnt and prepared hartshorn, two ounces; gum arabic, six drams; distilled water, three pints.

Boil, constantly stirring, to two pints, and strain.

This decoction is used as common drink in acute diseases attended with a looseness, and where acrimonious humours abound in the primeæ visæ. The gum is added, in order to render the liquor lightly glutinous, and thus enable it to sustain more of the calx; which is the ingredient on which the colour, but probably not the virtue, of the medicine depends. Calcined hartshorn has no quality from which it seems capable either of constringing and strengthening the vessels, giving a greater degree of consistency to thin fluids, or obtunding acrimonious humours. It blunts and absorbs acid juices; but acrimony and acidity are very different; there are few (perhaps none of the acute) disorders of adults attended with the latter; and few of infants are unaccompanied therewith. Some have proposed flax as an ingredient in these kinds of decoctions; a small quantity of this soft, gelatinous, farinaceous substance would seem to be greatly preferable to the earthy calx. It may be observed, that the water is not enabled by the boiling to dissolve any part of the calx; and that in the decoction, the earth is only diffused in substance through the water, as it would be by agitation.

For these reasons, this formula is now rejected by the Edinburgh college, notwithstanding the reputation in which it was held by Dr Sydenham, and other names of the first eminence. But as an absorbent of a similar nature, the Edinburgh college have introduced the following formula.

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**Chalk julep.**

Take of prepared chalk, one ounce; purest refined sugar, half an ounce; mucilage of gum arabic, two ounces; rub them together; and add by degrees, water, two pounds and a half; spirituous cinnamon water, two ounces. Mix them.

In the former edition of the Edinburgh pharmacopoeia, Take of camomile flowers, one ounce; carvy seeds, Compofition half an ounce; water, five pounds. Boil for a quarter of an hour, and strain.

This decoction is intended to answer the purposes of both the foregoing. It is less loaded with ingredients than either, but not perhaps for that reason the less useful.

It is indeed to be acknowledged, that these impregnations are for the most part unnecessary for the purpose of glysters; and in ordinary cases the weight of the water usually solicits a discharge before these medicines can produce any effect.

As to fomentations, their virtues in our opinion are totally to be ascribed to the influence of the warm water. And when the herbs themselves are applied, they act only as retaining heat and moisture for a longer time.

Decoction of hellebore. L.

Take of the root of white hellebore, powdered, one ounce; distilled water, two pints; rectified spirit of wine, two ounces. Boil the water with the root to one pint; and, the liquor being cold and strained, add to it the spirit.

White hellebore, as we formerly observed, is now very rarely employed internally; and the present formula is entirely intended for external use. Recourse is sometimes had to it with advantage in cutaneous eruptions, particularly in tinea capitis. But where the incrustations are entirely removed, leaving a very tender skin, it is necessary that the decoction should be diluted previous to its employment.

Decoction of barley. L.

Take of pearl-barley, two ounces; distilled water, four pints. The barley being first washed with cold water from the adhering impurities, pour upon it about half a pint of water, and boil the barley a little time. This water being thrown away, add the distilled water, boiling, to the barley; boil it to two pints, and strain.

Compound decoction of barley. L.

Take of the decoction of barley, two pints; raisins, stoned, figs, sliced, each two ounces; liquorice-root, sliced and bruised, half an ounce; distilled water, one pint. Boil to two pints, and strain.

Barley-water. E.

Take of pearl barley, two ounces; water, five pints. First wash the barley from the mealy matter that adheres to it with some cold water; then boil it a little with about half a pint of fresh water, which will acquire a considerable tinge from it. Throw away this tinged water; put the barley into the five pints of boiling water prescribed; and continue the boiling till half the water be wasted.

These liquors are to be drank freely as a diluter, in fevers and other disorders; hence it is of consequence that they should be prepared so as to be as elegant and agreeable as possible; for this reason they are inserted in the pharmacopoeia, and the several circumstances which contribute to their elegance set down; if any one of them be omitted, the beverage will be less grateful. ful. However trivial medicines of this class may appear to be, they are of greater importance in the cure of acute diseases than many more elaborate preparations.

Barley-water, however, is much more frequently prepared by nurses than apothecaries, particularly in its simple state. The compound decoction contains a large proportion of saccharine and mucilaginous matter, and may be employed for the same purposes as the decoction of marshmallows of the Edinburgh pharmacopoeia.

Decoction of the woods. E.

Take of guaiacum saw-dust, three ounces; raisins of the sun, Rome, two ounces; sassafras wood, shaved, liquorice, sliced, each one ounce; water, ten pounds. Boil the guaiacum and raisins with the water, over a gentle fire, to the consumption of one half; adding, towards the end, the sassafras and liquorice. Strain out the liquor; and having suffered it to rest for some time, pour off the clear from the feces without expression.

This decoction is very well contrived; and if its use be duly continued, it will do great service in some cutaneous diseases, in what has been called foulness of the blood and juices, and in some disorders of the breast; particularly in phlegmatic habits. It may be taken by itself to the quantity of a quarter of a pint two or three times a day, or used as an afflatus in a course of mercurial or antimonial alternatives; the patient in either case keeping warm, in order to promote the operation of the medicine. The saw-dust exposes a larger surface to the action of the water than the shavings, directed in the former edition of the pharmacopoeia.

Decoction of sarsaparilla. L.

Take of the root of sarsaparilla, sliced, six ounces; distilled water, eight pints. Macerate for two hours, with an heat of about 195°; then take out the root, and bruise it; return the bruised root to the liquor, and again macerate it for two hours. Then, the liquor being boiled to four pints, press it out, and strain.

This decoction is an article in very common use, particularly in venereal affections. And there can be little doubt, that by this process the medical powers of the sarsaparilla are fully extracted. But it has of late been much questioned, whether this article be in any degree entitled to the high character which was once given of it. Some, as we have already observed, are even disposed to deny its possessing any medical property whatever; but the general opinion is, that it has somewhat of a diaphoretic effect; and this effect is more readily obtained when it is exhibited under the form of decoction than under any other.

Compound decoction of sarsaparilla. L.

Take of the root of sarsaparilla, sliced and bruised, six ounces; bark of the root of sassafras, raisings of guaiacum-wood, liquorice root, bruised, of each one ounce; bark of the root of mezereon, three drams; distilled water, ten pints. Macerate, with a gentle heat, for six hours; then boil it down to five pints, adding, towards the end, the bark of the root of mezereon, and strain the liquor.

This compound decoction is an elegant mode of preparing an article once highly celebrated under the title of the Lisbon diet drink. That formula, for a long time after its first introduction into Britain, was kept a secret; but an account of the method of preparation was at length published in the Physical and Literary Essays of Edinburgh, by Dr Donald Monro. And of the formula there given, which is in many respects an unchemical one, the present may justly be considered as an improvement. Even in its original form, but still more in the present state, there can be no doubt, that it furnishes us with a very useful medicine, particularly in those obstinate ulcers originating from venereal infection, which resist the power of mercury. And it is highly probable, that its good effects principally depend on the impregnation it receives from the mezereon. Perhaps, however, even thus improved, it is more complicated and expensive than is necessary: at least we are inclined to think, that every advantage derived from it may with equal ease and certainty be obtained from impregnating with the mezereon, in the manner here directed, a simple decoction of the guaiacum, bardana, or althaea, without having recourse to several articles, or employing one so expensive as the sarsaparilla.

Decoction of seneka. E.

Take of seneka, or rattlesnake root, one ounce; water, two pounds. Boil to fifteen ounces, and strain.

The virtues of this decoction will be easily understood from those of the root from which it is prepared. The dose, in hydropic cases, and rheumatic, or arthritic complaints, is two ounces, to be repeated three or four times a-day, according to its effect.

Decoction of elm. L.

Take of the fresh inner bark of elm, bruised, four ounces; distilled water, four pints. Boil to two pints, and strain.

It has been chiefly, if not entirely, under this form of decoction, that the elm-bark has been employed for combating those cutaneous eruptions against which it has of late been so highly celebrated. Any experience which we have had of it, however, in actual practice, by no means confirms the very favourable account which some have given of its use.

Mucilage of starch. L.

Take of starch, three drams; distilled water, one pint. Rub the starch, by degrees adding the distilled water; then boil it a little time.

The mucilage thus formed of starch is very useful for answering these purposes where a glutinous substance is required, and in particular it is often successfully employed under the form of glyster.

Mucilage of gum arabic. L.

Take of gum arabic, powdered, four ounces; boiling distilled water, eight ounces. Rub the gum with the water until it be dissolved.

Take of gum arabic, beat into powder, and warm water, each equal weights. Digest, and frequently stir them till the gum be dissolved, then press the solution through linen. It is very necessary to pass the mucilage through linen, in order to free it from pieces of wood and other impurities, which always adhere to the gum; the linen may be placed in a funnel.

Mucilage of gum arabic is very useful in many operations in pharmacy: it is also much used for properties peculiar to those substances of its own class, and of all the gums it seems to be the purest.

**Mucilage of gum tragacanth. E.**

Take of gum tragacanth, powdered, one ounce; hot water, eight ounces. Macerate twenty-four hours; then mix them, by rubbing briskly, that the gum may be dissolved; and press the mucilage through linen cloth.

This gum is more difficultly soluble in water than gum arabic, and seems to be considerably more adhesive; it is therefore fitter for forming troches, and such like purposes. It has been thought to be more peculiarly what has been called a *pectoral*, than the other gums; but this does not seem to be certainly founded. This mucilage is perhaps preferable to the foregoing in those operations in pharmacy where much tenacity is required; as in the suspension of mercury, or other ponderous bodies.

**Mucilage of quince-seed. L.**

Take of seeds of the quince, one dram; distilled water, eight ounces, by measure. Boil with slow fire until the water thickens; then pass it through linen.

This is a pleasant soft mucilage, of a somewhat sweetish taste, and a light agreeable smell: in these respects, and in its easy solubility in water, it differs from the mucilage of gum tragacanth, to which some have supposed it similar: it has another difference, to its disadvantage, being apt to grow mouldy in keeping.

**Compound infusion of gentian. L.**

Take of the root of gentian, one dram; fresh outer-rind of lemons, half an ounce; dried outer rind of Seville oranges, one dram and an half. Boiling water, 12 ounces, by measure. Macerate for an hour, and strain.

**Bitter infusion. E.**

Take of gentian root, half an ounce; dried peel of Seville oranges, one dram; coriander seeds, half a dram; proof-spirit, four ounces; water, one pound. First pour on the spirit, and three hours thereafter add the water; then macerate without heat for a night, and strain.

These formulas do not materially differ. That of the London college is the most expeditious mode of preparation; but that of the Edinburgh college possesses other advantages, which are in our opinion more than sufficient to outweigh that circumstance.

In the former edition of the Edinburgh pharmacopoeia the water was directed to be boiling: this was at least unnecessary, and was probably liable to the objections observed against decoctions. The proof-spirit is also a useful addition to the bitter infusion, as it now stands in the Edinburgh pharmacopoeia: besides that it assists in extracting the resinous parts, and preserving the infusion from fermentation, it communicates an agreeable pungency to the liquor. To answer in some measure these intentions, it was formerly directed to add to the filtrated liquor a quantity of aromatic water. This was certainly a piece of very bad pharmacy; for, besides that the spirit in this preparation, when diluted with the water of the infusion, was now no longer able to retain the suspended matter, it would also dilute the infusion to part with its proper extractive matter; and in this way the resinous matter of the aromatic water, and the gummy parts of the bitter infusion, would both in some degree separate to the bottom of the vessel. By the formula now laid down, the infusion contains the different principles of the ingredients in a manner more nearly approaching to their natural and entire state.

**Simple infusion of senna. I.**

Take of senna, an ounce and a half; ginger, powdered, one dram; boiling distilled water, one pint. Macerate them for an hour in a covered vessel; and the liquor being cold, strain it.

This, although a simple, is a very elegant infusion of senna, the ginger acting as an useful corrigent. But if the senna were employed to the quantity of a dram and an half or two drams only, with the same menstruum, in place of the quantity here ordered, it would be a no less useful medicine, and might be employed for one dose, as it is best when fresh. Of the present infusion, an ounce or two is a sufficient dose.

**Tartarized infusion of senna. L.**

Take of senna, one ounce and a half; coriander seeds, bruised, half an ounce; crystals of tartar, two drams; distilled water, one pint. Dissolve the crystals of tartar by boiling in the water; then pour the water, as yet boiling, on the senna and seeds. Macerate for an hour in a covered vessel, and strain when cold.

In the last edition of the London pharmacopoeia this had the name of *infusum sennae commune*.

Formerly an alkaline salt was used in the infusion of senna instead of the acid one here directed. The first was supposed to promote the operation of the medicine, by superadding a degree of purgative virtue of its own, and by enabling the water to extract somewhat more from the capital ingredient than it would be capable of doing by itself; while acids were alleged to have rather a contrary effect. Experience, however, has sufficiently shown, that alkaline salts increase the offensiveness of the senna, while crystals of tartar considerably improve the colour of the infusion, and likewise render the taste to some persons less disagreeable. Soluble tartar should seem a good ingredient to these kinds of compositions, as it not only improves the taste, but promotes the purgative virtue of the medicine: this addition also renders the infusion less apt to gripe, or occasion flatulencies.

**Infusion of tamarinds with senna. E.**

Take of tamarinds, six drams; crystals of tartar, senna, each one dram; coriander seeds, half a dram; brown sugarcandy, half an ounce; boiling water, eight ounces. Macerate in a close earthen vessel which has not been vitrified with lead; stir the liquor now and and then, and after it has stood four hours strain it. It may also be made with double, triple, &c. the quantity of fenna.

Both this and the former infusions might be made with cold water. By this means the aromatic quality of the coriander seeds would probably be extracted in a more perfect state; but the crystals of tartar are so difficultly soluble in cold water, that for extemporaneous use it is in some measure necessary to prepare them in the manner here directed. It is not indeed probable, that when such soluble matters as acids and sugar are presented to water, the water shall be able to extract such a quantity of the finer volatile part of aromatics as to afford any considerable flavour to the liquor. Where an aromatic is required, we would therefore propose, that some agreeable aromatic water should be mixed with the liquor immediately before swallowing it; or that a quantity of aromatic oil should be incorporated with the cold infusion by means of gum, or a part of the sugar which might be reserved for that purpose. It is a very necessary caution not to make this infusion in vessels glazed with lead, otherwise the acid might corrode the lead, and communicate its poisonous effects to the infusion.

Both these infusions are mild and useful purges; the latter in particular is excellently suited for delicate stomachs, at the same time that it is very much calculated for febrile and other acute diseases. It is observable, that sugar added to neutral salts rather increases than diminishes their nauseousness; but when used along with an acid, such as tamarinds, or a salt wherein the acid predominates, as in crystals of tartar, it is found very much to improve their taste. The acid in this infusion, or rather the combination of acid and sweet, are found to cover the taste of the fenna very effectually: the aromatic serves also the same purpose, but would perhaps be better applied in the way above proposed.

Infusion of the rose. L.

Take of red rose-buds, the heads being cut off, half an ounce; vitriolic acid, diluted, three drams; boiling distilled water, two pints and a half; double-refined sugar, one ounce and a half. To the water, first poured on the petals in a glass vessel, add the diluted vitriolic acid, and macerate for half an hour. Strain the liquor when cold, and add the sugar.

Infusion, commonly called tincture of roses. E.

Take of red roses, dried, one ounce; boiling water, five pounds; vitriolic acid, one dram; white sugar, two ounces. Macerate the roses with the boiling water in an unglazed vessel four hours; then having poured on the acid, strain the liquor, and add the sugar.

Some have directed the vitriolic acid to be dropped upon the roses before the water is put to them: but this method is certainly faulty; for such of the roses as this caustic liquor falls on undiluted will be burnt up by it, and have their texture destroyed. Others have made an infusion of the roses in water first, and then added the acid, from an apprehension, that if this acid be added to the water, it would weaken its power as a menstruum; but whatever the acid spirit will hinder the water from extracting, it must precipitate if added afterwards; though, in this preparation, the Preparative acid bears so small a proportion to the water, and that its effects in this respect will be very little; and it appears to be of little consequence which of the two ways be followed, only that by the above formula the vessels are exposed a shorter time to the action of the acid. The infusion should be made in a glass or stone-ware vessel, rather than a glazed earthen one; for the acid will be apt to corrode the glazing of the latter.

This infusion is of an elegant red colour, and makes a very grateful addition to juleps in hemorrhagies, and in all cases which require mild coolers and subastringents. It is sometimes taken with bouches or electuaries of the bark, and likewise makes a good gargle. But although in our pharmacopoeias it has its name from the roses, yet its virtues are to be ascribed chiefly, or perhaps solely, to the vitriolic acid.

Infusion of rhubarb. E.

Take of rhubarb, half an ounce; boiling water, eight ounces; spirituous cinnamon water, one ounce. Macerate the rhubarb in a glass vessel with the boiling water for a night; then having added the cinnamon water, strain the liquor.

In this infusion cold water might perhaps be employed with advantage; we also object to the spirituous cinnamon-water on the same grounds as we did before to the aromatic water in the bitter infusion of the former edition of the Edinburgh pharmacopoeia. This, however, appears to be one of the best preparations of rhubarb when designed as a purgative; water extracting its virtue more effectually than either vinous or spirituous menstrua. In this respect rhubarb differs from most of the other vegetable cathartics; and we think the London college might have given it a place in their pharmacopoeia as well as the wine or tincture of rhubarb.

Lime-water.

Take of quicklime, half a pound; boiling distilled water, twelve pints. Mix, and set it aside in a covered vessel for an hour; then pour off the liquor, which keep in a close vessel. L.

Take half a pound of fresh-burnt quicklime, put it into an earthen vessel, and gradually sprinkle on it four ounces of water, keeping the vessel shut while the lime grows hot and falls into powder; then pour on it twelve pounds of water, and mix the lime thoroughly with the water by stirring. After the lime has subsided renew the stirring; and let this be done about ten times, always keeping the vessel shut (during the ebullition), that the access of the air may be the more effectually prevented. Lastly, let the water be filtered through paper placed in a funnel close shut at its top; and it must be kept in very close vessels. E.

The reason of adding the water by degrees to the lime is, that when poured on at once it reduces the external part to a kind of muddy substance, or soft paste, which in some measure defends the internal part from being acted on by the water. It does not appear that the different proportions of water in the two above prescriptions occasion any sensible difference in the strength of the product: the quicklime is far from yielding all its soluble parts to either proportion; the remainder remainder giving a strong impregnation to many fresh quantities of water, though not so strong as to the first. The caution of keeping the water in close-stopped vessels ought to be strictly attended to; for in open ones the calcareous matter dissolved in the liquor soon begins to separate, and forms a white crust on the surface. This crust is not of a saline nature, as some have imagined; but an insipid earth, no longer miscible with watery liquors. The theory of the production of this earth will be easily understood from what we have said on the article Fixed Air. The separation first takes place at the surface, as being the part immediately applied to the common air. As long as the crust remains entire, the closeness of its texture so excludes the air, that the rest of the matter still remains impregnated with lime; but when this pellicle is broken by any means, it soon sinks to the bottom, and exposes a new surface for the separation of the lime. In this way a succession of crusts and precipitations are formed, till the whole of the once caustic and soluble quicklime is now found at the bottom of the vessel in the state of a mild insoluble earth, leaving the water perfectly insipid.

The formation of these crusts, and their successive precipitations, are owing to the absorption of fixed air, or aerial acid, from the atmosphere; and the mild insoluble state of these precipitations is also owing to the same cause.

The distilled water recommended by the London college is certainly preferable to common fountain water; the purity of which can rarely be depended on.

Lime-water has been thought of great service in scrofulous complaints; but perhaps on no very good foundation. It has also been used both internally and externally for various affections of the skin. It seems to be very considerably astringent, and has been useful in some kinds of alvine fluxes, in diabetes, leucorrhoea, and in sundry other disorders proceeding from a laxity or debility of the solids.

Its more common use is in affections of the stomach accompanied with acidity and flatulence. For which last complaint, the mild or aerated earths are less proper, on account of the separation of air on their meeting with an acid in the stomach. Lime-water is also capable of dissolving mucus; and may therefore be used where a redundancy of the intestinal mucus affords a nidus for worms, or gives rise to other complaints. It has also been found, that lime-water injected into the anus immediately kills ascariads. The lithotriptic powers of lime-water seem at present to be much doubted. Lime-water is given in doses proportioned to the nature of the complaints; in some cases, as in diabetes, it may be given in divided portions to the extent of two quarts a-day. It is used externally for washing what are called foul or ill-conditioned ulcers; it is also injected into the vagina and other parts affected with preternatural discharges from laxity.

The use of lime-water in scurvy is very doubtful.

**Vinegar of squills.**

Take of squills, dried, one pound; vinegar, six pints; proof-spirit, half a pint. Macerate the squills in the vinegar, with a gentle heat, in a glass vessel, for four-and-twenty hours; then press out the liquor, and set it by that the feces may subside: lastly, pour off the liquor, and add to it the spirit.

**Take of dried root of squills, two ounces; distilled vinegar, two pounds and a half; rectified spirit of wine, three ounces. Macerate the squills with the vinegar eight days; then press out the vinegar, to which add the spirit; and when the feces have subsided, pour off the clear liquor.**

Vinegar of squills is a medicine of great antiquity; we find in a treatise attributed to Galen, an account of its preparation, and of many particular virtues then ascribed to it. It is a very powerful stimulant, aperient, and what is called an attenuant of tenacious juices; and hence it is frequently used, with great success, in disorders of the breast occasioned by a load of thick phlegm, and for promoting urine in hydroptic cases. The dose of this medicine is from a dram to half an ounce: where crudities abound in the first passages, it may be given at first in a larger dose, to evacuate them by vomiting. It is most conveniently exhibited along with cinnamon, or other agreeable aromatic waters, which prevent the nausea it would otherwise, even in small doses, be apt to occasion.

**Aromatic vinegar. Suec.**

Take of tops of rosemary, leaves of sage, each four ounces; flowers of lavender, two ounces; cloves two drams; vinegar, eight pounds. Macerate for four days, express the liquor, and strain it.

This may be considered as an elegant improvement of what had formerly a place in the foreign pharmacopoeias, under the title of acetum prophylacticum, which contained not only the present articles, but also a confused tartar of others, as wormwood, rue, garlic, cinnamon, &c.

It is said, that during the plague at Marseilles, four persons, by the use of the acetum prophylacticum as a preservative, attended, unhurt, multitudes of those who were infected: that under colour of those services, they robbed both the sick and the dead: and that one of them being afterwards apprehended, saved himself from the gallows by discovering the remedy. The preparation was hence called Vinaigre des quatre voleurs; "The vinegar of the four thieves." It is not to be doubted that vinegar, impregnated with antiseptic vegetables, will contribute greatly to prevent the effects of contagious air. And in the present aromatic vinegar we have a stronger and better impregnation, than from the numerous articles which were before employed. We are far, however, from imagining that it will be able to counteract the contagion of the plague: but it may on different occasions be more powerful than vinegar in its simple state, for impregnating with antiseptic vapours the chambers of the sick.

**Vinegar of roses. Suec.**

Take of the flowers of red roses dried, any quantity; add to them twelve times their weight of vinegar. Macerate for four days, and strain through paper.

This has been chiefly used for embrocating the head and temples in some kinds of headache, &c. in which it has now and then been of service. It has also been used for certain cases of ophthalmia. But before it can can be applied to the eyes, it will in general require to be diluted with water.

**Vinegar of lead. Succ.**

Take of litharge, triturated, half a pound; vinegar, two pounds. Digest them together, frequently stirring the mixture with a wooden rod, till the colour of blue paper be not changed by the vinegar; preserve for use the clear liquor which is above the sediment.

This liquor is of the same nature with solutions of sugar of lead, or acetated ceruse, as it is now called. It is only used externally against cutaneous eruptions, redness, inflammations, &c. But even in these cases some think it is not void of danger: and it is alleged, that there are examples of its continued use having occasioned sundry ill consequences. Of this, however, we are very doubtful. But by means of the acetated ceruse every purpose to be answered by this may be accomplished. This liquor differs only in the proportions from the water of acetated litharge of the London pharmacopoeia.

**Vinegar of colchicum. Ros.**

Take of the recent root of colchicum cut into slices, one ounce; vinegar, one pound. Macerate with a gentle heat for two days: then strain after slight expression.

Although in our pharmacopoeias a place be given to the oxymel and syrup of colchicum, both of which are formed from the vinegar, yet the vinegar itself is not directed to be kept in its separate state: under this form, however, it may often be employed with advantage.

**Infusion of Peruvian bark. Succ.**

Take of Peruvian bark, bruised, an ounce and a half; river water, boiling, a pound and a half. Digest for two hours, shaking the vessel frequently; then strain the liquor with expression.

The Peruvian bark, as we have already had occasion to observe, gives out its medical properties to water not less readily in the way of infusion than of decoction. And in the former, the extractive matter is even more in a state of solution. An infusion, however, not only more elegant, but stronger than the present, might be obtained, from employing cold instead of boiling water, and from continuing the maceration for a greater length of time. But in whatever manner it be formed, an infusion will often sit on the stomach, when the bark either in substance or decoction cannot be retained.

**Tar-water. Succ.**

Take of tar two pounds; water, one gallon. Stir them strongly together with a wooden rod; and after standing to settle for twelve hours, pour off the water for use.

Tar-water has lately been recommended to the world as a certain and safe medicine in almost all diseases; a slow yet effectual alternative in cachexies, fevers, chlorotic, hysterical, hypochondriacal, and other chronic complaints; and a sudden remedy in acute distempers which demand immediate relief, as pleuritis, peripneumonies, the small-pox; and all kinds of fevers in general. The medicine, though certainly far inferior to the character that has been given of it, is doubtless in many cases of considerable utility: it sensibly raises the pulse; and occasions some considerable evacuation, generally by perspiration or urine, though sometimes by stool or vomit. Hence it is supposed to act by increasing the vis vitae, and enabling nature to expel the morbid humours.

We shall here insert, from the first public recommendor of this liquor (Bishop Berkeley), some observations on the manner of using it. "Tar-water, when right, is not paler than French, nor deeper coloured than Spanish, white wine, and full as clear; if there be not a spirit very sensibly perceived, in drinking, you may conclude the tar-water is not good. It may be drank either cold or warm. In colics, I take it to be best warm. As to the quantity, in common chronical indispositions, a pint a-day may suffice, taken on an empty stomach, at two or four times, viz. night and morning, and about two hours after dinner and breakfast: more may be taken by stronger stomachs. But those who labour under great and inveterate maladies, must drink a greater quantity, at least a quart every twenty-four hours. All of this class must have much patience and perseverance in the use of this, as well as of all other medicines, which, though sure, must yet in the nature of things be slow in the cure of inveterate chronical disorders. In acute cases, fevers of all kinds, it must be drank in bed warm, and in great quantity (the fever still enabling the patient to drink), perhaps a pint every hour, which I have known to work surprising cures. But it works too quick, and gives such spirits, that the patients often think themselves cur'd before the fever has quite left them."

Notwithstanding these encomiums, tar-water seems to be fast losing its reputation. It is not probable that water can take up any of the more active principles of the tar; and it would perhaps be more convenient to separate its acid by distillation, and mix it with water occasionally: for it is pretty certain, that the water can only take up the acid of the tar, perhaps charged with a very small quantity of oily matter in the state of an acid soap.

**Decoction of catechu. Gen.**

Take of catechu, three drams; spring-water, two pounds: boil it to one pound; and add to the strained liquor, of syrup of quinces, three ounces.

This decoction may be considered as nearly similar to the decoction japonicum, and decoction terre japonicae of the former editions of our pharmacopoeia: and like these it will be found a very agreeable and useful medicine in fluxes that are not critical or symptomatic, and in a weak lax state of the intestines. A spoonful or two may be taken every hour, or oftener: thus managed, it produces much better effects than if larger doses are given at once. But for extracting the powers of the catechu, boiling is not requisite. By simple infusion in warm water, all its active parts are readily and completely dissolved. It may in this manner also be readily united with cinnamon or other aromatics. And an infusum japonicum is, we think, a formula justly entitled to a place in our pharmacopoeias. The original intention of medicated wines was, that medicines, which were to be continued for a length of time, might be taken in the most familiar and agreeable form; by this means a course of remedies was complied with, notwithstanding the repugnance and aversion which the sick often manifest to those directly furnished from the shops; and hence the inferior sort of people had their medicated ales. Nevertheless, as vinous liquors excellently extract the virtues of several simples, and are not ill fitted for keeping, they have been employed as officinal menstrua also; and substances of the greatest efficacy are trusted in this form. As compounds of water and inflammable spirit, they take up such parts of vegetables and animals as are soluble in those liquors; though most of them abound at the same time with a mucilaginous or viscous substance, which renders them less effectual menstrua than purer mixtures of water and spirit. They contain likewise a subtile acid, which somewhat further obstructs their action on certain vegetable and animal matters; but enables them, in proportion to its quantity, to dissolve some bodies of the metallic kind, and thus impregnate themselves with the corroborating virtues of steel, the alternative and emetic powers of antimony, and the noxious qualities of lead.

To all the medicated wines, after they have been strained, you may add about one-twentieth their quantity of proof spirit, to preserve them from fermentation. They may be conveniently kept in the same kind of glass bottles that wines generally are for common uses, which should likewise be corked with the same care.

**Wine of aloes. L.**

Take of focotorine aloes, eight ounces; white canella, commonly called winter's bark, two ounces; Spanish white wine, six pints; proof-spirit, two pints. Powder the aloes and white canella separately; when mixed, pour on them the wine and spirit; afterwards digest for fourteen days, now and then shaking them; lastly, strain. It will not be amiss to mix white sand, cleansed from impurities, with the powder, in order to prevent the moistened aloes from getting into lumps.

**Aloetic wine, or sacred tincture. E.**

Take of focotorine aloes, one ounce; lesser cardamom seeds, ginger, each one dram; Spanish white wine, two pounds. Digest for seven days, stirring now and then, and afterwards strain.

This medicine has long been in great esteem, not only as a cathartic, but likewise as a stimulus; the wine dissolving all that part of the aloes in which these qualities reside, a portion only of the less active resinous matter being left. The aromatic ingredients are added to warm the medicine, and somewhat alleviate the ill flavour of the aloes: white canella, or cloves, are said, among numerous materials that have been tried, to answer this end the most successfully; hence the introduction of the former of these into the formula of the London college.

**Bitter wine. E.**

Take of root of gentian, half an ounce; Peruvian bark, one ounce; Seville orange-peel, dried, two drams; white canella, one dram; proof spirit, four ounces; Spanish white wine, two pounds and a half. First pour on the spirit, after twenty-four hours add the wine; then macerate for three days, and strain.

This wine is intended to supply the place of the stomachic tincture, as it was formerly called. The wine is a menstruum fully capable of extracting the active powers of the different ingredients; and it supplies us with a very useful and elegant stomachic medicine, answering the purposes intended much better than the celebrated elixir of Van Helmont, and other unchemical and uncertain preparations, which had formerly a place in our pharmacopoeias.

**Wine of antimony. L.**

Take of vitrified antimony, powdered, one ounce; Spanish white wine, a pint and an half. Digest for twelve days, frequently shaking the vessel, and filter the wine through paper.

**Antimonial wine. E.**

Take of glass of antimony, finely powdered, one ounce; Spanish white wine, fifteen ounces. Macerate for three days, stirring them now and then, and afterwards strain the liquor through paper.

However carefully the settling and decantation are performed, the filtration of the wine through paper appears to be necessary, lest some of the finer parts of the glass should chance to remain suspended in substance. It is not here, as in most other wines and tinctures, where the matter left undissolved by the menstruum is of little consequence; the antimonial glass, after the action of the wine, continues as virulent as ever, and capable of impregnating fresh parcels of the liquor as strongly as the first, and this, in appearance, inexhaustibly. After thirty repeated infusions, it has been found scarce sensibly diminished in weight.

The antimonial wine possesses the whole virtues of that mineral, and may be so dosed and managed as to perform all that can be effected by any antimonial preparation; with this advantage, that as the active part of the antimony is here already dissolved and rendered miscible with the animal fluids, its operation is more certain. Given from ten to fifty or sixty drops, it generally acts as an alternative and diaphoretic; in larger doses, as a diuretic and cathartic; while three or four drams prove for the most part violently emetic. It has been chiefly used with this last intention, in some maniacal and apoplectic cases; and hence it gained the name of emetic wine.

The quantity of the reguline part must, however, vary according to the proportions of the acid matter in different wines, and the operation of the medicine must be thereby less certain in degree; the vitrum is preferable to the crocus for making this preparation. See the different preparations of Antimony.

Wine of tartarized antimony. L.

Take of tartarized antimony, two scruples; boiling distilled water, two ounces; Spanish white wine, eight ounces; dissolve the tartarized antimony in the boiling distilled water, and add the wine.

Wine of antimonial tartar. E.

Take of antimonial tartar, commonly called emetic tartar, twenty four grains; and dissolve it in a pound of Spanish white wine.

Watery solutions of emetic tartar, on standing, precipitate a part which is less completely in a saline state; by this means, and especially if the solution be not shaken before using it, the dose of that medicine is somewhat ambiguous: in the above formula, the acid matter of the wine increases the saline state of the antimony, and therefore its solubility, whereby the operation of the medicine is more certain, and in many cases more powerful. From the certainty of its effects, this preparation might be very convenient in large hospitals or armies, where great numbers of the sick, and inaccurate nursing, frequently occasion an uncertain or dangerous practice.

In the formula employed by the Edinburgh college, each ounce of the wine contains two grains of the tar- tarized antimony; but in that of the London college, each ounce of the menstruum contains four grains: hence, while an ounce of the one may be employed for exciting full vomiting, the same quantity of the other would be too strong a dose. It is much to be regretted, that, in articles of this active nature, the proportions employed by the two colleges should differ so considerably: and it would perhaps have been better, had the London college adopted the proportions employed by that of Edinburgh, as they have followed them in adopting this formula.

Wine of iron. L.

Take of filings of iron, four ounces; Spanish white wine, four pints. Digest for a month, often shaking the vessel, and then strain.

This formula of the London pharmacopoeia is now not only simplified, but improved, when compared with their former vinum chalybeatum: for the cinnamon and other articles which were then conjoined with the iron, were certainly rather prejudicial than otherwise; but at the same time, Rhenish wine, formerly employed, is perhaps to be considered as a better menstruum than the Spanish wine now directed. It may still, however, be justly considered as a good chalybeate; and we think the Edinburgh college have done wrong in rejecting the formula from their pharmacopoeia.

By the London college it was formerly prepared by maceration, without heat; now, however, they direct digestion for the space of a month. Some have objected to the use of heat, that it impregnated the wine more strongly with the metal, and thus rendered it more unpleasant to the taste: but if this was the only inconvenience, the remedy would be easy, diluting it with more wine. Heat has another effect, much less desirable, and which art cannot remedy; making a disagreeable alteration in the quality of the wine itself: hence it is necessary that it should be very moderate.

Steel-wine is a very useful preparation of this metal, and frequently exhibited in chlorotic and other indispositions where chalybeates are proper. Boerhaave recommends it as one of the noblest medicines he was acquainted with for promoting that power in the body by which blood is made, when weakened by a bare debility of the over-relaxed solids, and an indolent, cold, aqueous indisposition of the juices: for in this case, says he, no virtue of any vegetable or animal substance, no diet, nor regimen, can effect that which is effected by iron: but it proves hurtful where the vital powers are already too strong, whether this proceeds from the fluids or the solids. The dose is from a dram to half an ounce; which may be repeated two or three times a day.

Some direct solutions of iron, made in wine or other vegetable acids, to be evaporated to the consistence of an extract, under the title of extratum martis. These preparations have no advantage, in point of virtue, above the common chalybeates: though in some forms, that of pills in particular, they may be rather more commodiously exhibited than most of the officinal chalybeates of equal efficacy. They may be made into pills by themselves, and are tenacious enough to reduce other substances into that form.

Wine of ipecacuanha. L.

Take of the root of ipecacuanha, bruised, two ounces; Spanish white wine, two pints. Digest for ten days, and strain.

Wine, or tincture, of ipecacuanha. E.

Take of ipecacuanha, in powder, one ounce; Spanish white wine, fifteen ounces. After three days maceration, let the tincture be filtrated for use.

Both these wines are very mild and safe emetics, and equally serviceable in dysenteries also with the ipecacuanha in substance; this root yielding nearly all its virtues to the Spanish white wine here ordered, as it does a good share of them even to aqueous liquors. The common dose is an ounce, more or less, according to the age and strength of the patient. The college of Edinburgh added formerly a scruple of cochineal, which imparts a fine red colour to the liquor: this article is now omitted, on a complaint that the red colour of the matters evacuated sometimes alarmed the patient, as if it proceeded from a discharge of blood.

Wine of miliepedes. E.

Take of live miliepedes, bruised, one ounce; Rhenish wine, eight ounces. Infuse them together for twelve hours, and afterwards press the liquor through a strainer.

This wine has been commended as an admirable cleanser of all the viscera, yielding to nothing in the jaundice and obstructions of the kidneys or urinary passages. passages, of excellent service in almost all chronical di- stempers, even in scrofulous and strumous swellings, and in defluxions of rheum upon the eyes. But those who expected these extraordinary virtues from it have often been deceived; and at present there are few who have any great dependence on it; and hence it is omit- ted by the London college, probably without any loss. It is directed to be given from half an ounce to two ounces.

Wine of rhubarb. L.

Take of sliced rhubarb, two ounces and an half; lesser cardamom-seeds, bruised and hulked, half an ounce; faftion, two drams; Spanish white wine, two pints; proof-spirit, eight ounces. Digest for ten days, and strain.

Rhubarb-wine. E.

Take of rhubarb, two ounces; white canella, one dram; proof-spirit, two ounces; Spanish white wine, fif- teen ounces. Macerate for seven days, and strain. By afflicting the solvent power of the menstruum, the proof-spirit in the above formula is a very useful addition. This is a warm, cordial, laxative medicine. It is used chiefly in weaknesses of the stomach and bowels, and some kinds of loofenefices, for evacuating the of- fending matter, and strengthening the tone of the vis- cera. It may be given from half a spoonful to three or four spoonfuls or more, according to the circum- stances of the disorder, and the purpose it is intended to answer.

Tobacco-wine.

Take of the dried leaves of the best Virginian tobacco, one ounce; Spanish white wine, one pound. Ma- cerate for four days, and then strain the liquor. We have already, under the article NICOTIANA, offered some observations on its late introduction into practice by Dr Fowler, as a very useful remedy in the cure of dropsies and dysuries. From his trea- tise on that subject the present formula is taken; and we may observe, that while in practice we have frequently experienced from the tobacco those good effects for which Dr Fowler recommends it, we are inclined to give the present formula the preference to every other which he has proposed. It seems to extract more fully the active principles of the tobacco than either water or spirit taken separately. For fur- ther observations on the medical virtues of tobacco, see the article NICOTIANA.

Squill-wine. Succ.

Take of dried squill, sliced, one ounce; ginger, one dram; French white wine, two pounds. Macerate for three days, and then strain. By the wine employed as a menstruum, the active properties of the squills may be readily extracted; and in some cases at least the present formula may justly be considered as entitled to a preference over either the vinegar or oxymel of squills, which have a place in our pharmacopoeias. The ginger here added to the squills operates as an useful corrigent; and on this account the present formula is preferable to the squill-wine of some other pharmacopoeias, where the squills alone are used; For it is chiefly used in those cases where it is intended that the squills should exert their effects, not on the alimentary canal, but on the kidneys or other excretories.

Zedoary wine. Dan.

Take of the root of zedoary, gently bruised, two pounds; spirit of wine, eight pounds. Let them be macerated for a month; then add spring water, eight pounds. Distil from thence twelve pounds. Though this formula has the name of a wine, yet it is in reality a distilled spirit, nothing from the ze- doary but a portion of its essential oil being united with the ardent spirit; and we are inclined to think, that the active powers of this article, both as depend- ing on aroma and bitterness, might be better obtained by a simple infusion in Spanish white wine.

CHAP. XXI. Tinctures.

RECTIFIED spirit of wine is the direct menstruum of the resins and essential oils of vegetables, and totally extracts these active principles from sundry vegetable matters, which yield them to water either not at all, or only in part. It dissolves likewise the sweet saccha- rine matter of vegetables; and generally those parts of animal bodies in which their peculiar smell and taste reside. The virtues of many vegetables are extracted almost equally by water and rectified spirit; but in the wa- tery and spirituous tinctures of them there is this dif- ference, that the active parts in the watery extractions are blended with a large proportion of inert gummy matter, on which their solubility in this menstruum in a great measure depends, while rectified spirit extracts them almost pure from gum. Hence, when the spiri- tuous tinctures are mixed with watery liquors, a part of what the spirit had taken up from the subject gene- rally separates and subsides, on account of its having been freed from that matter which, being blended with it in the original vegetable, made it soluble in water. This, however, is not universal; for the ac- tive parts of some vegetables, when extracted by recti- fied spirit, are not precipitated by water, being almost equally soluble in both menstrua. Rectified spirit may be tinged by vegetables of all colours except blue: the leaves of plants in general, which give out but little of their natural colour to wa- tery liquors, communicate to spirit the whole of their green tincture, which for the most part proves elegant, though not very durable. Fixed alkaline salts deepen the colour of spirituous tinctures; and hence they have been supposed to pro- mote the dissolving power of the menstruum, though this does not appear from experience: in the trials that have been made to determine this affair, no more was found to be taken up in the deep-coloured tinctures than in the paler ones, and often not so much: if the alkali be added after the extraction of the tincture, it will heighten the colour as much as when mixed with the ingredients at first. Nor does the addition of these salts make tinctures useless only, but likewise preju- dicial, as they in general injure the flavour of aro- matics, and superadd a quality, sometimes contrary to the intention of the medicine. Volatile alkaline salts, in many cases, promote the action of the spirits. A- cids generally weaken it; unless when the acid has been previously combined with the vinous spirit into a compound of new qualities, called dulcified spirit.

Tincture of wormwood. E.

Take of the flowering tops of wormwood, properly dried, four ounces; rectified spirit of wine, two pounds. Macerate for two days; then press out the spirit, and pour it on two ounces of wormwood. Macerate again for four days; then press the tincture through a cloth, and afterwards strain it through paper.

The aromatic parts of wormwood are more especially found in the flowering tops, and its bitterness in the leaves: but as the latter are replete with a mucilaginous matter, which might impede the action of the menstruum on the aromatic parts in this very elegant formula, the flowering tops are infused first, and their tincture made to extract the bitter parts of the leaves and stalks. This preparation may therefore be considered as containing the whole virtues of the plant.

In the tincture of wormwood we have one of the strongest of the vegetable bitters. It is sometimes used as an anthelmintic, and still more frequently in stomach ailments: But to most people it is a very disagreeable medicine.

Tincture of aloes. L.

Take of socotrine aloes, powdered, half an ounce; extract of liquorice, an ounce and an half; distilled water, proof-spirit, of each eight ounces. Digest in a sand-bath, now and then shaking the vessel, until the extract be dissolved, and then strain.

In this simple tincture all the active parts of the aloes, whether of a gummy or resinous nature, are suspended in the menstruum. The extract of liquorice serves both to promote the suspension and to cover the taste of the aloes; and in these cases where we wish for the operation of the aloes alone, without the aid either of an adjuvant or corrigens, this is perhaps one of the best formulae under which aloes can be exhibited in a fluid state.

Compound tincture of aloes. L.

Take of tincture of myrrh, two pints; saffron, socotrine aloes, of each three ounces. Digest for eight days, and strain.

Elixir of aloes, commonly called elixir proprietatis. E.

Take of myrrh in powder, two ounces; socotrine aloes, an ounce and a half; English saffron, one ounce; rectified spirit of wine, proof-spirit, of each one pound. Digest the myrrh with the spirit for the space of four days; then add the aloes in powder, and the saffron; continue the digestion for two days longer, suffer the feces to subside, and pour off the clear elixir.

These two formulae, though the mode of preparation be somewhat varied, do not materially differ from each other; and both may be considered as being the elixir proprietatis of Paracelsus, improved with regard to the manner of preparation. The myrrh, saffron, and aloes, have been usually directed to be digested in the spirit together: by this method, the menstruum soon loads itself with the latter, so as scarcely to take up any of the myrrh; while a tincture, extracted first from the myrrh, readily dissolves a large quantity of the others. The alkaline salt, commonly ordered in these preparations with a view to promote the dissolution of the myrrh, we have already observed to be useless; and accordingly it is now omitted. Instead of employing the rectified spirit alone, the Edinburgh college have used an equal portion of proof-spirit, which is not only a more complete menstruum, but also renders the medicine less heating.

This medicine is highly recommended, and not undeservedly, as a warm stimulant and aperient. It strengthens the stomach and other viscera, cleanses the first passages from tenacious phlegm, and promotes the natural secretions in general. Its continued use has frequently done much service in cachectic and icteric cases, uterine obstructions, and other similar disorders; particularly in cold pale phlegmatic habits. Where the patient is of a hot bilious constitution and florid complexion, this warm stimulating medicine is less proper, and sometimes prejudicial. The dose may be from twenty drops to a tea-spoonful or more, two or three times a day, according to the purposes which it is intended to answer.

Vitriolic elixir of aloes, or proprietatis. E.

Take of myrrh, socotrine aloes, each an ounce and a half; English saffron, one ounce; dulcified spirit of vitriol, one pound. Digest the myrrh with the spirit for four days in a close vessel; then add the saffron and aloes. Digest again four days; and when the feces have subsided pour off the elixir.

The Edinburgh college have reformed this preparation considerably; and especially by directing the myrrh to be digested first, for the same reasons as were observed on the preceding article. Here the dulcified spirit of vitriol is very judiciously substituted for the spirit of sulphur, ordered in other books of pharmacy to be added to the foregoing preparation; for that strong acid precipitates from the liquor great part of what it had before taken up from the other ingredients; whereas, when the acid is previously combined with the vinous spirit, and thereby dulcified, as it is called, it does not impede its dissolving power. This elixir possesses the general virtues of the preceding, and is, in virtue of the menstruum, preferred to it in hot constitutions and weaknesses of the stomach.

Aromatic tincture. E.

Take of cinnamon, six drams; lesser cardamom-seeds, one ounce; garden-angelica root, three drams; long pepper, two drams; proof-spirit, two pounds and an half. Macerate for seven days, and filter the tincture.

This preparation is improved from the preceding editions by the omission of some articles, either superfluous or foreign to the intention; galangal, gentian, zedoary, bay-berrys, and calamus aromaticus. As now reformed, it is a sufficiently elegant warm aromatic.

This very warm aromatic is too hot to be given without dilution. A tea-spoonful or two may be taken in wine or any other convenient vehicle, in languors, weak. weakness of the stomach, flatulencies, and other similar complaints; and in these cases it is often employed with advantage.

**Tincture of asafoetida. L.**

Take of asafoetida, four ounces; rectified spirit of wine, two pints. Digest with a gentle heat for six days, and strain.

**Fetid tincture. E.**

Take of asafoetida, two ounces; vinous spirit of sal ammoniac one pound. Macerate for six days in a close shut vessel, and strain.

Of these two formulae, the last is perhaps most generally useful: The vinous spirit of sal ammoniac is not only a more powerful menstruum than the rectified spirit of wine, but also coincides with the general virtues of the remedy.

This tincture possesses the virtues of the asafoetida itself; and may be given from ten drops to fifty or sixty. It was first proposed to be made with proof-spirit; this dissolves more of the asafoetida than a rectified one; but the tincture proves turbid; and therefore rectified spirit, which extracts a transparent one, is very justly preferred where ardent spirit is to be employed: and with this menstruum we can at least exhibit the asafoetida in a liquid form to a greater extent.

**Tincture of balsam of Peru. L.**

Take of balsam of Peru, four ounces; rectified spirit of wine, one pint. Digest until the balsam be dissolved.

The whole of the Peruvian balsam is dissolved by spirit of wine: this therefore may be considered as a good method of freeing it from its impurities; while at the same time it is thus reduced to a state under which it may be readily exhibited: but at present it is very little employed, unless in composition, either under this or any other form.

**Tincture of balsam of Tolu.**

Take of balsam of Tolu, one ounce and an half; rectified spirit of wine, one pint. Digest until the balsam be dissolved, and strain. L.

Take of balsam of Tolu, an ounce and an half; rectified spirit of wine, one pound. Digest until the balsam be dissolved, and then strain the tincture. E.

This solution of balsam of Tolu possesses all the virtues of the balsam itself. It may be taken internally, with the several intentions for which that valuable balsam is proper, to the quantity of a tea-spoonful or two, in any convenient vehicle. Mixed with the plain syrup of sugar, it forms an elegant balsamic syrup.

**Compound tincture of benzoin. L.**

Take of benzoin, three ounces; storax strained, two ounces; balsam of Tolu, one ounce; socotrine aloes, half an ounce; rectified spirit of wine, two pints. Digest with a gentle heat for three days, and strain.

**Traumatic balsam. E.**

Take of benzoin, three ounces; balsam of Peru, two ounces; hepatic aloes, half an ounce; rectified spirit of wine, two pounds. Digest them in a sand bath for the space of ten days, and then strain the balsam.

Although the London college have changed the name of this composition, yet they have made very little alteration on the formula which, in their last edition, had the name of Traumatic balsam; a name which it still retains in the Edinburgh pharmacopoeia; and both may be considered as elegant contractions of some very complicated compositions, which were celebrated under different names; such as Baume de Commandeur, Wade's balsam, Friar's balsam, Jesuit's drops, &c. These, in general, consisted of a confused farra-go of discordant substances. They, however, derived considerable activity from the benzoin and aloes; and every thing to be expected from them may readily be obtained from the present formulae.

The compound tincture of benzoin, or traumatic balsam, stands highly recommended, externally, for cleansing and healing wounds and ulcers, for dissolving cold tumors, allaying gouty, rheumatic, and other old pains and aches; and likewise internally, for warming and strengthening the stomach and intestines, expelling flatulencies, and relieving colic complaints. Outwardly, it is applied cold on the part with a feather; inwardly, a few drops are taken at a time, in wine or any other convenient vehicle.

There is, however, reason to think that its virtues have been considerably over-rated; and at present it is much less employed than formerly, recourse being chiefly had to it in cases of recent wounds, with the view of stopping hemorrhages, and of promoting healing by the first intention, as it is called.

**Tincture of the Spanish fly.**

Take of bruised cantharides, two drams; cochineal, powdered, half a dram; proof-spirit, one pint and an half. Digest for eight days, and strain. L.

Take of cantharides, one dram; proof-spirit, one pound. Digest for four days, and strain through paper. E.

These tinctures possess the whole virtues of the fly, and are the only preparations of it designed for internal use: tinctures being by far the most commodious and safe form for the exhibition of this active drug. The two tinctures are scarcely different in virtue from each other. The cochineal is used only as a colouring ingredient: the gum-guaiacum, camphor, and essential oil of juniper-berries, which were formerly added, however well adapted to the intentions of cure, could be of little consequence in a medicine limited to so small a dose. If any additional substances should be thought requisite for promoting the effect of the cantharides, whether as a diuretic, as a detergent in ulcerations of the urinary passages, or as a specific restringent of seminal gleets and the fluor albus, they are more advantageously joined extemporaneously to the tincture, or interposed by themselves at proper intervals. The usual dose of these tinctures is from ten to twenty drops; which may be taken in a glass of water, or any other more agreeable liquor, twice a day; and increased by two or three drops at a time, according to the effect.

The tincture of cantharides has of late been highly celebrated as a successful remedy in diabetic cases; and in some instances of this kind, its use has been pushed to a very considerable extent, without giving rise to any strangulous affections: But we have not found it productive of a change for the better in any of those cases of diabetes in which we have tried it.

**Tincture of cardamom.**

Take of lesser cardamom seeds, husked and bruised, three ounces; proof-spirit, two pints. Digest for eight days, and strain. L.

Take of lesser cardamom seeds, six ounces; proof-spirit, two pounds and a half. Macerate for eight days, and strain through paper. E.

The tincture of cardamom has been in use for a considerable time. It is a pleasant, warm cordial; and may be taken, along with any proper vehicle, from a dram to a spoonful or two.

**Compound tincture of cardamom.** L.

Take of lesser cardamom seeds, husked, caraway-seeds, cochineal, each, powdered, two drams; cinnamon, bruised, half an ounce; raisins, stoned, four ounces; proof-spirit, two pints. Digest for fourteen days, and strain.

This tincture contains so small a proportion of cardamom as to be hardly entitled to derive its name from that article; and from the large proportion of raisins which it contains, the influence of the aromatics must be almost entirely prevented, while, at the same time, from these it cannot be supposed to obtain any active impregnation.

**Tincture of cascarilla.** L.

Take of the bark of cascarilla, powdered, four ounces; proof-spirit, two pints. Digest with a gentle heat for eight days, and strain.

Proof-spirit readily extracts the active powers of the cascarilla; and the tincture may be employed to answer most of those purposes for which the bark itself is recommended: But in the cure of intermittents, it in general requires to be exhibited in substance.

**Tincture of castor.**

Take of Russia castor, powdered, two ounces; proof-spirit, two pints. Digest for ten days, and strain. L.

Take of Russia castor, an ounce and a half; rectified spirit of wine, one pound; digest them with a gentle heat for six days, and afterwards strain off the liquor. E.

An alkaline salt was formerly added in this last prescription, which is here judiciously rejected, as being at least an useless, if not a prejudicial, ingredient. It has been disputed, whether a weak or rectified spirit, and whether cold or warm digestion, are preferable for making this tincture. To determine this point, the following experiment has been mentioned. "Some fine Siberia castor having been infused in good French brandy, without heat, for twenty days, the tincture proved very weak: On the same individual castor (the magma or residuum of the former tincture) the same quantity of rectified spirit was poured as before of brandy; and after a few hours warm digestion, a tincture was extracted much stronger than the other." But this experiment is not satisfactory: the effects of the two menstrua, and of heat, having been respectively compared in very different circumstances.

From other trials, it appears that castor, macerated without heat, gives out its finer and most grateful parts to either spirit, but most perfectly to the rectified. That heat enables both menstrua to extract greatest part of its grosser, and more nauseous matter; and proof-spirit extracts this last more readily than rectified.

The tincture of castor is recommended in most kinds of nervous complaints and hysterical disorders: In the latter it sometimes does service, though many have complained of its proving ineffectual. The dose is from twenty drops to forty, fifty, or more.

**Compound tincture of castor.** E.

Take of Russia castor, one ounce; asafoetida, half an ounce; vinous spirit of sal ammoniac, one pound. Digest for six days in a close stopped phial, frequently shaking the vessel; and then strain the tincture.

This composition is a medicine of real efficacy, particularly in hysterical disorders, and the several symptoms which accompany them. The spirit here used is an excellent menstruum, both for the castor and the asafoetida, and greatly adds to their virtues.

**Tincture of catechu.** L.

Take of catechu, three ounces; cinnamon, bruised, two ounces; proof-spirit, two pints. Digest for three days, and strain.

**Japonic tincture.** E.

Take of Japan earth, three ounces; cinnamon, two ounces; proof-spirit, two pounds and a half. After digestion for eight days, let the tincture be passed through a strainer.

A tincture of this kind, with the addition of Peruvian bark, ambergris, and musk, to the ingredients above directed, was formerly kept in the shops. The tincture here received is preferable for general use: where any other ingredients are required, tinctures of them may be occasionally mixed with this in extemporaneous prescription. The cinnamon is a very useful addition to the catechu, not only as it warms the stomach, &c., but likewise as it improves the roughness and stringency of the other.

The tincture is of service in all kinds of defluxions, catarrhs, loofenesses, uterine fluors, and other disorders, where mild astringent medicines are indicated. Two or three tea-spoonfuls may be taken every now and then in red wine, or any other proper vehicle.

**Tincture of cinnamon.**

Take of cinnamon, bruised, one ounce and an half; proof-spirit, one pint. Digest for ten days, and strain. L.

Take of cinnamon, three ounces; proof-spirit, two pounds and a half. Macerate for eight days, and strain. E.

The tincture of cinnamon possesses the refringent virtues of the cinnamon, as well as its aromatic cordial ones; and in this respect it differs from the distilled waters of that spice.

**Compound** **Compound tincture of cinnamon. L.**

Take of cinnamon, bruised, fix drams; lesser cardamom-seeds, husked, three drams; long pepper, ginger, of each, in powder, two drams; proof-spirit, two pints. Digest for eight days and strain.

From the different articles which this tincture contains, it must necessarily be of a more hot and fiery nature than the former, though much less strongly impregnated with the cinnamon.

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**Tincture of colomba. L.**

Take of colomba-root, powdered, two ounces and an half; proof-spirit, two pints. Digest for eight days, and strain.

The colomba readily yields its active qualities to the menstruum here employed; and accordingly, under this form, it may be advantageously employed against bilious vomitings, and those different stomach ailments, in which the colomba has been found useful; but where there does not occur some objection to its use in substance, that form is in general preferable to the tincture, which is now for the first time introduced into the London pharmacopoeia.

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**Tincture of orange peel. L.**

Take of the fresh exterior peel of Seville oranges, three ounces; proof-spirit, two pints. Digest for three days, and strain.

By this menstruum, both the bitter quality of the orange skins, and likewise their peculiar essential oil, are extracted; hence it may be employed for any purpose in medicine which these are capable of answering. It is, however, but rarely used; and, as well as the former, has now only for the first time a place in the London pharmacopoeia.

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**Tincture of Peruvian bark.**

Take of Peruvian bark, powdered, four ounces; proof-spirit, two pints. Digest with a gentle heat for eight days, and strain. L.

Take of Peruvian bark, four ounces; proof-spirit, two pounds and a half. Digest for ten days, and strain. E.

A medicine of this kind has been for a long time pretty much in esteem, and usually kept in the shops, though but lately received into the pharmacopoeias. Some have employed highly-rectified spirit of wine as a menstruum; which they have taken care fully to saturate, by digestion on a large quantity of the bark. Others have thought of assuaging the action of the spirit by the addition of a little fixed alkaline salt, which does not however appear to be of any advantage; and others have given the preference to the vitriolic acid, which was supposed, by giving a greater confidence to the spirit, to enable it to sustain more than it would be capable of doing by itself; at the same time that the acid improves the medicine by increasing the roughness of the bark. This last tincture, and that made with rectified spirit, have their advantages; though, for general use, that above directed is the most convenient of any, the proof spirit extracting nearly all the virtues of the bark. It may be given from a tea spoonful to half an ounce, or an ounce, according to the different purposes it is intended to answer.

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**Compound tincture of Peruvian bark. L.**

Take of Peruvian bark, powdered, two ounces; exterior peel of Seville oranges, dried, one ounce and an half; Virginian snake-root, bruised, three drams; saffron, one dram; cochineal, powdered, two scruples; proof-spirit, twenty ounces. Digest for fourteen days, and strain.

This has been for a considerable time celebrated under the title of Huskham's tincture of bark.

The substances here joined to the bark, in some cases, promote its efficacy in the cure of intermittents, and not unfrequently are absolutely necessary. In some ill habits, particularly where the viscera and abdominal glands are obstructed, the bark, by itself, proves unsuccessful, if not injurious; while given in conjunction with stimulating stomachics and deobstruents, it more rarely fails of the due effect. Orange-peel and Virginian snake-root are among the best additions for this purpose; to which it is thought by some necessary to join chalybeate medicines also.

As a corroborant and stomachic, it is given in doses of two or three drams; but when employed for the cure of intermittents, it must be taken to a greater extent. For this purpose, however, it is rarely employed, unless with those who are averse to the use of the bark in substance, or whose stomachs will not retain it under that form.

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**Tincture of saffron. E.**

Take of English saffron, one ounce; proof-spirit, fifteen ounces. After digesting them for five days, let the tincture be strained through paper.

This tincture is similar in virtue to the saffron wine. A spirituous menstruum is here preferred to the wine, as a tincture drawn with the former retains its elegant colour longer, and is not apt to deposit in keeping any part of what it had taken up from the saffron. The shops have been accustomed to employ treacle water as a menstruum for saffron, with a view to the promoting its efficacy with the intention of operating as an alexipharmac; but the acid in that compound water soon destroys the colour of the tincture.

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**Tincture of muriated iron. L.**

Take of the rust of iron, half a pound; muriatic acid, three pounds; rectified spirit of wine, three pints. Pour the muriatic acid on the rust of iron in a glass vessel; and shake the mixture now and then during three days. Set it by that the feces may subside; then pour off the liquor; evaporate this to one pint, and, when cold, add to it the vinous spirit.

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**Tincture of iron. E.**

Take of the scales of iron, purified and powdered, three ounces; muriatic acid, as much as is sufficient to dissolve the powder. Digest with a gentle heat; and the powder being dissolved, add of rectified spirit of wine as much as will make up of the whole liquor two pounds and a half.

Of these two formulae, that of the Edinburgh college is, in our opinion, in fever respects entitled to the preference. The scales are much fitter for giving a proper solution than the rust. The strength of the muriatic acid is so variable, that the quantity is left to the judgment of the operator. If the acid be superabundant, the solution is of a green colour; if it be fully saturated with the iron, it is more or less of a reddish or yellow colour; and this serves as a pretty accurate criterion. As the muriatic acid combines less intimately with rectified spirit than any of the fossil acids, so the after-process of dulcification scarcely, if at all, impairs the solvent power of the acid; though, when the dulcification happens to be more than usually complete, a small quantity of ferruginous matter is sometimes precipitated on adding the rectified spirit to the solution. But as the rectified spirit increases the volatility of the acid, so if it was added at first, we should lose much more of the menstruum by the heat employed during the digestion. When this tincture is well prepared, it is of a yellowish-red colour; if the acid be superabundant, it is more or less of a greenish hue; and if the rectified spirit has been impregnated with the astringent matter of oak casks, it assumes an inky colour.

All the tinctures of iron are no other than real solutions of the metal made in acids, and combined with vinous spirits. The tinctures here directed differ from each other only in strength, the acid being the same in both. In our former pharmacopeias, there was a tincture from the matter which remains after the sublimation of the martial flowers; which, though it appears to be a good one, is now expunged as superfluous. Some have recommended dulcified spirit of nitre as a menstruum; but though this readily dissolves the metal, it does not keep it suspended. The marine is the only acid that can be employed for this purpose.

These tinctures are greatly preferable to the calces or croci of iron, as being not only more speedy, but likewise more certain in their operation. The latter, in some cases, pass off through the intestinal tube with little effect; while the tinctures scarce ever fail. From ten to twenty drops of either of the tinctures may be taken two or three times a-day, in any proper vehicle; though it is seldom advisable to extend the dose of any tinctures of iron so far as the last of these quantities, especially with the tincture in spirit of salt, which is exceedingly strong of the iron.

**Tincture of foot. E.**

Take of shining wood-fool, one ounce; asafoetida, half an ounce; rectified spirit of wine, proof-spirit, of each half a pound. Digest for six days, and strain.

The proof-spirit is not liable to any objection here, as giving a turbid tincture; for when foot is added, whatever spirit be employed, the tincture will not prove transparent. Fuller, in his Pharmacopoeia Domestica, has a medicine under the title of hysterical tincture, similar to this, only with a little myrrh, which is no very material addition to asafoetida and foot. These medicines are found serviceable, not only in hysterical cases, but likewise in other nervous disorders. They may be given from a tea-spoonful to a table-spoonful twice a-day.

This medicine has by some been thought serviceable in obstructions of the menstres; but its activity may be considered as depending much more on the asafoetida than on the foot.

**Tincture of galbanum. L.**

Take of galbanum, cut into small pieces, two ounces; proof-spirit, two pints. Digest with a gentle heat for eight days, and strain.

This tincture is now for the first time introduced by the London college, and may be usefully employed for answering several purposes in medicine. Galbanum is one of the strongest of the fetid gums; and although less active, yet much less disagreeable than asafoetida; and under the form of tincture it may be successfully employed in cases of flatulence and hysteria, where its effects are immediately required, particularly with those who cannot bear asafoetida.

**Compound tincture of gentian. L.**

Take of gentian root, sliced and bruised, two ounces; exterior dried peel of Seville oranges, one ounce; lesser cardamom seeds, hulled and bruised, half an ounce; proof-spirit, two pints. Digest for eight days, and strain.

**Bitter tincture, or stomachic elixir. E.**

Take of gentian-root, two ounces; Seville orange-peel, dried, one ounce; white canella, half an ounce; cochineal, half a dram; proof-spirit, two pounds and a half. Macerate for four days, and strain through paper.

These are very elegant spirituous bitters. As the preparations are designed for keeping, lemon-peel, an excellent ingredient in the watery bitter infusions, has, on account of the perishableness of its flavour, no place in these. The aromatics are here a very commodious ingredient, as in this spirituous menstruum they are free from the inconvenience with which they are attended in other liquors, of rendering them untransparent.

**Elixir of guaiacum. E.**

Take of gum-guaiacum, one pound; balsam of Peru, three drams; rectified spirit of wine, two pounds and a half. Digest for ten days, and strain.

This tincture may be considered as nearly agreeing in medical virtues with the two following. It is, however, less in use; but it may be employed with advantage in those cases where an objection occurs to the menstruum used in forming the others.

**Tincture of gum-guaiacum. L.**

Take of gum-guaiacum, four ounces; compound spirit of ammonia, a pint and a half. Digest for three days, and strain.

**Volatile elixir of guaiacum. E.**

Take of gum-guaiacum, four ounces; balsam of Peru, two drams; distilled oil of sassafras, half a dram; vinous spirit of sal ammoniac, a pound and an half. Macerate for six days in a close vessel, and strain.

In the last of these formulae, the vinous spirit of sal ammoniac is less acrimonious than the menstruum directed by the London college; and the balsam of Peru, and distilled oil of sassafras, are useful additions, by increasing the permanence of its operation as a general stimulant, or more particularly as a diaphoretic.

These are very elegant and efficacious tinctures; the volatile spirit excellently dissolving the gum, and at the same time promoting its medicinal virtue. In rheumatic cases, a tea or even table spoonful, taken every morning and evening in any convenient vehicle, particularly in milk, has proved of singular service.

**Tincture of black hellebore. L.**

Take of black hellebore root, in coarse powder, four ounces; cochineal, powdered, two scruples; proof-spirit, two pints. Digest with a gentle heat for eight days, and strain.

**Tincture of melampodium, or black hellebore. E.**

Take of black hellebore root, four ounces; cochineal, half a dram; proof-spirit two pounds and a half. Digest them together for eight days, and afterwards filter the tincture through paper.

This is perhaps the best preparation of hellebore, when designed for an alternative, the menstruum here employed extracting the whole of its virtues. It has been found, from experience, particularly serviceable in uterine obstructions; in sanguine constitutions, where chalybeates are hurtful, it has been said that it seldom fails of exciting the menstrual evacuations, and removing the ill consequences of their suppression. So great, according to some, is the power of this medicine, that wherever, from an ill conformation of the parts, or other causes, the expected discharge does not succeed on the use of it, the blood, as Dr Mead has observed, is so forcibly propelled, as to make its way through other passages. A ten spoonful of the tincture may be taken twice in a day in warm water or any other convenient vehicle.

The college of Edinburgh had formerly a tincture of this root with wine. Proof spirit is undoubtedly preferable, both as a menstruum, and as being better fitted for keeping.

**Tincture of jalap.**

Take of powdered jalap root, eight ounces; proof-spirit, two pints. Digest with a gentle heat for eight days, and strain. L.

Take of jalap, in coarse powder, three ounces; proof-spirit, fifteen ounces. Digest them for eight days, and strain the tincture. E.

Rectified spirit of wine was formerly ordered for the preparation of this tincture; but rectified spirit dissolving little more than the pure resinous parts of the jalap, rendered the use of the medicine somewhat less commodious than that of the tincture prepared with proof-spirit. Most of the tinctures made in rectified spirit, diluted with water, so as to be fit for taking, form a turbid white mixture. Many of them are safely taken in this form, without any further addition: but the cathartic ones are never to be ventured on without an admixture of syrup or mucilage to keep the resin united with the liquor; for if it separates in its pure undivided state, it never fails to produce violent gripes.

**Vol. XIV. Part II.**

Some have preferred to the tinctures of jalap, a solution in spirit of wine of a known quantity of the resin extracted from the root; and observe, that this solution is more certain in strength than any tincture that can be drawn from the root directly. For, as the purgative virtue of jalap resides in its resin, and as all jalap appears from experiment not to be equally resinous, some sorts yielding five, and others not three, ounces of resin from sixteen; it follows, that although the root be always taken in the same proportion to the menstruum, and the menstruum always exactly of the same strength, it may, nevertheless, according to the degree of goodness of the jalap, be impregnated with different quantities of resin, and consequently prove different in degree of efficacy. Though this objection against the tincture does not reach so far as some seem to suppose, it certainly behoves the apothecary to be careful in the choice of the root. The inferior sorts may be employed for making resin of jalap, which they yield in as great perfection, though not in so large quantity, as the best. Neumann thinks even the worm-eaten jalap as good for that purpose as any other.

**Tincture of gum-kino. E.**

Take of gum-kino, two ounces; proof-spirit, a pound and an half. Digest eight days, and strain.

The substance called gum-kino seems to be really a gum-resin; on which account proof-spirit is the most proper menstruum. This preparation must therefore possess the virtues of the substance; and it is perhaps one of the best forms under which it can be exhibited in obstinate diarrhoeas, and in cases of lienteria; but in hemorrhages, it is in general proper to exhibit it either in infusion or distilled; yet we cannot help thinking that the want of this tincture is an omission in the London pharmacopoeia.

**Compound tincture of lavender. L.**

Take of spirit of lavender, three pints; rosemary, one pint; cinnamon bruised, nutmegs bruised, of each half an ounce; red saunders, one ounce. Digest for ten days, and strain.

**Compound spirit of lavender. E.**

Take of simple spirit of lavender, three pounds; simple spirit of rosemary, one pound; cinnamon, one ounce; cloves, two drams; nutmeg, half an ounce; red saunders, three drams. Macerate seven days, and strain.

These two compositions, although varying a little from each other, both with respect to their ingredients and names, may yet be considered as precisely the same. Although the London college, in the present edition of their pharmacopoeia, have made many useful alterations with respect to names, yet the propriety of the change here adopted may perhaps be doubted: For it cannot with justice be styled a tincture of lavender, when the distilled spirit of that plant is employed only as a menstruum. If, therefore, it seemed necessary to refer it to the head of tinctures, it ought to have been denominated from the cinnamon or nutmegs; but since the activity of this article very much depends on the spirit of lavender, vender, the old name is in our opinion justly preferable to the new one.

The red saunders is of no farther use in these compositions than as a colouring ingredient. If a yellow spirit was liked, the yellow saunders would be an excellent article, as it not only communicates a fine colour, but likewise a considerable share of medicinal virtue. A spirit distilled from the flowers of lavender and sage, in due proportion, and digested in the cold for a little time with some cinnamon, nutmegs, and yellow saunders, proves a very elegant and grateful one. Where essential oils are employed, particular care must be had in the choice of them; for their goodnes that of the medicine depends. The digestion of the spirit with the spices, &c. should be performed without heat, otherwise the flavour of the medicine will be injured. These spirits are grateful reviving cordials: though considerably more simple, they are not less elegant or valuable than many other more elaborate preparations. This medicine has long been held in great esteem, under the name of Palfy drops, in all kinds of languors, weaknesses of the nerves, and decays of age. It may be conveniently taken on sugar, from ten to eighty or a hundred drops.

**Tincture of myrrh. E.**

Take of musk, two drams; rectified spirit of wine, one pound. Digest for ten days, and strain.

Rectified spirit is the most complete menstruum for musk; but in this form it is often impossible to give such a quantity of the musk as is necessary for our purpose; and hence this article is more frequently employed under the form of julep or bolus.

**Tincture of myrrh.**

Take of myrrh, bruised, three ounces; proof-spirit, a pint and an half; rectified spirit of wine, half a pint. Digest with a gentle heat for eight days, and strain. L.

Take of myrrh, three ounces; proof-spirit, two pounds and a half. After digestion for ten days, strain off the tincture. E.

The pharmaceutical writers in general have been of opinion, that no good tincture can be drawn from myrrh by spirit of wine alone, without the assistance of fixed alkaline salts. But it appears from proper experiments, that these salts only heighten the colour of the tincture, without enabling the menstruum to dissolve any more than it would by itself. Rectified spirit extracts, without any addition, all that part of the myrrh in which its peculiar smell and taste reside, viz. the resin: and proof-spirit dissolves almost the whole of the drug, except its impurities: hence the combination of these two directed by the London college is perhaps preferable to either by itself.

Tincture of myrrh is recommended internally for warming the habit, attenuating viscid juices, strengthening the solids, opening obstructions, particularly those of the uterine vessels, and resisting putrefaction. Boerhaave greatly esteems it in all languid cases proceeding from simple inactivity; in those female disorders which are occasioned by an aqueous, mucous, flaccid indisposition of the humours, and a relaxation of the vessels; in the fluor albus, and all diseases arising from a like cause. The dose is from fifteen drops to forty or more. The medicine may doubtless be and given in these cases to advantage; though with us, it is more commonly used externally for cleansing foul ulcers and promoting the exfoliation of carious bones.

**Tincture of opium. L.**

Take of hard purified opium, powdered, ten drams; proof-spirit, one pint. Digest for ten days, and strain.

**Tincture of opium, commonly called liquid laudanum. E.**

Take of opium, two ounces; spirituous cinnamon-water, one pound and a half. Digest four days, and strain off the tincture.

These are very elegant liquid opiates, the menstruum in the last dissolves nearly the whole substance of the opium, and effectually covers its ill flavour. It were to be wished that the shops were furnished with a liquid opiate, in which the proportion of menstruum was still much larger, so as to admit of the dose being determined by weight or measure; the method by drops seeming too precarious for a medicine of so powerful a kind. The following preparation is contrived with this view.

Take of thebaic extract, half a dram; highly rectified spirit of wine, called alcohol, ten ounces; simple cinnamon-water, twenty ounces. Digest them together until the opium be dissolved, and then filter the solution through paper.

This preparation is apprehended to be free from all the inconveniences attending the common opiate tinctures. The menstruum dissolves the whole of the opium except the impurities, and consequently the tincture is not liable to any uncertainty in point of strength. The dose may be ascertained to the greatest exactness; one grain of opium is contained in one ounce by measure, which is equal nearly to seven drams by weight. Neither the tinctures in wine nor proof-spirit are so well adapted for keeping as could be wished: in long standing, a part of the opium is gradually thrown off from both, and consequently the tinctures become gradually weaker: the part which thus separates, amounts sometimes, it is said, to near one-fourth of the quantity of opium at first dissolved: it floats on the surface of the vinous tincture, and in the spirituous sinks to the bottom. In the preparation here recommended, it has not been observed that any separation happens.

Instead of the cinnamon-water, pure water may be employed in the mixture: and where aromatic additions are wanted, either with a medicinal intention or for covering the ill smell of the opium, any proper tincture or distilled water may be contemporaneously joined. Saffron, an addition once employed by the Edinburgh college, has been considered as a corrector of opium; but the qualities it was supposed to correct are merely imaginary; nor indeed can that article be of much importance with any intention in the small quantity that enters a dose of the tincture; a grain of opium being accompanied with only half a grain of saffron.

A preparation in some respects similar to that here recommended was introduced into the Edinburgh phar- pharmacopoeia published in 1774, under the title of *tinctura meconii*. Each ounce of this tincture contained four grains of opium; and it was proposed that the doses of it should be measured, not by drops, but by weight: but as modern physicians are much more bold in giving opium than their predecessors, such a scrupulous accuracy in the dose is not thought at all necessary; and it is not probable that any dangerous consequence will ever arise, merely from a difference in the size of drops. This, however, might be the case, where the thebaic tincture is by accident taken for the tincture of meconium. To such mistakes, however, it was feared that the analogy of the articles, as well as the caution necessary with respect to both, might lead; and it was on many accounts safer to have but one liquid laudanum only. It is, however, much to be regretted, that the liquid laudanum of the London and Edinburgh colleges, which by the former is now styled *tinctura opii*, by the latter *tinctura thebaica*, should differ so much from each other in point of strength.

**Camphorated tincture of opium. L.**

Take of hard purified opium, flowers of benzoin, each one dram; camphor, two scruples; essential oil of aniseed, one dram; proof-spirit, two pints. Digest for three days.

**Paregoric elixir. E.**

Take of flowers of benzoin, English saffron, each three drams; opium, two drams; essential oil of aniseeds, half a dram; vinous spirit of sal ammoniac, fifteen ounces. Digest for four days in a clothe vessel, and strain.

These two, though differing not merely in name, may yet be considered as agreeing very nearly in their nature.

The most material differences in the last formula from the first are the substitution of the vinous spirit of sal ammoniac for the proof-spirit, and a larger proportion of opium; the vinous spirit of sal ammoniac is not only, perhaps, a more powerful menstruum, but in most instances coincides with the virtues of the preparation; but as the opium is the ingredient on which we place the principal dependence, so its proportion is increased, in order that we may give it in such a dose as that the acrimony of the menstruum shall not prove hurtful to the stomach.

The London formula is taken from Le Mort, with the omission of three unnecessary ingredients, honey, liquorice, and alkaline salt. It was originally called *elixir phthisicum*, which name it does not ill deserve. It contributes to allay the tickling which provokes frequent coughing; and at the same time is supposed to open the breast, and give greater liberty of breathing; the opium procures (as it does by itself) a temporary relief from the symptoms; while the other ingredients tend to remove the cause, and prevent their return. It is given to children against the chincough, &c. from five drops to twenty; to adults, from twenty to an hundred. In the London formula, half an ounce by measure contains about a grain of opium; but in the Edinburgh formula the proportion of opium is larger.

**Tincture of rhubarb.**

Take of rhubarb, sliced, two ounces; lesser cardamom seeds, hulled and bruised, half an ounce; saffron, two drams; proof-spirit, two pints. Digest for eight days, and strain. L.

Take of rhubarb, three ounces; lesser cardamom seeds, half an ounce; proof-spirit two pounds and a half. Digest for seven days, and strain. E.

**Compound tincture of rhubarb. L.**

Take of rhubarb sliced, two ounces; ginger powdered, saffron, each two drams; liquorice root, bruised, half an ounce; distilled water, one pint; proof-spirit, twelve ounces. Digest for fourteen days, and strain.

**Bitter tincture of rhubarb. E.**

Take of rhubarb two ounces; gentian-root, half an ounce; Virginian snake-root, one dram; proof-spirit, two pounds and a half. Digest for seven days, and then strain the tincture.

**Sweet tincture of rhubarb. E.**

It is made by adding to two pounds and a half of the strained tincture of rhubarb, four ounces of sugar-candy.

The last of these preparations is improved from the former editions. Two ounces of liquorice and one of raisins are supplied, by an increase of the sugar-candy.

All the foregoing tinctures of rhubarb are designed as stomachics and corroborants, as well as purgatives; spirituous liquors excellently extract those parts of the rhubarb in which the two first qualities reside, and the additional ingredients considerably promote their efficacy. In weakness of the stomach, indigestion, laxity of the intestines, diarrhoeas, colic, and other similar complaints, these medicines are frequently of great service; the second is also, in many cases, an useful addition to the Peruvian bark, in the cure of intermittents, particularly in cachectic habits, where the viscera are obstructed; with these intentions, a spoonful or two may be taken for a dose, and occasionally repeated.

**Elixir of aloes and rhubarb, commonly called sacred elixir. E.**

Take of rhubarb, cut small, ten drams; socotrine aloes, in powder, six drams; lesser cardamom seeds, half an ounce; proof-spirit, two pounds and a half. Digest for seven days, and then strain the elixir.

This preparation is very much employed as a warming cordial purge, and for the general purposes of aloetics; with which, however, it combines the medical properties of rhubarb.

**Compound tincture of savin. L.**

Take of extract of savin, one ounce; tincture of castor, one pint; myrrh, half a pint. Digest till the extract of savin be dissolved, and then strain.

This preparation had a place in the last edition of our pharmacopoeia, under the title of *Elixir myrrhae compositum*. This preparation is improved from one described in some former dispensaries under the name of uterine elixir. It is a medicine of great importance in uterine obstructions, and in hypochondriacal cases; though, possibly, means might be contrived of superadding more effectually the virtues of senna to a tincture of myrrh and caltrop. It may be given from five drops to twenty or thirty, or more, in pennyroyal water, or any other suitable vehicle.

Tincture of squill. L.

Take of squills, fresh dried, four ounces; proof-spirit, two pints. Digest for eight days, and pour off the liquor.

For extracting the virtues of squills, the menstruum which has hitherto been almost solely employed is vinegar. There are, however, cases in which ardent spirit may be more proper; and by the menstruum here directed its virtues are fully extracted. Hence it is with propriety that the London college have introduced this form, as well as the vinegar and oxymel. But, in general, the purpose to be answered by squills may be better obtained by employing it in substance than in any other form.

Antiphthisical tincture. E.

Take of sugar of lead, an ounce and a half; vitriol of iron, one ounce; rectified spirit of wine, one pound.

Let a tincture be extracted without heat.

The reducing of the salts separately into powder, and performing the digestion without heat, are very necessary circumstances: for if the ingredients be attempted to be pulverized together, they will grow soft and almost liquid; and if heat be used, scarce any tincture will be obtained.

This tincture is sometimes given in doses of twenty or thirty drops for restraining moderate secretions, particularly the colligative sweats attending hectic fevers and phthisical disorders; whence the name antiphthisical tincture. It is undoubtedly a medicine of great efficacy in these cases, but too dangerous to be rashly ventured on. Some have supposed that it does not contain any of the sugar of lead; but experiments made for that purpose have shown the contrary.

We must, however, consider the above preparation as unscientific. Both the acetous and vitriolic acid have a greater attraction for iron than for lead: and though the vitriolic be capable of discharging the acetous acid, yet it makes not only in its entire state a less perfect union with lead than the acetous acid, but it is now also combined with iron, for which it has a greater attraction, and can therefore only act on the salt of lead in proportion as it is superabundant in the salt of copperas; but in proportion as the vitriolic disengages the acetous acid from the lead, the last, in its turn, will attach itself to the iron. On the whole, it is difficult to ascertain the precise nature of this preparation; it seems always, however, to contain a quantity of lead in a saline state, sufficient to expunge it from prudent practice: or, at least, if in these cases in which it has hitherto been employed, lead be thought necessary, the salt of lead may with more safety and advantage be given in its solid state, particularly when combined with opium: and it is probably on this account that the present formula has now no place in the London pharmacopoeia.

Tincture of senna. L.

Take of senna, one pound; caraway seeds, bruised, one ounce and an half; lesser cardamom seeds, husked and bruised, half an ounce; raisins, stoned, fifteen ounces; proof-spirit, one gallon. Digest for fourteen days, and strain.

Compound tincture of senna, commonly called Elixir of health. E.

Take of senna leaves, two ounces; jalap root, one ounce; coriander seeds, half an ounce; proof-spirit, two pounds and a half. Digest for seven days, and to the strained liquor add four ounces of sugar-candy.

Both these tinctures are useful carminatives and cathartics, especially to those who have accustomed themselves to the use of spirituous liquors; they oftentimes relieve flatulent complaints and colics, where the common cordials have little effect: the dose is from one to two ounces. Several preparations of this kind have been offered to the public under the name of Duffy's elixir: the two above are equal to any, and superior to most of them. The last in particular is a very useful addition to the caltrop oil, in order to take off its mawkish taste: and as coinciding with the virtues of the oil, it is therefore much preferable to brandy, shrub, and such like liquors, which otherwise are often found necessary to make the oil sit on the stomach.

Tincture of snake root.

Take of Virginian snake-root, three ounces; proof-spirit, two pints. Digest for eight days, and strain. L.

Take of Virginian snake-root, two ounces; cochineal, one dram; proof-spirit, two pounds and a half. Digest in a gentle heat for four days, and then strain the tincture. E.

The tincture of snake-root was in a former pharmacopoeia directed to be prepared with the tincture of salt of tartar, which being now expunged, it was proposed to the college to employ rectified spirit; but as the heat of this spirit prevents the medicine from being taken in so large a dose as it might otherwise be, a weaker spirit was chosen. The tincture made in this menstruum, which extracts the whole virtues of the root, may be taken to the quantity of a spoonful or more every five or six hours; and to this extent it often operates as an useful diaphoretic.

Tincture of valerian. L.

Take of the root of wild valerian, in coarse powder, four ounces; proof-spirit, two pints. Digest with a gentle heat for eight days, and strain.

The valerian root ought to be reduced to a pretty fine powder, otherwise the spirit will not sufficiently extract its virtues. The tincture proves of a deep colour, and considerably strong of the valerian; though it has not been found to answer so well in the cure of epileptic disorders as the root in sublance, exhibited in the form of powder, or bolus. The dose of the tincture is, from half a spoonful to a spoonful or more, two or three times a-day. Part II.

**PHARMACY.**

**Volatile tincture of valerian.**

Take of the root of wild valerian, four ounces; compound spirit of ammonia, two pints. Digest for eight days, and strain. L.

Take of wild valerian root, two ounces; vinous spirit of sal ammoniac, one pound. Macerate for six days in a clothe vessel, and strain. E.

Both the compound and vinous spirit of sal ammoniac are here excellent menstrua, and at the same time considerably promote the virtues of the valerian, which in some cases wants an assistance of this kind. The dose may be a tea spoonful or two.

**Tincture of veratrum, or white hellebore.** E.

Take of white hellebore root, eight ounces; proof-spirit, two pounds and a half. Digest them together for ten days, and filter the tincture through paper.

This tincture is sometimes used for acuating cathartics, &c. and as an emetic in apoplectic and maniacal disorders. It may likewise be so managed as to prove a powerful alternative and deobstruent in cases where milder remedies have little effect. But a great deal of caution is requisite in its use: the dose, at first, ought to be only a few drops; if considerable, it proves violently emetic or cathartic.

**Acid elixir of vitriol.** E.

Take of rectified spirit of wine, two pounds; drop into it by little and little six ounces of vitriolic acid; digest the mixture with a very gentle heat in a clothe vessel for three days, and then add of cinnamon, an ounce and a half; ginger, one ounce. Digest again in a clothe vessel for six days, and then filter the tincture through paper placed in a glass funnel.

The intention in this process is, to obtain a tincture of aromatic vegetables, in spirit of wine, combined with a considerable proportion of vitriolic acid. When the tincture is first drawn with vinous spirit, and the acid added afterwards, the acid precipitates great part of what the spirit had before taken up: and on the other hand, when the acid is mixed with the spirit immediately before the extraction, it prevents the diffusion of all that it would have precipitated by the former way of treatment: by previously uniting the acid and the vinous spirit together by digestion, the inconvenience is somewhat lessened.

This is a valuable medicine in weakness and relaxations of the stomach and decay of constitution, particularly in those which proceed from irregularities, which are accompanied with slow febrile symptoms, or which follow the suppression of intermittents. It frequently succeeds after bitters and aromatics by themselves had availed nothing; and indeed great part of its virtues depend on the vitriolic acid; which, barely diluted with water, has, in those cases where the stomach could bear the acidity, produced happy effects.

Fuller relates (in his *Medicina Gymnastica*) that he was recovered by Mynsicht's elixir, from an extreme decay of constitution, and continual retchings to vomit. It may be given from 10 to 30 or 40 drops or more, according to the quantity of acid, twice or thrice a-day, at such times as the stomach is most empty. It is very usefully conjoined with the bark, both as covering its disagreeable taste and coinciding with its virtues.

**Sweet elixir of vitriol.** E.

This is made of the same aromatics, and in the same manner as the aromatic tincture; except that, in place of the vinous, the dulcified spirit of vitriol is employed.

This is designed for persons whose stomachs are too weak to bear the foregoing acid elixir; to the taste, it is gratefully aromatic, without any perceptible acidity. The dulcified spirit of vitriol, here directed, occasions little or no precipitation on adding it to the tincture.

A medicine of this kind was formerly in great esteem under the title of Pigani's volatile elixir of vitriol; the composition of which was first communicated to the public in the *Pharmacopoeia reformata*. It is prepared by digesting some volatile spirits of vitriol upon a small quantity of mint leaves curiously dried, till the liquor has acquired a fine green colour. If the spirit, as it frequently does, partakes too much of the acid, this colour will not succeed: in such case, it should be rectified from a little fixed alkaline salt.

**Camphorated spirit of wine.** E.

Take of camphor, one ounce; rectified spirit of wine, one pound. Mix them together, that the camphor may be dissolved. It may also be made with a double, triple, &c. proportion of camphor.

This solution of camphor is employed chiefly for external uses, against rheumatic pains, paralytic numbnesses, inflammations, for dissolving tumours, preventing gangrenes, or restraining their progress. It is too pungent to be exhibited internally, even when diluted, nor does the dilution succeed well; for on the admixture of aqueous liquors, the camphor gradually separates and runs together into little masses.

Hoffman, Rothen, and others, mention a camphorated spirit not subject to this inconvenience. It is prepared by grinding the camphor with somewhat more than an equal weight of fixed alkaline salt, then adding a proper quantity of proof-spirit, and drawing off one half of it by distillation. This spirit was proposed to be received into our pharmacopoeias, under the title of *Spiritus camphora tartarizatus*. But on trial, it did not answer expectation: some of the camphor rises with the spirit in distillation, though but a small quantity; whence, mixed with a large portion of water, it does not sensibly render it turbid; but in a proper quantity, it exhibits the same appearance as the more common camphorated spirit: it did not appear, that spirit distilled from camphor, with or without the alkaline salt, differed at all in this respect.

The most convenient method of uniting camphor with aqueous liquors, for internal use, seems to be by the mediation of almonds, or of mucilages; triturated with these, it readily mingles with water into the form of an emulsion, at the same time that its pungency is considerably abated. It may also be commodiously exhibited in the form of an oily draught, expressed oils totally dissolving it.

**The anodyne liniment, commonly called Anodyne balm.** E.

Take of opium, one ounce; white Caflile soap, four ounces; ounces; camphor, two ounces; essential oil of rosemary, half an ounce; rectified spirit of wine, two pounds. Digest the opium and soap in the spirit for three days; then to the strained liquor add the camphor and oil, diligently shaking the vessel.

The several ingredients in this formula are exceedingly well suited for the purposes expressed in the title of this preparation; the anodyne balsam has accordingly been used with much success to allay pains in strained limbs, and such like topical affections.

Saponaceous balsam or liniment. E.

This is made in the same manner and of the same ingredients as the anodyne balsam, only omitting the opium.

It is intended as a simplification and improvement of what had formerly the name of Opodeldock, and is employed with the same intentions as the two preceding.

Tincture of antimony. Roff.

Take of antimony, in powder, half a pound; salt of tartar, one pound; rectified spirit, three pints. Mix the antimony with the salt of tartar, and inject them by little and little into a crucible placed in a strong fire. Let the mixture melt thin, and continue in this state for half an hour; after which it is to be poured out into a hot and dry iron mortar. Powder the mass while hot, put it into a heated matras, and pour the spirit on it. Digest them together for three days, and then strain the tincture.

In this process, the alkaline salt unites with the sulphur of the antimony into a hepar; which communicates to the spirit a tincture similar to the tincture of sulphur. This antimonial tincture is supposed to contain likewise some of the reguline parts of the mineral, and is said to have sometimes provoked a puke when taken on an empty stomach, even in a small dose. It stands recommended in doses from ten to sixty drops or more, as a deobstruent, promoter of urine, and purifier of the blood. But there is probably no purpose to be answered by it, which may not be more effectually obtained by other antimonial preparations, particularly the wine of tartar of antimony.

Tincture of colocynth. Suec.

Take of colocynth, cut small, and freed from the seeds, one ounce; aniseed, one dram; proof-spirit, fourteen ounces. Macerate for three days, and strain through paper.

In this tincture we have the active purgative power of the colocynth. And although it be seldom used as a cathartic by itself, yet even in small quantity it may be advantageously employed to promote the operation of others.

Volatile tincture of copper. Gen.

Take of filings of copper, one dram; spirit of sal ammoniac, an ounce and a half. Mix them, and keep them in a vessel closely stoppered, which is to be frequently agitated, till the liquor becomes of a beautiful violet colour.

In this formula the copper is brought to a saline preparation by means of the volatile alkali. It may therefore be considered as very analogous to the ammoniacal copper. And where recourse is had to it in practice, it is employed with the same intentions.

Tincture of quassia. Suec.

Take of quassia, bruised, two ounces; proof-spirit, two pounds and an half. Digest for three days, and then strain through paper.

By proof-spirit the medical properties, as well as the sensible qualities of the quassia, are readily extracted. And under this form it may be advantageously employed for answering different purposes in medicine.

Tincture of lac. Suec.

Take of gum lac, powdered, one ounce; myrrh, three drams; spirit of scurvy-grafts, a pint and an half. Digest in a sand heat for three days; after which, strain off the tincture for use.

This tincture is principally employed for strengthening the gums, and in bleedings and scorbutic excretions of them: it may be fitted for use with these intentions, by mixing it with honey of roses, or the like. Some recommend it internally against scorbutic complaints, and as a corroborant in gleets, female weaknesses, &c. Its warmth, pungency, and manifestly astringent bitterish taste, point out its virtues in these cases to be considerable, though common practice among us has not yet received it.

Tincture of nux vomica. Roff.

Take of nux vomica, an ounce and a half; proof-spirit, two pounds. Digest for some days, and then strain it.

The nux vomica, a very active vegetable, has of late, as we have already had occasion to observe, been introduced into practice as taken internally, for the cure of intermittents and of contagious dysentery. In these affections it may be employed under the form of tincture as well as in substance; and in this way it most readily admits of being combined with other articles, either as adjuvantia or corrigentia.

Tincture of amber. Suec.

Take of yellow amber, powdered, one ounce; vitriolic ether, four ounces. Digest for three days in a vessel accurately closed, frequently shaking the vessel, and after this strain through paper.

The tincture of amber was formerly prepared with rectified spirit of wine: but the menstruum here directed gives a more complete solution, and forms a more elegant and active tincture. It possesses the whole virtues of the concrete; and although it has no place in our pharmacopoeia, yet it is perhaps to be considered as one of the most valuable preparations of amber. It has been recommended in a variety of affections, particularly those of the nervous kind, as hysterical and epileptic complaints. It may be taken from a few drops to the extent of a tea spoonful in a glass of wine or any similar vehicle. **Part II.**

**PHARMACY.**

**Chap. XXII. Mixtures.**

**Camphorated mixture. L.**

Take of camphor, one dram; rectified spirit of wine, ten drops; double-refined sugar, half an ounce; boiling distilled water, one pint. Rub the camphor first with the spirit of wine, then with the sugar; lastly, add the water by degrees, and strain the mixture.

While camphor is often exhibited in a solid state, it is frequently also advantageous to employ it as diffused in watery fluids. And with this intention the present formula is perhaps one of the most simple, the union being affected merely by the aid of a small quantity of spirit of wine and a little sugar. But perhaps the more common form of emulsion in which the union is effected, by triturating the camphor with a few almonds, is not to be considered as inferior to this. For the unctuous quality of the almonds serves in a considerable degree to cover the pungency of the camphor without diminishing its activity. Camphor under the present form as well as that of emulsion, is very often useful in fevers, taken to the extent of a tablespoonful every three or four hours.

**Chalk mixture. L.**

Take of prepared chalk, one ounce; double-refined sugar, six drams; gum-arabic, powdered, two ounces; distilled water, two pints. Mix them.

**Chalk-drink. E.**

Take of prepared chalk, one ounce; purest refined sugar, half an ounce; mucilage of gum-arabic, two ounces. Rub them together, and add by degrees, water, two pounds and an half; spirituous cinnamon water, two ounces.

These two preparations agree pretty much both in their name and in their nature. But of the two formulas that of the Edinburgh college is most agreeable to the palate, from containing a proportion of cinnamon water, by which the disagreeable taste of the chalk is taken off.

In the former edition of the Edinburgh pharmacopoeia, a preparation of this kind stood among the decoctions, and the chalk was directed to be boiled with the water and gum: by the present formula, the chalk is much more completely suspended by the mucilage and sugar; which last gives also to the mixture an agreeable taste. It is proper to employ the finest sugar, as the redundant acid in the coarser kinds might form with the chalk a kind of earthy salt. It would perhaps have been more proper to have added an aromatic, by suspending the entire powder of cinnamon, or its oil, by means of the mucilage and sugar. The method here directed is, however, less exceptionable in this than many other preparations, as the precipitated matter of the spirituous water will probably be inviscid in the saccharine and mucilaginous matter. This is a very elegant form of exhibiting chalk, and is a useful remedy in distastes arising from, or accompanied with, acidity in the prime viz. It is frequently employed in diarrhoea proceeding from that cause. The mucilage not only serves to keep the chalk uniformly dispersed, but also improves its virtues by breathing the internal surface of the intestines. The dose of this medicine requires no nicety. It may be taken to the extent of a pound or two in the course of a day.

**Musk mixture. L.**

Take of musk, two scruples; gum-arabic, powdered, double-refined sugar, of each one dram; rose-water, six ounces by measure. Rub the musk first with the sugar, then with the gum, and add the rose-water by degrees.

This had formerly the name of julepum e moscho, and was intended as an improvement upon the hysterical julep with musk of Bates. Orange-flower-water is directed by that author; and indeed this more perfectly coincides with the musk than rose-water: but as the former is difficultly procurable in perfection, the latter is here preferred. The julep appears turbid at first: on standing a little time, it deposits a brown powder, and becomes clear, but at the same time loses great part of its virtue. This inconvenience may be prevented by thoroughly grinding the musk with gum-arabic before the addition of the water: by means of the gum, the whole substance of the musk is made to remain suspended in the water. Volatile spirits are in many cases an useful addition to musk, and likewise enable water to keep somewhat more of the musk dissolved than it would otherwise retain.

**Almond milk. L.**

Take of sweet almonds, one ounce and an half; double-refined sugar, half an ounce; distilled water, two pints. Beat the almonds with the sugar; then, rubbing them together, add by degrees the water; and strain the liquor.

**Common emulsion. E.**

Take of sweet almonds, one ounce; bitter almonds, one dram; common-water, two pounds and a half. Beat the blanched almonds in a stone mortar, and gradually pour on them the common water, working the whole well together, then strain off the liquor.

**Arabic emulsion. E.**

This is made in the same manner as the preceding; only adding, while beating the almonds, of mucilage of gum arabic two ounces.

All these may be considered as possessing nearly the same qualities. But of the three the last is the most powerful demulcent.

Great care should be taken, that the almonds be not become rancid by keeping; which will not only render the emulsion extremely unpleasant, a circumstance of great consequence in a medicine that requires to be taken in large quantities, but likewise give it injurious qualities little expected from preparations of this class. The addition of the bitter almonds now ordered by the Edinburgh college in preparing these emulsions, may perhaps preserve them in some degree from suffering the above changes; but it is much more useful as giving the emulsion an agreeable flavour. And although the substance of bitter almonds be of a deleterious... Preparations and Compositions.

These liquors are principally used for diluting and obtunding acrimonious humours; particularly in heat of urine and stranguries arising either from a natural sharpness of the juices, or from the operation of cantharides and other irritating medicines: in these cases, they are to be drank frequently, to the quantity of half a pint or more at a time.

Some have ordered emulsions to be boiled, with a view to deprive them of some imaginary crudity; but by this process they quickly cease to be emulsions, the oil separating from the water, and floating distinctly on the surface. Acids and vinous spirits produce a like decomposition. On standing also for some days, without addition, the oily matter separates and rises to the top, not in a pure form, but like thick cream. These experiments prove the composition of the emulsions made from the oily seeds of kernels, and at the same time point out some cautions to be attended to in their preparation and use.

Ammoniacum milk. L.

Take of ammoniacum, two drams; distilled water, half a pint. Rub the gum resin with the water, gradually poured on, until it becomes a milk. In the same manner may be made a milk of asafoetida, and of the rest of the gum resins.

The ammoniacum milk is used for attenuating tough phlegm, and promoting expectoration, in humoral asthmas, coughs, and obstructions of the viscera. It may be given to the quantity of two spoonfuls twice a day.

The lac asafoetida is employed in spasmodical, hysterical, and other nervous affections. And it is also not unfrequently used under the form of injection. It answers the same purposes as asafoetida in substance.

Compound spirit of vitriolic ether. L.

Take of spirit of vitriolic ether, two pounds; oil of wine, three drams. Mix them.

This is supposed to be, if not precisely the same, at least very nearly, the celebrated mineral anodyne liquor of Hoffman; as we learn from his own writings, that the liquor which he thus denominated was formed of dulcified spirit of vitriol and the aromatic oil which arises after it, but he does not tell us in what proportions these were combined. It has been highly extolled as an anodyne and antispasmodic medicine; and with these intentions it is not unfrequently employed in practice.

Compound spirit of ammonia. L.

Take of spirit of ammonia, two pints; essential oil of lemon, nutmeg, of each two drams. Mix them.

This differs almost only in name from the following.

Volatile aromatic spirit, commonly called volatile oily spirit, and saline aromatic spirit. E.

Take of vinous spirit of sal ammoniac, eight ounces; distilled oil of rosemary, one dram and a half; distilled oil of lemon-peel, one dram. Mix them that the oils may be dissolved.

By the method here directed, the oils are as completely dissolved as when distillation is employed.

Volatile salts, thus united with aromatics, are not only more agreeable in flavour, but likewise more acceptable to the stomach, and less acrimonious than in their pure state. Both the foregoing compositions turn out excellent ones, provided the oils are good, and the distillation skilfully performed. The dose is from five or six drops to sixty or more.

Medicines of this kind might be prepared extemporaneously, by dropping any proper essential oil into the dulcified spirit of sal ammoniac, which will readily dissolve the oil without the assistance of distillation. But it is perhaps preferable that they should be kept in the shops ready mixed.

Sucinatated spirit of ammonia. L.

Take of alcohol, one ounce; water of pure ammonia, four ounces by measure; rectified oil of amber, one scruple; soap, ten grains. Digest the soap and oil of amber in the alcohol till they be dissolved; then add the water of pure ammonia, and mix them by shaking.

This composition is extremely penetrating, and has lately come into esteem, particularly for smelling to in lownesses and faintings, under the name of eau de luce. It has been hitherto brought from France. It is not quite limpid, for the oil of amber dissolves only imperfectly in the spirit: if the volatile spirit be not exceedingly strong, scarcely any of the oil will be imbibed.

The eau de luce is not only used with the view of making an impression on the nose, but is taken internally in the same cases. It has likewise of late been celebrated as a remedy for the bite of the rattlesnake, when used internally, and applied externally to the wounded part.

Camphorated spirit. L.

Take of camphor, four ounces; rectified spirit of wine, two pints: Mix them, so that the camphor may be dissolved.

Of this we have already had occasion to speak in the preceding chapter under the title given to it by the Edinburgh college.

Simple oily emulsion. Gen.

Take of almond oil, one ounce; syrup of althea, an ounce and a half; gum arabic, half an ounce; spring-water, six ounces. Mix, and make an emulsion according to art.

Volatile oily emulsion. Gen.

Take of almond oil, an ounce and a half; syrup of althea, one ounce; gum-arabic, half an ounce; volatile alkaline salt, one dram; spring-water, seven ounces. Mix them according to art.

Both these are elegant and convenient modes of exhibiting oil internally. And under these forms it is often advantageously employed in cases of cough, hoarseness, and similar affections. By means of the alkali, a more intimate union of oil with water is obtained than can be had with the intermediate either of syrup or vegetable mucilage; and in some cases, the the alkali both contributes to answer the intention in view, and prevents the oil from exciting sickness at stomach; But in other instances, the pungency which it imparts is disagreeable to the patient and unfavourable to the disease. According to these circumstances, therefore, where an oily mixture is to be employed, the practitioner will be determined in his choice to have recourse either to the one or the other formula.

**Acid julep. Gen.**

Take of weak vitriolic acid, three drams; simple syrup, three ounces; spring-water, two pounds. Mix them.

In this state, the vitriolic acid is sufficiently diluted to be taken with ease in considerable doses. And it may thus be advantageously employed in various affections; concerning which we have already had occasion to make a few remarks in Chemistry, no 617. (see Chemistry-Index), and which are to be answered, either by its action on the stomach, or on the system in general.

**Ether julep. Gen.**

Take of pure vitriolic ether, two scruples; spring-water, six ounces; refined sugar, half an ounce. Mix them according to art.

Although it is in general proper that ether should be diluted only when it is to be immediately used, yet it is sometimes necessary that it should be put into the hands of the patient in the state in which it is to be taken. In such instances the present formula is a very proper one; for the addition of a little mucilage tends both to cover the pungency of the ether in the mouth, and to retain it in a state of mixture with the water.

**Amber julep. Gen.**

Take of tincture of amber, two drams; refined sugar, half an ounce; spring-water, six ounces. Mix them according to art.

Under this form the tincture of amber is so far diluted and sweetened, as to form an agreeable mixture; and in this manner it may often be advantageously employed for counteracting nervous affections, and answering those other purposes for which we have already mentioned that this article is had recourse to in practice.

**Saline mixture, or julep. Succ.**

Take of fixed vegetable alkali, three drams; river-water, half a pound. To this lixivium add, lemon-juice, half a pound, or as much as is sufficient to saturate the alkali; syrup of black currants, one ounce.

This mixture is frequently prescribed in febrile diseases as a means of promoting a slight discharge by the surface: For where the skin is parched with great increased heat, it generally operates as a gentle diaphoretic. It often also promotes a discharge by the kidneys, and is not unfrequently employed to restrain vomiting. With these intentions it is in daily use among British practitioners, although it has no place in our pharmacopoeias, from its being entirely an extemporary prescription.

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**Mineral solution of arsenic.**

Take of white arsenic, reduced to a subtile powder, fixed vegetable alkali, each sixty-four grains; distilled water, half a pint. Put them into a flintstone flask, and let this be placed in a sand heat, so that the water may boil gently till the arsenic be completely dissolved; then add to the solution when cold half an ounce of spirit of lavender, and as much distilled water as to make the solution amount to a pint by measure, or fifteen ounces and an half by weight.

For the introduction of this remedy we are indebted to Dr Fowler of Stafford. We have already had occasion to mention it in our article Arsenic, no 14; see also Chemistry, no 1266, &c. In the former of these places we have observed, that if it be not precisely the same, it is at least supposed to be very analogous to a remedy which has had a very extensive sale in some parts of England under the name of the tafflefs ague drop; and which has been employed with very great success in the cure of obstinate intermittents. But whether the present formula in any degree approaches to the tafflefs ague drop or not, there can be no doubt, from the concurring testimony of many eminent practitioners, that it is equally successful in combating intermittents. For this purpose it is given according to the age and other circumstances of the patient in doses from two to twenty drops, once, twice, or oftener in the course of the day: And its use has been found to be attended with remarkable success, although with some patients even very small doses have been found to excite severe vomiting. Besides distinctly marked intermittents, this solution has also been sometimes successful in obstinate periodical headaches, and in cutaneous affections of the leprous kind, resisting every other mode of cure. And perhaps in every case where arsenic can be employed with safety or advantage internally, this preparation is preferable to any other with which we are yet acquainted.

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**Chap XXIII. Syrups.**

Syrups are saturated solutions of sugar, made in water, or watery or vinous infusions, or in juices. They were formerly considered as medicines of much greater importance than they are thought to be at present. Syrups and distilled waters were for some ages used as the great alteratives; insomuch that the evacuation of any peccant humour was never attempted till by a due course of these it had first been supposed to be regularly prepared for expulsion. Hence arose the exuberant collection of both, which we meet with in pharmacopoeias, and like errors have prevailed in each. As multitudes of distilled waters have been compounded from materials unfit to give any virtue over the helm; so numbers of syrups have been prepared from ingredients, which in this form cannot be taken in sufficient doses to exert their virtues; for two-thirds of a syrup consist of sugar, and greatest part of the remaining third is an aqueous fluid.

Syrups are at present chiefly regarded as convenient vehicles for medicines of greater efficacy; and used for sweetening draughts and juleps, for reducing the lighter powders into boluses, pills, or electuaries, and other similar purposes. Some likewise may not improperly be considered as medicines themselves; as those of saffron, buckthorn-berries, and some others.

To the chapter on Syrups the London college in their pharmacopoeia have prefixed the following general observations.

In the making of syrups, where we have not directed either the weight of the sugar, or the manner in which it should be dissolved, this is to be the rule:

Take of double-refined sugar, twenty-nine ounces; any kind of liquor, one pint. Dissolve the sugar in the liquor in a water-bath; then set it aside for twenty-four hours; take off the scum, and pour off the syrup from the feces if there be any.

The following are the general rules which have commonly been given with respect to the preparation of syrups.

I. All the rules laid down for making decoctions are likewise to be observed in the decoctions for syrups. Vegetables, both for decoctions and infusions, ought to be dry, unless they are expressly ordered otherwise.

II. In both the London and Edinburgh pharmacopoeias, only the purest or double refined sugar is allowed.

In the syrups prepared by boiling, it has been customary to perform the clarification with whites of eggs after the sugar had been dissolved in the decoction of the vegetable. This method is apparently injurious to the preparation; since not only the impurities of the sugar are thus discharged, but a considerable part likewise of the medicinal matter, which the water had before taken up from the ingredients, is separated along with them. Nor indeed is the clarification and depurification of the sugar, by itself, very advisable; for its purification by this process is not so perfect as might be expected: after it has undergone this process, the refiners still separate from it a quantity of oily matter, which is disagreeable to weak stomachs. It appears therefore most eligible to employ fine sugar for all the syrups; even the purgative ones (which have been usually made with coarse sugar, as somewhat coinciding with their intention) not excepted; for, as purgative medicines are in general ungrateful to the stomach, it is certainly improper to employ an addition which increases their offensive smell.

III. Where the weight of the sugar is not expressed, twenty-nine ounces are to be taken in every pint of liquor. The sugar is to be reduced into powder, and dissolved in the liquor by the heat of a water-bath, unless ordered otherwise.

Although in the formula of several of the syrups, a double weight of sugar to that of the liquor is directed, yet less will generally be sufficient. First, therefore, dissolve in the liquor an equal weight of sugar, then gradually add some more in powder, till a little remains undissolved at the bottom, which is to be afterwards incorporated by setting the syrup in a water-bath.

The quantity of sugar should be as much as the liquor is capable of keeping dissolved in the cold; if there is more, a part of it will separate, and concrete into crystals or candy; if less, the syrup will be subject to ferment, especially in warm weather, and change into a vinous or sour liquor. If in crystallizing, only the superfluous sugar be separated, it would be of no inconvenience; but when part of the sugar has candied, the remaining syrup is found to have an under proportion, and is as subject to fermentation as if it had wanted sugar at first.

IV. Copper-vessels, unless they be well tinned, should not be employed in the making of acid syrups, or such as are composed of the juices of fruits.

The confectioners, who are the most dexterous people at these kinds of preparations, to avoid the expense of frequently new-tinning their vessels, rarely make use of any other than copper ones untinned, in the preparation even of the most acid syrups, as of oranges and lemons. Nevertheless, by taking due care that their coppers be well scoured and perfectly clean, and that the syrup remain no longer in them than is absolutely necessary, they avoid giving it any ill taste or quality from the metal. This practice, however, is by no means to be recommended to the apothecary.

V. The syrup, when made, is to be set by till next day; if any saccharine crust appears upon the surface it is to be taken off.

Syrup of vinegar. E.

Take of vinegar, two pounds and an half; refined sugar, three pounds and an half. Boil them till a syrup be formed.

This is to be considered as simple syrup merely acidulated, and is by no means unpleasant. It is often employed in mucilaginous mixtures and the like; and on account of its cheapness it is often preferred to syrup of lemons.

Syrup of marshmallow.

Take of fresh root of marshmallow, bruised, one pound; double-refined sugar, four pounds; distilled water, one gallon. Boil the water with the marshmallow root to one half, and press out the liquor when cold. Set it by twelve hours; and, after the feces have subsided, pour off the liquor. Add the sugar, and boil it to the weight of six pounds. L.

Take of marshmallow roots, somewhat dried, nine ounces; water, ten pounds; purest sugar, four pounds. Boil the water with the roots to the consumption of one half, and strain the liquor, strongly expressing it. Suffer the strained liquor to rest till the feces have subsided; and when it is free from the dregs, add the sugar; then boil so as to make a syrup. E.

The syrup of marshmallows seems to have been a fort of favourite among dispensatory writers, who have taken great pains to alter and amend it, but have been wonderfully tender in retrenching any of its articles. In the last prescription, it is lost of its superfluities, without any injury to its virtues. It is used chiefly in nephritic cases, for sweetening emollient decoctions, and the like; of itself it can do little service, notwithstanding the high opinion which some have entertained of it; for what can be expected from two or three spoonfuls of the syrup, when the decoction, from which two or three pounds are made, may be taken at a draught or two? It is sometimes useful in tickling coughs. coughs, by invicating irritating matter distilling in the sauces: in this way it sometimes affords considerable relief.

**Syrup of clove July-flower.**

Take of fresh clove July-flowers, the heels being cut off, two pounds; boiling distilled water, six pints. Macerate the flowers for twelve hours in a glass vessel; and in the strained liquor dissolve double-refined sugar, that it may be made a syrup. L.

Take of clove July-flowers, fresh gathered and freed from the heels, one pound; purest sugar, seven pounds and a quarter; boiling water, four pounds. Macerate the flowers in the water for a night; then to the strained liquor add the sugar previously beat, and dissolve it by a gentle heat, to make the whole into a syrup. E.

This syrup is of an agreeable flavour, and a fine red colour; and for these it is chiefly valued. Some have substituted for it one easily preparable at seasons when the flowers are not to be procured: an ounce of clove spice is infused for some days in twelve ounces of white wine, the liquor strained, and, with the addition of twenty ounces of sugar, boiled to a proper consistence; a little cochineal renders the colour of this syrup exactly similar to that prepared from the clove July-flower; and its flavour is of the same kind, though not so pleasant. The abuse may be readily detected by adding to a little of the syrup some alkaline salt or ley; which will change the genuine syrup to a green colour; but in the counterfeit, it will make no such alteration, only varying the shade of the red.

As the beauty of the colour is a principal quality in this syrup, no force in the way of expression should be used in separating the liquor from the flowers.

**Syrup of colchicum. E.**

Take of colchicum root, fresh and succulent, cut into small pieces, one ounce; vinegar, fifteen ounces; purest sugar, twenty-five ounces. Macerate the root in the vinegar two days, now and then shaking the vessel; then strain it with a gentle pressure. To the strained liquor add the sugar, and boil a little, so as to form a syrup.

This syrup seems to be the best preparation of the colchicum; great care is required to take up this root in the proper season; and from errors of this kind we are to ascribe the uncertainty in the effects of this medicine as found in the shops.

The syrup of colchicum is often successfully employed as a diuretic, and may be taken from a dram or two to the extent of an ounce or more.

**Syrup of orange-peel.**

Take of fresh outer-rind of Seville-oranges, eight ounces; boiling distilled water, five pints. Macerate for twelve hours in a clove vessel; and in the strained liquor dissolve double-refined sugar to make a syrup. L.

Take of yellow rind of Seville orange peel fresh, six ounces; boiling water, three pounds. Infuse them for a night in a clove vessel; then strain the liquor; let it stand to settle; and having poured it off clear from the sediment, dissolve in it four pounds and a quarter of white sugar, so as to make it into a syrup with a gentle heat. E.

In making this syrup, it is particularly necessary that the sugar be previously powdered, and dissolved in the infusion with as gentle a heat as possible, to prevent the exhalation of the volatile parts of the peel. With these cautions, the syrup proves a very elegant and agreeable one, possessing great share of the fine flavour of the orange-peel.

**Syrup of saffron. L.**

Take of saffron, one ounce; boiling distilled water, one pint. Macerate the saffron, in the water, for twelve hours, in a clove vessel; and dissolve double-refined sugar in the strained liquor, that it may be made a syrup.

Saffron is very well fitted for making a syrup, as in this form a sufficient dose of it is contained in a reasonable compass. This syrup is at present frequently prescribed; it is a pleasant cordial, and gives a fine colour to juleps.

**Syrup of lemon-juice.**

Take of lemon-juice, strained, after the feces have subsided, two pints; double-refined sugar, fifty ounces. Dissolve the sugar, that it may be made a syrup. L.

Take of juice of lemons, suffered to stand till the feces have subsided, and afterwards strained, two pounds and a half; double-refined sugar, fifty ounces. Dissolve the sugar in the juice, so as to make a syrup. E.

**Syrup of mulberry-juice. L.**

**Syrup of raspberry juice. L.**

**Syrup of black currants. L.**

These three are directed by the London college to be prepared in the same manner as syrup of lemons, which immediately precedes them.

All these four are very pleasant cooling syrups; and with this intention they are occasionally used in draughts and juleps, for quenching thirst, abating heat, &c., in bilious or inflammatory distempers. They are sometimes likewise employed in gargarisms for inflammations of the mouth and tonsils.

**Syrup of the white poppy. L.**

Take of the heads of white poppies, dried, and the seeds taken out, three pounds and an half; double-refined sugar, six pounds; distilled water, eight gallons. Slice and bruise the heads, then boil them in the water, to three gallons, in a water-bath saturated with sea-salt, and press out the liquor. Reduce this by boiling to about the measure of four pints, and strain it while hot, first through a sieve, then through a thin woollen cloth, and set it aside for twelve hours, that the feces may subside. Boil the liquor, poured off from the feces, to three pints, and dissolve the sugar in it that it may be made a syrup.

**Syrup of white poppies, or of meconium, commonly called diacodium. E.**

Take of white poppy heads, dried, and freed from the feeds, two pounds; boiling-water, thirty pounds; purest sugar, four pounds. Macerate the bruised heads in the water for a night; next boil till only one-third part of the liquor remain; then strain it, expressing it strongly. Boil the strained liquor to the consumption of one half, and strain again; lastly, add the sugar, and boil to a syrup. It may also be made by dissolving in two pounds and a half of simple syrup, one dram of the extract of white poppies.

This syrup, impregnated with the opiate matter of the poppy heads, is given to children in doses of two or three drams; to adults from half an ounce to an ounce and upwards, for easing pain, procuring rest, and answering the other intentions of mild opiates. Particular care is requisite in its preparation, that it may be always made, as nearly as possible, of the same strength; and accordingly the colleges have been very minute in their description of the process.

Syrup of the red poppy. L.

Take of the fresh flowers of the wild or red poppy, four pounds; boiling distilled water, four pints and an half. Put the flowers by degrees into the boiling water in a water bath, constantly stirring them. After this, the vessel being taken out of the bath, macerate for twelve hours; then press out the liquor, and set it apart, that the feces may subside. Lastly, make it into a syrup, with double refined sugar.

The design of putting the flowers into boiling water in a water bath is, that they may be a little scalded, so as to shrink enough to be all immersed in the water; without this artifice they can scarcely be all got in; but they are no longer to be continued over the fire than till this effect is produced, lest the liquor become too thick, and the syrup be rendered ropy.

This syrup has been recommended in disorders of the breast, coughs, spitting of blood, pleurifies, and other diseases, both as an emollient and as an opiate. It is one of the lightest of the opiate medicines; and in this respect so weak, that some have doubted of its having any anodyne quality. We indeed presume, that it might be very safely superceded altogether; and accordingly it has now no place either in the Edinburgh pharmacopoeia, or some of the best foreign ones, though still retained by the London college.

Rose syrup. L.

Take of the dried leaves of the damask rose, seven ounces; double-refined sugar, six pounds; boiling distilled water, four pints. Macerate the rose leaves in water for twelve hours, and strain. Evaporate the strained liquor to two pints and an half, and add the sugar, that it may be made a syrup.

Syrup of pale roses. E.

Take of pale roses, fresh gathered, one pound; boiling water, four pounds; white sugar, three pounds. Macerate the roses in the water for a night; then to the liquor strained, and freed from the dregs, add the sugar; and boil them into a syrup.

This syrup may likewise be made from the liquor remaining after the distillation of rose-water depurated from its feces.

The liquor remaining after the distillation of roses (provided the still has been perfectly clean) is as proper for making this syrup as a fresh infusion; for the Compotis distillation only collects those volatile parts which are dissipated in the air while the infusion is boiling to its consistence. This syrup is an agreeable and mild purgative for children, in the dose of half a spoonful or a spoonful. It likewise proves gently laxative to adults; and with this intention may be of service in costive habits. Its principle use is in solutive glysters.

Syrup of dry roses. E.

Take of red roses, dried, seven ounces; white sugar, five pounds; boiling water, five pounds. Infuse the roses in the water for a night, then boil them a little; strain out the liquor, and adding to it the sugar, boil them to the consistence of a syrup.

This syrup is supposed to be mildly astringent; but is principally valued on account of its red colour. The London college have omitted it, having retained others at least equal to it in that respect.

Syrup of squills. E.

Take of vinegar of squills, two pounds; white sugar, three pounds and a half. Make them into a syrup with a gentle heat.

This syrup was formerly prepared with some spices, intended to alleviate the offensiveness of the squills. But while they had not this effect, they often counteracted the intention in view, and are therefore omitted. It is used chiefly in doses of a spoonful or two, for promoting expectoration, which it does very powerfully.

Simple or common syrup. E.

Take of purest sugar, fifteen parts; water, eight parts. Let the sugar be dissolved by a gentle heat.

This preparation is a plain liquid sweet, void of flavour or colour. It is convenient for sundry purposes where these qualities are not wanted, or would be exceptionable.

Syrup of buckthorn.

Take of the juice of ripe and fresh buckthorn berries, one gallon; ginger, bruised, one ounce; all spice, powdered, one ounce and an half; double-refined sugar, seven pounds. Set by the juice for some days, that the feces may subside, and strain. Macerate the ginger and all-spice in a pint of the strained juice for four hours, and strain. Boil away the rest of the juice to three pints; then add that part of the juice in which the ginger and all-spice have been macerated; and, lastly, the sugar, that it may be made a syrup.

Take of juice of the ripe buckthorn berries, depurated, seven pounds and a half; white sugar, three pounds and a half. Boil them to the consistence of a syrup. E.

Both these preparations, in doses of three or four spoonfuls, operate as brisk cathartics. The principal inconveniences attending them are, their being very unpleasing, and their occasioning a thirst and dryness of the mouth and fauces, and sometimes violent gripes. These effects may be prevented by drinking freely of water. water-gruel, or other warm liquids, during the operation. The ungratefulness of the buckthorn is endeavoured to be remedied in the first of the above prescriptions by the addition of aromatics, which, however, are scarcely sufficient for that purpose. The second also had formerly an aromatic material for the same intention, a dram of the essential oil of cloves; which being found ineffectual, is now rejected.

Syrup of balsam of Tolu. L.

Take of the balsam of Tolu, eight ounces; distilled water, three pints. Boil for two hours. Mix with the liquor, strained after it is cold, the double-refined sugar, that it may be made a syrup.

Balsamic syrup. E.

Take of simple syrup, just made, and warm from the fire, two pounds; tincture of balsam of Tolu, one ounce. When the syrup has grown almost cold, stir into it the tincture, by little at a time, agitating them well together till perfectly united.

This last method of making the balsamic syrup was dropped in one of the preceding editions of the Edinburgh pharmacopoeia, on a complaint that the spirit spoiled the taste of the syrup; which it did in a great degree when the tincture was drawn with malt-spirits, the nauseous oil which all the common malt spirits are accompanied with communicating that quality; and this was particularly the case when the spirituous part was evaporated from the syrup, as was directed in the former edition of the Edinburgh pharmacopoeia. Particular care therefore should be taken that the spirit employed for making the tincture be perfectly clean, and well rectified from all ill flavour.

The intention of the contrivers of the two foregoing processes seems to have been somewhat different. In the first, the more subtile and fragrant parts of the balsam are extracted from the grosser resinous matter, and alone retained in the syrup; the other syrup contains the whole substance of the balsam in larger quantity. They are both moderately impregnated with the agreeable flavour of the balsam.

In some pharmacopoeias a syrup of this kind is prepared from a tincture of balsam of Peru, with rose-water, and a proper quantity of sugar.

Syrup of violets.

Take of the fresh petals of the violet, two pounds; boiling distilled water, five pints. Macerate for 24 hours; afterwards strain the liquor, without pressing through thin linen. Add refined sugar, that it may be made a syrup. L.

Take of fresh violets, one pound; boiling water, four pounds; purest sugar, seven pounds and a half. Macerate the violets in the water for 24 hours in a glass, or at least a glazed earthen vessel, close covered; then strain without expression, and to the strained liquor add the sugar powdered, and make into a syrup. E.

This syrup is of a very agreeable flavour; and in the quantity of a spoonful or two proves to children gently laxative. It is apt to lose, in keeping, the elegant blue colour, for which it is chiefly valued; and hence some have been induced to counterfeit it with materials whose colour is more permanent. This abuse may be readily discovered, by adding to a little of the suspected syrup any acid or alkaline liquor. If the syrup be genuine, the acid will change its blue colour to a red, and the alkali will change it to a green; but if counterfeit, these changes will not happen. It is obvious, from this mutability of the colour of the violet, that the prescriber would be deceived if he should expect to give any blue tinge to acidulated or alkalized juleps or mixtures by the addition of the blue syrup.

Syrup of ginger.

Take of ginger, bruised, four ounces; boiling distilled water, three pints. Macerate for four hours, and strain; then add refined sugar, that it may be made a syrup. L.

Take of powdered ginger, three ounces; boiling water, four pounds; purest sugar, seven pounds and a half. Macerate the ginger in the water in a clothe vessel for 24 hours; then to the liquor, strained and freed from the feces, add the powdered sugar, and make them into a syrup. E.

These are agreeable and moderately aromatic syrups, lightly impregnated with the flavour and virtues of the ginger.

Acid of syrup. Gen.

Take of weak spirit of vitriol, two drams; syrup of lemons, six ounces. Mix them.

Where we wish to obtain a syrup, not only strongly acidulated, but also powerfully astringent, this formula may be considered as well suited to answer the purpose.

Alkaline syrup. Gen.

Take of salt of tartar, three drams; simple syrup, six ounces. Mix them.

In this syrup we have in some degree the converse of the preceding; and it may be usefully employed either for the destruction of acid in the stomach, or for the formation of neutral or effervescing mixtures.

Syrup of garlic. Suec.

Take of the fresh root of garlic, sliced, one pound; boiling water, two pounds. Macerate them in a clothe vessel for an hour. Add to the strained liquor, refined sugar, two pounds. Boil them to a syrup.

This syrup formerly held a place in our pharmacopoeias, and was recommended for promoting expectoration in cases of chronic catarrh and other affections of the breast; but, as well as the oxymel of garlic, it is now banished from them; and there can be little doubt that the same intentions may in general be answered by less disagreeable medicines. Yet where we wish to employ garlic in a watery menstruum, this formula is perhaps one of the best under which it can be exhibited.

Syrup of almonds. Suec.

Take of sweet almonds, one pound; bitter almonds, two drams. Let the almonds be blanched and beat in a stone mortar with a wooden pestle; then by degrees add barley-water, two pounds; strain the liquor, liquor, and form it into a syrup, with as much double-refined sugar as may be necessary.

The agreeable flavour of the almonds is in this formula communicated to a syrup, which may be advantageously employed to sweeten mixtures, or to form a pleasant drink when diffused in water; and the flavour is not a little improved by the addition of the proportion of bitter almonds here directed. But even these cannot be supposed to communicate any active quality to this syrup, as they are employed in so small a quantity: and still less is to be expected from the sweet almonds, which can communicate little more to the syrup than their mild oil.

**Syrup of cinnamon. Roff.**

Take of cinnamon, bruised, five ounces; spirituous cinnamon water, two pounds. Digest them in a close glass vessel for 24 hours; then add to the strained liquor double refined sugar, three pounds. Boil it to a syrup.

This syrup is strongly impregnated with the cinnamon; and where we wish to sweeten any mixture, at the same time adding to it an agreeable aromatic, it is perhaps one of the best articles we can employ.

**Emetic syrup. Brun.**

Take of glafs of antimony, finely powdered, two drams; Rhenish wine, twelve ounces. Let them be digested for three days in a gentle heat; then strain the liquor through paper, and mix with the strained liquor 30 ounces of double-refined sugar. Let it be formed into a syrup, and kept in a close vessel.

There can be no doubt of this syrup being strongly impregnated with the emetic quality of the antimony; and it will at least have so far the advantage of being very agreeable to the taste, that it may be readily taken by very young people. But every good effect to be obtained from it may be had with more certainty, by adding to simple syrup any quantity that may be thought necessary of the antimonial tartar previously dissolved in a small proportion of water.

**Syrup of quicksilver. Suec.**

Take of purified quicksilver, one dram; gum arabic, three drams; rose-water, as much as sufficient for reducing the gum to a mucus. Let them be rubbed in a mortar till the quicksilver totally disappears; then by degrees mix with it simple syrup, four ounces.

In this we have a preparation similar to the mercurial solution of Dr Plenck formerly mentioned; and which, while it does not possess any other advantage than mere sweetness of taste, is liable to the objections formerly urged against that preparation.

**Chap. XXIV. Medicated Honeys.**

The more fixed parts of vegetables, dissolved in watery liquors, may be thence transferred into honey, by mixing the honey with the watery decoction or juice of the plant, and boiling them together till the aqueous part has exhaled, and the honey remains of its original consistence. Honey has not probably, however, any very peculiar advantage over sugar, and preparations from it are liable to many inconveniences which sugar is free from: in particular, it is much more liable to run into fermentation, and in many constitutions produces gripes, and often violent effects. The Edinburgh college have therefore rejected the whole of the oxymels from their last edition of the pharmacopoeia. And the number of preparations with honey in most of the foreign pharmacopoeias is now much diminished. Still, however, there are several much employed by practitioners of eminence; and of course retained in the London pharmacopoeia.

**Honey of roses. L.**

Take of dried red rose-buds, with the heels cut off, four ounces; boiling distilled water, three pints; clarified honey, five pounds. Macerate the rose leaves in the water for six hours; then mix the honey with the strained liquor, and boil the mixture to the thickness of a syrup.

This preparation is not unfrequently used as a mild cooling detergent, particularly in gargarisms for ulcerations and inflammation of the mouth and tonsils. The rose-buds here used should be hastily dried: the design of doing so is, that they may the better preserve their astringency.

**Honey of squills. L.**

Take of clarified honey, three pounds; tincture of squills, two pints. Boil them in a glass vessel to the thickness of a syrup.

The honey will here be impregnated with all the active parts of the squills which the tincture before contained, and may be employed as an useful expectorant or diuretic.

**Oxymel of verdigrife. L.**

Take of prepared verdigrife, one ounce; vinegar, seven ounces; clarified honey, fourteen ounces. Dissolve the verdigrife in the vinegar, and strain it through linen; then add the honey, and boil the whole to a proper thickness.

This is an improvement of what was formerly known in our pharmacopoeias under the title of mel Ægyptiacum; which, however, was, as then prepared, very uncertain with respect to strength. It is used only externally for cleansing foul ulcers, and keeping down fungous flesh. It is also often serviceable in venereal ulcerations of the mouth and tonsils. But there is some danger from its application to places from the situation of which it is apt to be swallowed; for even a small quantity of verdigrife passing into the stomach may be productive of distressing, if not deleterious, effects.

**Oxymel of meadow saffron. L.**

Take of the fresh root of meadow-saffron, cut into thin slices, one ounce; distilled vinegar, one pint; clarified honey, two pounds. Macerate the root of meadow-saffron with the vinegar, in a glass vessel, with a gentle heat, for 48 hours. Strain the liquor, pressed out strongly from the root, and add the honey. Lastly, boil the mixture, frequently stirring it with a wooden spoon, to the thickness of a syrup. This oxymel may be considered as very analogous to the syrup of colchicum, of which we have already made some observations. Under this form it was first introduced by Dr Stoerck. And although with certain constitutions the syrup is unquestionably preferable, yet it well deserves a place in our pharmacopoeias, as being an active medicine.

**Oxymel of squills. L.**

Take of clarified honey, three pounds; vinegar of squills, two pints. Boil them in a glass vessel, with a slow fire, to the thickness of a syrup.

The honey was formerly employed for this preparation unclarified, and the scum, which in such cases arises in the boiling, taken off: by this means the impurities of the honey were discharged; but some of the medicinal parts of the squills, with which the vinegar was impregnated, were also separated. For this reason the college of London have now judiciously ordered the honey for all these kinds of preparations to be previously clarified by itself.

Oxymel of squills is an useful aperient, detergent, and expectorant, and of great service in humoral asthmas, coughs, and other disorders where thick phlegm abounds. It is given in doses of two or three drams, along with some aromatic water, as that of cinnamon, to prevent the great nausea which it would otherwise be apt to excite. In large doses it proves emetic.

**Simple oxymel. L.**

Take of clarified honey, two pounds; distilled vinegar, one pint. Boil them in a glass vessel, with a slow fire, to the thickness of a syrup.

This preparation may be considered as analogous to the *syrupus acetii* of the Edinburgh pharmacopoeia. It is not inferior in efficacy to many more elaborate compositions. It is an agreeable, mild, cooling medicine. It is often used in cooling detergent gargarisms, and not unfrequently as an expectorant.

**Oxymel of garlic. Dan.**

Take of garlic, cut in slices, an ounce and a half; caraway seeds, sweet fennel seeds, each two drams; clarified honey, ten ounces; vinegar, half a pint. Boil the vinegar for a little time, with the seeds bruised, in a glazed earthen vessel; then add the garlic, and cover the vessel close; when grown cold, press out the liquor, and dissolve in it the honey by the heat of a water bath.

This oxymel is recommended for attenuating viscid juices, promoting expectoration, and the fluid secretions in general. It is doubtless a medicine of considerable efficacy, though very unpleasant, the flavour of the garlic prevailing notwithstanding the addition of the aromatic seeds.

**Pectoral oxymel. Brun.**

Take of elecampane roots, one ounce; orris root, half an ounce; gum ammoniac, one ounce; vinegar, half a pint; clarified honey, one pound; water, three pints. Let the roots, cut and bruised, be boiled in the water till one-third is wasted; then strain off the liquor; let it stand to settle; and having poured it off clear from the feces, add to it the honey and the ammoniac, previously dissolved in the vinegar. Mix them together, by gently boiling them.

The title of this composition expresses its medical virtues. It is designed for those disorders of the breast that proceed from a load of viscid phlegm, and obstructions of the pulmonary vessels. Two or three spoonfuls may be taken every night and morning, and continued for some time.

---

**CHAP. XXV. Powders.**

This form receives such materials only as are capable of being sufficiently dried to become pulverifiable without the loss of their virtue. There are many substances, however, of this kind, which cannot be conveniently taken in powder: bitter, acrid, fetid drugs, are too disagreeable; emollient and mucilaginous herbs and roots are too bulky; pure gums cohere, and become tenacious in the mouth; fixed alkaline salts liquefy on exposing the composition to the air; and volatile alkalis exhale. Many of the aromatics, too, suffer a greater loss of their odorous principle when kept in powder; as in that form they no doubt expose a much larger surface to the air.

The dose of powders, in extemporaneous prescription, is generally about half a dram: it rarely exceeds a whole dram, and is not often less than a scruple. Substances which produce powerful effects in smaller doses are not trusted to this form, unless their bulk be increased by additions of less efficacy; those which require to be given in larger ones are better fitted for other forms.

The usual vehicle for taking the lighter powders is any agreeable thin liquid. The ponderous powders, particularly those prepared from metallic substances, require a more consistent vehicle, as syrups; for from thin ones they soon fall-side. Resinous substances likewise are most commodiously taken in thick liquors; in thin ones they are apt to run into lumps, which are not easily again soluble.

**General rules for making powders.**

I. Particular care ought to be taken that nothing carious, decayed, or impure, be mixed in the composition of powders: the stalks and corrupted parts of plants are to be separated.

II. The dry aromatics ought to be sprinkled, during their pulverization, with a few drops of any proper water.

III. The moister aromatics may be dried with a very gentle heat before they are committed to the mortar.

IV. Gums, and such other substances as are difficultly pulverifiable, should be pounded along with the drier ones, that they may pass the sieve together.

V. No part should be separated for use until the whole quantity put into the mortar has passed the sieve, and the several siftings mixed together; for those parts of the subject which are first powdered may prove different, at least in degree of efficacy, from the rest.

VI. Powders of aromatics are to be prepared only in small quantities at a time, and kept in glass vessels very closely stopped.

If powders are long kept, and not carefully secured from the air, their virtue is in a great measure destroyed, although... although the parts in which it consists should not in other circumstances prove volatile. Thus, though the virtues of ipecacuanha are so fixed as to remain entire even in extracts made with proper menstrua, yet if the powdered root be exposed for a long time to the air, it loses its emetic quality.

**Aloetic powder. L.**

Take of socotrine aloes, one pound; white canella, three ounces. Rub them separately to powder, and then mix them.

This composition has long been known in the shops under the title of hiera pica. It furnishes us with an useful aloetic purgative, the canella operating as a good corrigent for the aloes. But it is more frequently employed as the basis of electuaries or pills, or of a tincture which was for a long time distinguished by the appellation of sacred tincture.

**Aloetic powder with iron. L.**

Take of socotrine aloes, powdered, an ounce and an half; myrrh, powdered, two ounces; dry extract of gentian, vitriolated iron, of each, in powder, one ounce. Mix them.

In this powder we have an aloetic and chalybeate combined. It consists of nearly the same articles which formerly entered the composition of the pilulae cephaliticae chalybeatae, as they were called; and it is perhaps more frequently employed when brought to the form of pills by means of syrups than in powder; but in either way it is an useful medicine, and is particularly employed with advantage in cases of obstructed menstruation.

**Aloetic powder with guaiacum. L.**

Take of socotrine aloes, one ounce and an half; gum guaiacum, one ounce; aromatic powder, half an ounce. Rub the aloes and gum guaiacum separately to powder; then mix all the ingredients together.

In the guaiacum, as well as the aloes, we have a warm gummi-resinous purgative; and both are corrected, as well as more minutely divided, from their combination with the aromatics. This therefore furnishes us with an useful purgative; but when taken only in small doses, its chief effect is that of promoting perspiration. It is, however, more frequently employed in the form of pills than in the state of powder; and indeed it consists of nearly the same ingredients which constituted the pilula aromatica of the former edition of the London pharmacopoeia.

**Aromatic powder. L.**

Take of cinnamon, two ounces; smaller cardamom seeds hulled, ginger, long pepper, of each one ounce. Rub them together to a powder.

**Aromatic powder, or aromatic spices. E.**

Take of nutmegs, lesser cardamom seeds, ginger, each two ounces. Beat them together into a powder, to be kept in a phial well shut.

Both these compositions are agreeable, hot, spicy medicines; and as such may be usefully taken in cold phlegmatic habits and decayed constitutions, for warming the stomach, promoting digestion, and strengthening the tone of the visera. The dose is from ten prejara grains to a scruple and upwards. The first is considerably the warmest. This principally arises from the quantity of long pepper which it contains. But it is perhaps to be doubted whether from this article any advantage be derived; and a powder not inferior to either might, we think, be formed, by substituting cassia for the cinnamon employed by the one college, or the nutmegs by the other.

**Compound powder of asarabacca. L.**

Take of the dry leaves of asarabacca, sweet marjoram, Syrian herb mafich, dry flowers of lavender, each one ounce. Powder them together.

**Sternutatory or cephalic powder. E.**

Take of the leaves of asarum, three parts; marjoram, one part. Beat them together into a powder.

Though the former of these powders be more compounded than the latter, yet they differ very little. They are both agreeable and efficacious rhinines, and superior to most of those usually sold under the name of herb snuff. They are often employed with great advantage in cases of obstinate headache, and of ophthalmias resisting other modes of cure. Taken under the form of snuff to the extent of five or six grains at bed-time, they will operate the succeeding day as a powerful rhinine, inducing frequent sneezing, but still more a large discharge from the nose. It is, however, necessary, during their operation, to avoid exposure to cold.

**Powder of ceruse. L.**

Take of ceruse, five ounces; farocoll, one ounce and an half; tragacanth, half an ounce. Rub them together into powder.

This composition is the tre-bisi albi of Rhazes brought back to its original simplicity with regard to the ingredients, and without the needless trouble of making it into troches. It is employed for external purposes, as in collyria, lotions, and injections, for repelling acrimonious humours, and in inflammations.

**Compound powder of crabs claws. L.**

Take of crabs claws, prepared, one pound; chalk, red coral, each, prepared, three ounces. Mix them.

These powders have lost several of their ingredients without any injury to their virtues; and possibly they would still bear a farther reduction, for the crabs eyes and chalk are by themselves as least as effectual as any composition of them with coral. And perhaps every purpose to be obtained from them may be accomplished by a more simple absorbent, as the chalk powder afterwards to be mentioned, or the powder of the lapilli cancrorum.

**Compound powder of contrayerva. L.**

Take of contrayerva, powdered, five ounces; compound powder of crabs claws, one pound and an half. Mix them.

This powder was formerly directed to be made up into balls with water, and was then called lapis contra- yerva; a piece of trouble now laid aside as needless, for it was necessary to reduce the balls into powder again. again before they could be used. Nor did that form contribute, as has been imagined, to their preservation; for it is scarcely to be supposed that the powder will lose more by being kept for a reasonable length of time in a close-stopped glass than the balls will in the humecation with water and evaporation in the air before they are fit for being put by to keep. This medicine has much better claim to the title of an alexipharmaic and sudorific than the foregoing compositions. The contraryerva by itself proves very serviceable in low fevers, where the vis vitae is weak, and a diaphoresis is to be promoted. It is possible that the crab's claws are of no farther service than as they divide this powerful ingredient, and make it fit more easily on the stomach.

**Compound powder of chalk. L.**

Take of prepared chalk, half a pound; cinnamon, four ounces; tormentil, gum-arabic, of each three ounces; long pepper, half an ounce. Powder them separately, and mix them.

**Chalk powder. E.**

Take of white chalk, prepared, four ounces; nutmeg, half a dram; cinnamon, one dram. Mix and make them into a powder; which may supply the place of the cardialgic troches.

The addition of the aromatics in the above formula coincides with the general intention of the remedy which is indicated for weakness and acidity in the stomach; and in looseness from acidity.

**Compound powder of chalk with opium. L.**

Take of compound powder of chalk, eight ounces; hard purified opium, powdered, one dram and an half. Mix them.

From the addition of the opium this remedy becomes still more powerful than the above in restraining diarrhea.

**Compound powder of ipecacuanha. L.**

Take ipecacuanha and hard purified opium, of each, powdered, one dram; vitriolated kali, powdered, one ounce. Mix them.

**Sudorific, or Dover's powder. E.**

Take of vitriolated tartar, three drams; opium, root of ipecacuanha powdered, of each one scruple. Mix, and grind them accurately together, so as to make an uniform powder.

The vitriolated tartar, from the grittiness of its crystals, is perhaps better fitted for tearing and dividing the tenacious opium than any other salt; this seems to be its only use in the preparation. The operator ought to be careful that the opium and ipecacuanha shall be equally diffused through the whole mass of powder, otherwise different portions of the powder must have differences in degree of strength.

The hard purified opium, directed by the London college, is, from this circumstance, preferable to opium in its ordinary state, employed by the Edinburgh college.

This powder is one of the most certain sudorifics that we know of; and as such, was recommended by Dr. Dover as an effectual remedy in rheumatism. Modern practice confirms its reputation, not only in rheumatism, but also in dropsy and sundry other diseases, where it is often difficult by other means to produce a copious sweat. The dose is from five to ten or twelve grains, according as the patient's stomach and strength can bear it. It is convenient to avoid much drinking immediately after taking it, otherwise it is very apt to be rejected by vomiting before any other effects are produced.

**Compound powder of jalap. E.**

Take of jalap root, one ounce; crystals of tartar, two ounces. Mix, and diligently grind them together for some time, so as to form a very fine powder.

The use of the crystals in this preparation is to break down and divide the jalap into very minute particles, whereby its operation is thought to be meliorated; and on this account the two articles are directed to be pounded together, and not separately. But whether from this circumstance any advantage arises or not, there can be no doubt that this combination furnishes us with a very useful and active purgative, in every case where it is necessary to produce both a full evacuation of the intestinal canal, and a free discharge from the system in general, under the form of catharsis.

**Compound powder of myrrh. L.**

Take of myrrh, dried savin, dried rue, Russian castor, of each, one ounce. Rub them together into a powder.

This is a reformation of the troches of myrrh, a composition contrived by Rhazes against uterine obstructions. It may be taken in any convenient vehicle, or made into boluses, from a scruple to a dram or more, two or three times a-day.

**Opiate powder. L.**

Take of hard purified opium, powdered, one dram; burnt and prepared hartshorn, nine drams. Mix them.

The hartshorn is here intended merely to divide the opium, and to give it the form of powder, although it may perhaps have also some influence in rendering the opium more active from destroying acid in the stomach. But whether in this way it has any effect or not, there can be no doubt that it is a very convenient formula for the exhibition of opium in powder; which on some occasions is preferable to its being given either in a liquid form or in that of pills. As ten grains of this powder contain precisely one of the opium, the requisite dose may be easily adapted to the circumstances of the case. It is often successfully employed as a sweating powder; and has not, like Dover's powder, the effect of inducing sickness or vomiting.

**Compound powder of scammony.**

Take of scammony, hard extract of jalap, each two ounces; ginger, half an ounce. Powder them separately, and mix them. Take of scammony, crystals of tartar, each two ounces; mix, and grind them diligently into a powder. E.

It is much to be regretted, that in the pharmacopoeias published by authority in Britain, two compositions should be distinguished by the same name, differing considerably from each other in their nature and degree of activity.

The compound powder of scammony in the last edition of the London pharmacopoeia differed considerably from the present: For there, the only addition was calcined hartshorn, intended merely for the division of the scammony. This purpose is still better answered by the crystals of tartar, which at the same time confine with the operation of the scammony as a purgative. But the addition of jalap and ginger, according to the present formula of the London pharmacopoeia, gives not only a purgative considerably different, but increases also the heating quality of the medicine, while the cream of tartar has an evident refrigerant power. Both may on occasions be useful, but we think that in most cases the Edinburgh formula will be found preferable.

In editions of our pharmacopoeias of still older date, this powder was prepared with another very active ingredient, diaphoretic antimony. It was much celebrated as distinguished by the name of its inventor, being called from its first publisher, Cornachini's powder. In a former edition of the Edinburgh pharmacopoeia it was thus directed to be prepared:

Take of diaphoretic antimony, cream of tartar, scammony, each equal parts. Make them into a powder.

This may be given to the quantity of a dram or more. In other prescriptions, the tartar and antimonial calx bear nearly the same proportion to the scammony as the calcined hartshorn did in the London pharmacopoeia. It appears probable, that neither of these ingredients are of any farther use, than as they divide the texture of the scammony; though Cornachini supposes very considerable advantage from some deobstruent quality in the tartar, whereby the vessels shall be opened, and the noxious humours prepared for expulsion; and from the preparation of antimony, though it have no sensible operation, he expects some share of the same succeds which sometimes attends the rougher preparations of that mineral.

Both the present formulas may, however, be considered as possessing all the advantages of Cornachini's powder.

Powder of scammony with aloes. L.

Take of scammony, six drams; hard extract of jalap, focotarine aloes, of each an ounce and an half; ginger, half an ounce. Powder them separately, and mix them.

In this formula, the combination of scammony, jalap, and aloes, furnishes a very active purgative, which, with some intentions at least, may be preferable to either of the preceding. Taken from five to ten grains, it will operate as a purgative, even in cases of obstinate coliciveness.

Powder of scammony with calomel. L.

Take of scammony, half an ounce; calomel, double-refined sugar, of each two drams. Rub them separately to a powder, and then mix them.

In this formula, we have the scammony in a more simple state, united with such a proportion of calomel as must very considerably aid its purgative power. And accordingly it may be employed with advantage, both in cases of obstinate coliciveness and in drophical affections, where a considerable discharge is required from the system.

Compound powder of senna. L.

Take senna, crystals of tartar, of each two ounces; scammony, half an ounce; ginger, two drams. Rub the scammony by itself, rub the rest together into a powder, and then mix them all.

This powder is given as a cathartic, in the dose of two scruples or a dram. The spice is added, not only to divide, but to warm the medicine, and make it fit easier on the stomach. The scammony is used as a stimulus to the senna; the quantity of the latter necessary for a dose, when not assisted by some more powerful material, being too bulky to be conveniently taken in this form.

The composition of this medicine is now considerably simplified by the rejection both of cinnamon and cloves, as the ginger alone is found fully to answer the intention in view.

Styptic powder. E.

Take of alum, an ounce and an half; gum-kino, three drams. Grind them together into a fine powder.

In former editions of our pharmacopoeia, a powder of this kind was directed to be made with alum and dragon's blood, and was long in repute as an astringent, under the title of Helvetius's styptic powder. The gum-kino is judiciously substituted for the dragon's blood, as being a much more powerful and certain astringent. The chief use of this powder is in hemorrhagies, especially of the uterus.

Compound powder of tragacanth. L.

Take of tragacanth powdered, gum-arabic, starch, each an ounce and a half; double-refined sugar, three ounces. Rub them together into a powder.

This composition is somewhat simplified by the rejection of the marshmallow, and liquorice-root, which formerly entered it. But this has not probably produced any diminution of its medical properties. It operates as a mild emollient; and hence becomes serviceable in hectic cases, tickling coughs, strangury, some kinds of alvine fluxes, and other disorders proceeding from a thin acrimonious state of the humours, or an abrasion of the mucus of the intestines; they soften, and give a greater degree of consistency to the former, and defend the latter from being irritated or excoriated by them. All the ingredients coincide in these general intentions. The dose is from half a dram to two or three drams, which may be frequently repeated.

Anthelmintic powder. Gen.

Take of the flowers of tanfy, worm-seeds, each three drams; sal martis, one dram. Mix them. Both the tanfly and worm-feeding possess a considerable degree of anthelmintic power, which is not a little increased by the salt of steel. And from this combination more effect in the expulsion of worms, particularly of the lumbrici, may be expected, than from any of the articles taken by themselves. This powder may be taken to the extent of half a dram or upwards for a dose, proportioned to the age and circumstances of the patient.

Powder against the bite of a mad dog. Brun.

Take of ash-coloured ground liverwort, two ounces; black pepper, one ounce. Beat them together into a powder.

The virtue for which this medicine has been celebrated, is expressed in its title; the dose is a dram and a half, to be taken in the morning fasting, in half a pint of cows milk warm, for four mornings together.

At one period it was held, on the recommendation of Dr Mead and other eminent practitioners, in very high esteem. Now, however, it has fallen into such disrepute, as to be banished from most of the modern pharmacopoeias.

Compound powder of arum. Suec.

Take of arum root, fresh dried, two drams; yellow water-flag roots, burnt saxifrage roots, each one dram; white canella, a dram; salt of wormwood, one scruple. Beat them into a powder, which is to be kept in a close vessel.

In former editions of the London pharmacopoeia, one of the ingredients in this composition was called acorus vulgaris or vulgaris; a name which has been applied, by different writers, both to calamus aromaticus, and to gladiolus luteus, or common yellow water-flag. In this uncertainty, the compounders generally took the former. But as the medicine was first contrived by a German physician (Birkmann), and as in some of the German pharmacopoeias, the acorus vulgaris is explained to be the water-flag, the Swedish college have rather, in conformity to the original prescription, than from any opinion of the virtues of the water flag (which appears, when the root is dried and powdered, to be very inconsiderable), made choice of this last, and expressed it by the name which more clearly distinguishes it from the other. The caution of keeping the powder in a close vessel is very necessary; for if it be exposed to the air, the alkaline salt, imbibing moisture, would run into a liquid state. Two alkaline salts have been generally directed; but as they differ from each other only in name, one of them is here justly omitted, and supplied by a proportional increase of the other. Crabs eyes were originally an article in this composition, but probably served little other purpose than to increase its volume.

Agreeably to the above remark, the college of Edinburgh, in a revival of their pharmacopoeia, had omitted the crabs-eyes, and continued the former practice of using calamus aromaticus for the acorus vulgaris. They had likewise exchanged the cinnamon for the white canella; and the alkaline salt for a neutral one, better suited to the form of a powder. Their formula was as follows:

Take of arum roots, newly dried, two ounces; calamus aromaticus, burnt saxifrage roots, each one ounce; white canella, six drams; vitriolated tartar, two drams. Mix and make them into a powder.

This article, which had formerly a place also in the London pharmacopoeia, is still retained in some of the best foreign ones; but it is now altogether rejected from our pharmacopoeias.

The compound powder of arum was originally intended as a stomachic: and in weaknesses and relaxations of the stomach, accompanied with a surcharge of viscid humours, it is doubtless a very useful medicine. It frequently has also good effects in rheumatic cases: the dose may be from a scruple to a dram, two or three times a day, in any convenient liquor. It should be used as fresh as possible, for its virtue suffers greatly in keeping; the arum root in particular, its capital ingredient, soon loses the pungency, in which its efficacy principally consists.

Dysenteric powder. Suec.

Take of bitter purging salts, rhubarb, each equal parts. Mix them.

In this composition, the salt will bristen the operation of the rhubarb as a cathartic, and the astrinency of the latter will tend to increase the tone of the stomach; hence, in consequence of evacuating, and at the same time strengthening the alimentary canal, it may be presumed to have considerable influence in promoting digestion.

Dysenteric powder. Dan.

Take of rhubarb, one ounce; calcined hartshorn, half an ounce; gum-arabic, three drams; cascara bark, two drams. Mix them, and reduce them to a very fine powder.

Here the rhubarb is combined with another powerful tonic, the cascara; and while the calcined hartshorn serves to neutralize acid, the gum-arabic will operate as a demulcent. This composition therefore may be very useful in dysenteric cases, after the violence of the disease has been overcome, and when there remains a debilitated and abraded state of the intestinal canal.

Fumigation powder. Ross.

Take of olibanum, amber, myrrh, each three parts; storax, two parts; benzoin, labdanum, each one part. Mix them into a groat powder.

This powder is intended for the purpose of fumigation; and when burnt it gives out a fragrant odour; hence it may be successfully employed for combating disagreeable smells, and counteracting putrid or other noxious vapours diffused in the atmosphere.

Powder for infants. Suec.

Take of magnesia alba, one ounce; rhubarb, reduced to a very fine powder, one dram. Let them be mixed.

This powder is very useful for destroying acid, and at the same time restoring the diminished tone of the alimentary canal; hence it is often advantageously employed in cases of diarrhoea, which depend on these morbid morbid conditions. And it is in general a circumstance of considerable advantage, that it does not tend to check loofeefes very suddenly. It is particularly useful with infants, and hence the origin of the name here affixed to it.

Nitrous powder. Suec.

Take of purified nitre, three ounces; salt of forrel, one ounce; double-refined sugar, ten ounces. Let them be mixed.

This is a very convenient and agreeable form of exhibiting nitre: for while the sugar serves not only to divide and diffuse it, but also to correct its taste, the salt of forrel adds to its refrigerant power.

Purging Peruvian powder. Gen.

Take of the powder of Peruvian bark, one ounce; powder of rhubarb, powder of sal ammoniac, each one dram and a half.

It has been imagined by many, that particular advantage resulted from uniting the Peruvian bark with sal ammoniac; and there can be no doubt, that in some cases inconvenience results from the bark, in consequence of its binding the belly. There are therefore circumstances in which the combination here proposed may perhaps be proper: but there is reason to believe that the benefit of the sal ammoniac is more imaginary than real; and it not unfrequently happens, that we are disappointed of the benefit which might otherwise be derived from the bark, in consequence of its proving even of itself a purgative. Hence, in perhaps a majority of cases, the exhibiting it with the additions here proposed will be rather prejudicial than otherwise.

Thebaic powder. Suec.

Take of opium, half a scruple; purified nitre, five scruples and a half; refined sugar, one ounce. Mix them together into a powder.

In this powder those inconveniences which sometimes result from opium may with certain constitutions be corrected, in consequence of the refrigerant power of nitre; and hence it may prove a very useful sedative powder. The sugar is intended merely to give form to the medicine; and in its state of combination, each dram of it contains a grain of opium; so that a practitioner has it in his power easily to regulate the dose according to circumstances.

Sponge-powder. Gen.

Take of burnt sponge, powdered, common salt, each three drams. Mix them, and divide into twelve powders.

We have formerly noticed the manner of burning sponge, (see No. 98.) It is of very considerable service in scorfulous affections, and particularly in the cure of the bronchocele. It has of late been highly celebrated for these purposes by Mr Wilmer, under the title of the Coventry remedy. There it was sometimes employed merely in its pure state, combined with a sufficient quantity of honey, to form it into a bolus; sometimes it was given united with calcined cork and pumice-stone. What advantage, however, it could have derived from these additions it is difficult to conceive; nor can we readily see how it will be improved by the addition of common fea- falt here proposed: for this may probably lead to new combinations, materially altering the qualities of those salts which the sponge itself contains; and on which its virtues, as far as it has any, must depend. At the same time, for any experience which we ourselves have had, we are inclined to think, that those virtues which have been attributed to burnt sponge are more imaginary than real.

CHAP. XXVI. Troches.

Troches and lozenges are composed of powders made up with glutinous substances into little cakes, and afterwards dried. This form is principally used for the more commodious exhibition of certain medicines, by fitting them to dissolve slowly in the mouth, so as to pass by degrees into the stomach; and hence these preparations have generally a considerable proportion of sugar or other materials grateful to the palate. Some powders have likewise been reduced into troches, with a view to their preparation; though possibly for no very good reasons: for the moistening, and afterwards drying them in the air, must on this account be of greater injury than any advantage accruing from this form can counterbalance.

General Rules for making Troches.

1. The three first rules laid down for making powders, are also to be observed in the powders for troches.

2. If the mass proves so glutinous as to stick to the fingers in making up, the hands may be anointed with any convenient sweet or aromatic oil; or else sprinkled with powder of starch, or of liquorice, or with flour.

3. In order to thoroughly dry the troches, put them on an inverted sieve, in a shady airy place, and frequently turn them.

4. Troches are to be kept in glass vessels, or in earthen ones well glazed.

Troches of starch. L.

Take of starch, an ounce and an half; liquorice, six drams; florentine orris, half an ounce; double refined sugar, one pound and a half. Rub these to powder, and, by the help of tragacanth, dissolved in water, make troches. They may be made, if so chosen, without the orris.

White pectoral troches. E.

Take of purest sugar, one pound; gum arabic, four ounces; starch, one ounce; flowers of benzoin, half a dram. Having beat them all into a powder, make them into a proper mass with rose-water, so as to form troches.

These compositions are very agreeable pectorals, and may be used at pleasure. They are calculated for softening acrimonious humours, and allaying the tickling in the throat which provokes coughing.

Although not only the name but the composition Troches of liquorice. L.

Take of extract of liquorice, double-refined sugar, each ten ounces; tragacanth, powdered, three ounces. Make troches by adding water.

Black pectoral troches. E.

Take of extract of liquorice, gum arabic, each four ounces; white sugar, eight ounces. Dissolve them in warm water, and strain: then evaporate the mixture over a gentle fire till it be of a proper consistence for being formed into troches.

These compositions are designed for the same purposes as the white pectoral troches above described. In foreign pharmacopoeias there are some other troches of this kind, under the titles of Trochisci bechici flavii and rubri; the first are coloured with saffron, the latter with bole armenic. The dissolving and straining the extract of liquorice and gum arabic, as now ordered in the last of the above prescriptions, is a considerable improvement; not only as they are by that means more uniformly mixed than they can well be by beating, but likewise as they are thereby purified from the heterogeneous matters, of which both those drugs have commonly no small admixture.

Pectoral troches with opium. E.

Take of pure opium, two drams; balsam of Peru, one dram; tincture of Tolu, three drams. Grind the opium with the balsam and tincture previously mixed, till it be thoroughly dissolved; then add by degrees, of common syrup, eight ounces; extract of liquorice, softened in warm water, five ounces. While beating them diligently, gradually sprinkle upon the mixture five ounces of powdered gum arabic. Exsiccate so as to form troches, each weighing ten grains.

The directions for preparing the above troches are so full and particular, that no farther explanation is necessary. Six of the troches prepared in the manner here ordered, contain about one grain of opium. These troches are medicines of approved efficacy in tickling coughs depending on an irritation of the fauces. Besides the mechanical effect of the invigorating matters and involving acid humours, or lining and defending the tender membranes, the opium must, no doubt, have a considerable share, by more immediately diminishing the irritability of the parts themselves.

The composition of these troches, however, would perhaps be improved by the omission of the balsam of Peru: for although here directed only in small quantity, yet it gives a taste to the troches which is to many people very disagreeable; and it is at the same time probable that it adds very little, if any thing, to the efficacy of the medicine.

Troches of nitre.

Take of purified nitre powdered, four ounces; double-refined sugar, powdered, one pound; tragacanth, powdered, six ounces. With the addition of water, make troches.

Take of nitre, purified, three ounces; double-refined sugar, nine ounces. Make them into troches with mucilage of gum tragacanth.

This is a very agreeable form for the exhibition of nitre; though, when the salt is thus taken without any liquid (if the quantity be considerable), it is apt to occasion uneasiness about the stomach, which can only be prevented by large dilution with aqueous liquors. The troches of nitre have been said to be employed with success in some cases of difficult deglutition.

Troches of sulphur.

Take of washed flowers of sulphur, two ounces; double-refined sugar, four ounces. Rub them together; and, with the mucilage of quince-seeds, now and then added, make troches.

Take of flowers of sulphur, two ounces; flowers of benzoin, one scruple; white sugar, four ounces; factitious cinnabar, half a dram. Beat them together, and add mucilage of gum tragacanth as much as is sufficient. Mix and make them into troches according to art.

These compositions are to be considered only as agreeable forms for the exhibition of sulphur, no alteration or addition being here made to its virtues; unless that, by the flowers of benzoin in the second precipitation, the medicine is supposed to be rendered more efficacious as a pectoral.

The factitious cinnabar seems chiefly intended as a colouring ingredient.

Troches of chalk. L.

Take of chalk, prepared, four ounces; crabs-claws, prepared, two ounces; cinnamon, half an ounce; double-refined sugar, three ounces. These being rubbed to powder, add mucilage of gum arabic, and make troches.

Troches of magnesia. L.

Take of burnt magnesia, four ounces; double-refined sugar, two ounces; ginger, powdered, one scruple. With the addition of mucilage of gum arabic make troches.

These compositions are calculated against that uneasy sensation at the stomach, improperly called the heartburn; in which they often give immediate relief, by absorbing and neutralizing the acid juices that occasion this disorder. The absorbent powders here used are of the most powerful kind. The former has in general the effect of binding, the latter of opening, the belly; and from this circumstance the practitioner will be determined in his choice, according to the nature of the case which he may have occasion to treat.

Red lead troches. Dan.

Take of red lead, half an ounce; corrosive sublimate mercury, one ounce; crumb of the finest bread four ounces. Make them up with rose-water into oblong troches. These troches are employed only for external purposes as elcarotics: they are powerfully such, and require a good deal of caution in their use.

Troches of catechu. Brun.

Take of catechu, one ounce; white sugarcandy, two ounces; ambergris, musk, each ten grains; mucilage of gum tragacanth, as much as is sufficient. Make them into troches.

This medicine has long been in esteem as a slight restringent; and restringents thus gradually received into the stomach produce better effects than when an equal quantity is taken down at once. These troches would be more palatable, and perhaps not less serviceable, were the musk and ambergris omitted.

Chap. XXVII. Pills.

To this form are peculiarly adapted those drugs which operate in a small dose, and whose nauseous and offensive taste or smell require them to be concealed from the palate.

Pills dissolve the most difficulty in the stomach, and produce the most gradual and lasting effects of all the internal forms. This is in some cases of great advantage, in others it is a quality not at all desirable; and sometimes may even be of dangerous consequence, particularly with regard to emetics; which, if they pass the stomach undissolved, and afterwards exert themselves in the intestines, operate there as violent cathartics. Hence emetics are among us scarcely ever given in pills; and hence to the resinous and difficultly soluble substances, saponaceous ones ought to be added, in order to promote their solution.

Gummy resins, and inspissated juices, are sometimes soft enough to be made into pills without addition: where any moisture is requisite, spirit of wine is more proper than syrups or conserves, as it unites more readily with them, and does not sensibly increase their bulk. Light dry powders require syrup or mucilages; and the more ponderous, as the mercurial and other metallic preparations, thick honey, conserve or extracts.

Light powders require about half their weight of syrup, of honey, about three-fourths their weight, to reduce them into a due consistence for forming pills. Half a dram of the mass will make six or seven pills of a moderate size.

General Rules for making pills.

1. Gums and inspissated juices are to be first softened with the liquid preferred; then add the powders, and continue beating them all together till they be perfectly mixed.

2. The masses for pills are best kept in bladders, which should be moistened now and then with some of the same kind of liquid that the mass was made up with, or with some proper aromatic oil.

Ethiopic pills. E.

Take of quicksilver, six drams; golden sulphur of antimony, resin of guaiacum, honey, each half an ounce. Grind the quicksilver with the honey, in a glass mortar, until the mercurial globules entirely disappear; then add the golden sulphur and guaiacum, with as much mucilage of gum arabic as is sufficient to make the mixture into a mass of the proper consistence for forming pills.

These pills are much more efficacious than those of a former edition; the ethiops mineral, there ordered, being exchanged for a more active composition. In their present form, they resemble Dr Plummer's pills, described in the Edinburgh Essays, and afterwards to be mentioned. To it they are preferable in one respect, that they are less apt to run off by stool. They are an useful alternative both in cutaneous and venereal disorders. One fourth part of the quantity above preferrable may be made into sixty pills; of which from one to four may be taken every night and morning, the patient keeping moderately warm during the whole time that this course is continued.

Pills of aloes. L.

Take of socotrine aloes, powdered, one ounce; extract of gentian, half an ounce; syrup of ginger, as much as is sufficient. Beat them together.

Aloetic pills. E.

Take of socotrine aloes, in powder, thick extract of gentian, each two ounces; make them into a mass with simple syrup.

These pills were formerly directed to be made with Cattle soap; from a notion which Boerhaave and some others were very fond of, that soap promoted the solution of resinous and several other substances in the stomach. This, however, seems to be a mistake; and, on the contrary, it is highly probable that the alkaline part of the soap is in most instances separated from the oily by the acid in the stomach; by which decomposition the soap may possibly retard instead of promoting the solution of the aloes. These pills have been much used as warming and stomachic laxatives: they are very well suited for the cottiveness so often attendant on people of sedentary lives. Like other preparations of aloes, they are also used in jaundice, and in certain cases of obstructed menes. They are seldom used for producing full purging; but if this be required, a scruple or half a dram of the mass may be made into pills of a moderate size for one dose.

Pills of aloes with myrrh. L.

Take of socotrine aloes, two ounces; myrrh, saffron, of each one ounce; syrup of saffron, as much as is sufficient. Rub the aloes and myrrh separately to powder; afterwards beat them all together.

The common pills, vulgarly called Rufus's pills. E.

Take of socotrine aloes, two ounces; myrrh, one ounce; saffron, half an ounce. Beat them into a mass with a proper quantity of syrup.

These pills have long continued in practice, without any other alteration than in the syrup with which the mass is made up, and in the proportion of saffron. In our last pharmacopoeia, the syrup of wormwood was ordered, which is here judiciously exchanged by the London college for that of saffron; this preserving and improving the brightness of colour in the medicine, which is the characteristic of its goodness. The saffron, in the composition which is attributed to Rufus, is equal in quantity to the myrrh; and in these proportions the pill was received in our first pharmacopoeia. As the diminution afterwards made in the saffron was grounded on very absurd reasons, (viz. "left the former quantity should occasion a spasmodic cynicus,") the London college have now again increased it, and restored the pill to its original form. The virtues of this medicine may be easily understood from its ingredients. These pills, given to the quantity of half a dram or two scruples, prove considerably cathartic, but they answer much better purposes in smaller doses as laxatives or alteratives.

**Colocynth pills with aloes, commonly called Coccie. E.**

Take colocynthis aloes, scammony, of each two ounces; sal polychrest, two drams; colocynthis, one ounce; oil of cloves, two drams. Reduce the aloes and scammony into a powder with the salt; then let the colocynthis, beat into a very fine powder, and the oil be added; lastly, make it into a proper mass with mucilage of gum arabic.

In these pills we have a very useful and active purgative; and where the simple aloetic pill is not sufficient for obviating costiveness, this will often effectually answer the purpose. Little of their activity can depend upon the salt which enters the composition; but it may assist in dividing the active parts of the other articles, particularly the aloes and scammony. These pills often produce a copious discharge in cases of obstinate costiveness, when taken to the extent only of five or ten grains; but they may be employed in much larger doses. They are, however, seldom used with the view of producing proper catharsis. Half a dram of the mass contains about five grains of the colocynthis, ten of the aloes, and ten of the scammony.

**Copper pills. E.**

Take of cuprum ammoniacum, fifteen grains; crumb of bread, four scruples; spirit of sal ammoniac, as much as is sufficient to form them into a mass, which is to be divided into thirty-two equal pills.

These pills had formerly the name of Pilulae ceruleae, but they are now with greater propriety denominated from the metal which is their basis.

Each of these pills weighs about three grains, and contain somewhat more than half a grain of the cuprum ammoniacum. The above pills seem to be the best form of exhibiting this medicine. See Cuprum Ammoniacale, and Chemistry, No 1034.

**Gum pills.**

Take of galbanum, opopanax, myrrh, sagapenum, each one ounce; asafoetida, half an ounce; syrup of saffron, as much as is sufficient. Beat them together. L.

Take of asafoetida, galbanum, myrrh, each one ounce; rectified oil of amber, one dram. Beat them into a mass with simple syrup. E.

These pills are designed for antihysterics and emmenagogues, and are very well calculated for answering those intentions; half a scruple, a scruple, or more, may be taken every night or oftener. The fetid pills of our former pharmacopoeia were considerably purgative: the purgative ingredients are now omitted, as the physician may easily, in extemporaneous prescription, compound these pills with cathartic medicines, in such proportions as particular cases shall require.

**Quicksilver pills. L.**

Take purified quicksilver, extract of liquorice, having the consistence of honey, of each two drams; liquorice, finely powdered, one dram. Rub the quicksilver with the extract of liquorice until the globules disappear; then, adding the liquorice-powder, mix them together.

**Mercurial pills. E.**

Take of quicksilver, honey, each one ounce; crumbs of bread, two ounces. Grind the quicksilver with the honey in a glass mortar till the globules disappear, adding occasionally a little simple syrup; then add the crumbs of bread, and heat the whole with water into a mass, which is to be immediately divided into four hundred and eighty equal pills.

The quicksilver was formerly directed to be ground with resin of guaiacum and Calitile soap. The former was supposed to coincide with the virtues of the mercury, and the latter was used chiefly to divide the globules of mercury. For this last intention Dr Saunders found that honey, the substance here ordered by the Edinburgh college, is of all he tried the most effectual; but we would suppose with this gentleman, that something farther is done in this process than the mere division of the mercurial globules, and that part of the quicksilver is as it were amalgamated with the honey, or brought to a state similar to that in Plenck's solution. The same effect will take place when the pills are prepared with extract of liquorice now directed by the London college.

The mercurial pill is one of the best preparations of mercury, and may in general supersede most other forms of this medicine. It is necessary to form the mass immediately into pills, as the crumb soon becomes too hard for that purpose. Soap was undoubtedly a very improper medium for triturating the mercury; it is not only too hard for that purpose, but when the preparation entered the stomach, the alkaline part of the soap being engaged by the acid in that viscus, the mercury would in all probability be immediately separated. The honey and bread can only be changed by the natural powers of digestion, and can never oppress the stomach. The dose of the pills is from two to four or six in the day, according to the effects we wish to produce.

**Jalap pills. E.**

Take of extract of jalap, two ounces; aromatic powder, half an ounce. Beat them into a mass with simple syrup.

This is an useful and active purgative, either for evacuating the contents of the intestinal canal, or producing a discharge from the system in general. One of the same kind, with powdered jalap in substance instead of the extract, is used in some of our hospitals, as a cheap and effectual purge.

Plummer's pill. E.

Take of sweet mercury, precipitated sulphur of antimony, each six drams; extract of gentian, white Spanish soap, each two drams. Let the mercury be triturated with the sulphur till they be thoroughly mixed, then add the extract, and form a mass with simple syrup.

These pills were recommended to the attention of the public about forty years ago by Dr Plummer, whose name they still bear. He represented them in a paper which he published in the Edinburgh Medical Essays, as a very useful alternative; and on his authority they were at one time much employed; but they are now less extensively used than formerly. And although they still retain a place in the Edinburgh pharmacopoeia, yet it is probable that every purpose to be answered by them may be more effectually obtained from the common mercurial pill, or from calomel in a more simple state.

Opium pills. L.

Take of hard purified opium, powdered, two drams; extract of liquorice, one ounce. Beat them until they are perfectly united.

Thebaic, commonly called Pacific pills. E.

Take of opium, half an ounce; extract of liquorice, two ounces; Calile soap, an ounce and a half; Jamaica pepper, one ounce. Soften the opium and extract separately with proof-spirit, and having beat them into a pulp, mix them; then add the soap, and the pepper beat into a powder; and lastly, having beat them well together, form the whole into a mass.

These two compositions, though differing in several particulars, may yet be considered as fundamentally very much the same. The first is a simple opiate, in which every five grains of the mass contains one of opium; and in the opium alone can we suppose that the activity of the medicine depends.

Although some of the articles contained in the latter composition may perhaps be supposed to operate as corrigentia, yet the former composition, which is the most simple, is in general preferable.

Pills similar to the second were contrived by a chemical empiric, Starkey, and communicated by him to Matthews, under whose name they were some time ago greatly celebrated. The form here given differs considerably from the original, in omitting many ingredients of no great service. Nor indeed are any of the ingredients of much consequence, except the opium; their quantity being too inconsiderable to answer any useful purpose. Ten grains of the composition contain one of opium.

Squill-pills.

Take of fresh dried squills, powdered, one dram; ginger powdered, soap, of each three drams; ammoniacum, two drams; syrup of ginger, as much as is sufficient. Beat them together. L.

Take of gum ammoniac, lesser cardamom seeds, in powder, extract of liquorice, each one dram; dried root of squills, in fine powder, one scruple. Mix, and form them into a mass with simple syrup. E.

There are elegant and commodious forms for the exhibition of squills, whether for promoting expectoration, or with the other intentions to which that medicine is applied. As the virtue of the compound is chiefly from the squills, the other ingredients are often varied in extemporaneous prescription; and probably no material difference takes place in the two forms here proposed excepting in the proportion of the squills, which in the former constitutes one ninth, in the latter one tenth, of the mass.

Stomachic pills. E.

Take of rhubarb, one ounce; socotrine aloes, six drams; myrrh, half an ounce; vitriolated tartar, one dram; essential oil of mint, half a dram; syrup of orange peel, a sufficient quantity. Make them into a mass.

This pill is intended for moderately warming and strengthening the stomach, and evacuating crude viscid humours. A scruple of the mass may be taken twice a-day.

Bacher's pill. Gen.

Take of extract of black hellebore, purified myrrh, each one ounce; powder of carduus benedictus, two scruples. Mix them into a mass according to art, to be dried in the air till it be fit for the formation of pills, each weighing one grain.

These pills have been strongly recommended as a most effectual remedy in dropsical cases, and have been alleged to unite an evacuant and tonic power. Hence they have been considered as particularly suited to those cases where remarkable weakness and laxity occur. Under the hands of Mr Bacher the inventor, they acquired so great reputation, that, after a trial in the military hospitals at Paris, the receipt was purchased by the French king, and published by authority. But like many other nostrums since this publication, Bacher's pill has by no means supported the reputation which it had when kept a secret. The dose is varied according to circumstances, from one to thirty pills taken in the course of the day.

Pills of elaterium. Succ.

Take of the purest gum ammoniac, two ounces; socotrine aloes, gamboge, each two drams; elaterium, half a dram. Mix them, by means of bitter tincture, into a mass, and let pills be formed, each weighing two grains.

This, as well as the former, is also a pill celebrated for the cure of dropsical affections. And the elaterium, from which it derives its name, is one of the most powerful evacuants in the way of catharsis. Here, however, it is united with such active articles, particularly the gamboge, as must make its effect somewhat doubtful. And we are inclined to think that a preferable formula for making the pills of elaterium, is to form it into a mass, with the extract of gentian. This is imagined to have some influence as correcting its effect, in exciting sickness. And when each pill is made to contain half a grain of the elaterium, the dose may be easily accommodated to the circumstances of the patient, one or two pills being taken every hour till they begin to operate.

The elaterium, whether under the form above-mentioned, or in the more simple state which has now been suggested, operates as a very powerful cathartic, often inducing the discharge of stagnant serum, when other remedies are found ineffectual. But it can be exhibited only in those cases where the patient still retains a considerable degree of strength.

**Fetid pills. Suec.**

Take of asafoetida, castor, each a dram and a half; salt of amber, half a dram; oil of hartshorn, half a scruple. Make them into a mass, with tincture of myrrh, to be divided into pills of two grains each.

These, like the gum-pills formerly mentioned, are chiefly used as an antihysteric and antispasmodic medicine; and they are particularly useful in counteracting spasmodic affections of the alimentary canal, especially those connected with flatulence. But the asafoetida is no less successful when exhibited in a more simple state, particularly when formed into pills with an equal quantity of soap, by the aid of simple syrup.

**Gamboge pills. Dan.**

Take of socotrine aloes, extract of black hellebore, sweet mercury, gamboge, each two drams; distilled oil of juniper, half a dram; syrup of buckthorn, as much as is sufficient for forming a mass of pills.

From the ingredients of which these pills are constituted, we need hardly remark, that they must prove a very powerful purgative. The gamboge, from which they derive their name is unquestionably a very active purge. But it is not more so than the sweet mercury; and perhaps from an union of these two, as much might be expected as from the more compounded formula here adopted. Yet it is not improbable that the essential oil of juniper may in some degree operate as a corrigent.

**Pills of corrosive sublimate mercury. Suec.**

Take of corrosive sublimate, purified sal ammoniac, each one scruple; distilled water, as much as is sufficient to dissolve them; powder of the root of althea, fifteen scruples; honey, two drams. Mix them into a mass for the formation of pills, each weighing three grains.

Corrosive sublimate in substance was long considered as being so violent in its effects, that it could not with safety be taken internally; but for a considerable time it has been used with advantage under the form of solution, either in water or spirits. But to both these a considerable objection occurs from their disagreeable brassy taste. This objection is however entirely obviated, by reducing the solution, after it is formed, to a solid mass, by means of crumb of bread, or any proper powder; and by the aid of a little sal ammoniac, the solution may be made in a very small quantity of water; so that less of any solid intermediate will be sufficient to bring it to the form of preparations. The formula here directed seems well suited for the purpose intended. Each of the pills contains about an eighth of a grain of the corrosive; thus the dose may be easily regulated according to the intention in view. And these pills are not unfrequently employed with advantage, both in combating venereal and cutaneous affections, and for the expulsion of worms from the alimentary canal. With the latter of these intentions, a similar pill was particularly recommended by Dr Gardner, in a paper published in the Edinburgh Physical and Literary Essays; and although not received into our pharmacopoeia, it has been frequently used at Edinburgh.

**Tar-pills. Dan.**

Take any quantity of tar, and mix with it as much powdered elecampane root as will reduce it to a proper thickness for being formed into pills.

The powder here mixed with the tar, though of no great virtue, is nevertheless a very useful addition, not only for procuring it a due consistence, but likewise as it divides the resinous texture of the tar, and thus contributes to promote its solution by the animal juices. In the Edinburgh infirmary, half a dram of the mass, made into middle-sized pills, is given every morning and evening in disorders of the breast, scurvy, &c.

**Soap-pills. Suec.**

Take of hard white soap, two ounces; extract of birch, one ounce. Let them be formed into a mass, to be divided into pills, each containing three grains.

Although many virtues have been attributed to the birch, yet we are inclined to think, that it here serves little other purpose than to give the form of pills to the soap. And this article, even when taken in small quantity with some constitutions, operates as a gentle laxative. But besides this, it has also been supposed to be highly useful both in cases of jaundice and of calculus. There can, however, be little doubt, that the theories on which it has been inferred that it may be useful in such complaints are not well founded; and we may perhaps add, that the use of it, even to a great extent, is by no means attended with those consequences which were once alleged to arise from it.

**Storax-pills. Suec.**

Take of strained storax, five scruples; extract of liquorice, three drams; opium, one dram. Let the opium, dissolved in wine, be added to the other ingredients, so as to form a mass of proper consistence, to be made into pills, each weighing three grains.

These pills are principally active in consequence of the opium which they contain. And they are chiefly meant with a view to a slow solution in the stomach, and consequently producing more gradual and lasting effects. One grain of opium is contained in seventeen grains of the mass.

**Chap. XXVIII. Electuaries.**

Electuaries are composed chiefly of powders mixed up with syrups, &c., into such a consistence that the powders may not separate in keeping, that a dose may be easily taken upon the point of a knife, and not prove too stiff to swallow.

Electuaries receive chiefly the milder alternative medicines, and such as are not ungrateful to the palate. The more powerful drugs, as cathartics, emetics, opiates, and the like (except in officinal electuaries to be dispensed by weight), are seldom trusted in this form, on account of the uncertainty of the dose; difficult ones, acrids, bitters, fetids, cannot be conveniently taken in it; nor is the form of an electuary well fitted for the more ponderous substances, as mercurials, these being apt to subside in keeping, unless the composition be made very stiff.

The lighter powders require thrice their weight of honey, or syrup boiled to the thickness of honey, to make them into the consistence of an electuary; of syrups of the common consistence, twice the weight of the powder is sufficient.

Where the common syrups are employed, it is necessary to add likewise a little conserve, to prevent the compound from drying too soon; electuaries of Peruvian bark, for instance, made up with syrup alone, will often in a day or two grow too dry for taking.

Some powders, especially those of the less grateful kind, are more conveniently made up with mucilage than with syrup, honey, or conserve. The three latter stick about the mouth and fauces, and thus occasion the taste of the medicine to remain for a considerable time; while mucilages pass freely, without leaving any taste in the mouth. A little soft extract of liquorice, joined to the mucilage, renders the composition sufficiently grateful, without the inconveniences of the more adhesive sweets.

The quantity of an electuary, directed at a time, in extemporaneous prescription, varies much according to its constituent parts, but it is rarely less than the size of a nutmeg, or more than two or three ounces.

General rules for making electuaries.

I. The rules already laid down for decoctions and powders in general, are likewise to be observed in making decoctions and powders for electuaries.

II. Gums, inspissated juices, and such other substances as are not pulverizable, should be dissolved in the liquor prescribed; then add the powders by little and little, and keep the whole briskly stirring, so as to make an equable and uniform mixture.

III. Astringent electuaries, and such as have pulps of fruit in their composition, should be prepared only in small quantities at a time; for astringent medicines lose much of their virtue on being kept in this form, and the pulps of fruits are apt to become sour.

IV. The superfluous moisture of the pulps should be exhaled over a gentle fire, before the other ingredients are added to them.

V. Electuaries, if they grow dry in keeping, are to be reduced to a due consistence, with the addition of a little Canary wine, and not with syrup or honey: by this means the dose will be the least uncertain; a circumstance deserving particular regard, in those especially which are made up with syrup, and contain a proportion of opium.

Elecuary of cassia. L.

Take of the fresh extracted pulp of cassia, half a pound; manna, two ounces; pulp of tamarinds, one ounce; rose-syrup, half a pound. Beat the manna, and dissolve it over a slow fire in the rose-syrup; then add the pulps; and with a continued heat evaporate the whole to the proper thickness of an electuary.

Elecuary of cassia, commonly called diacacia. E.

Take of pulp of cassia fistularis, six ounces; pulp of tamarinds, manna, each an ounce and a half; syrup of pale roses, six ounces. Having beat the manna in a mortar, dissolve it with a gentle heat in the syrup; then add the pulps, and evaporate them with a regularly continued heat to the consistence of an electuary.

These compositions are very convenient officinals, to serve as a basis for purgative electuaries and other similar purposes; as the pulping a small quantity of the fruits, for extemporaneous prescription, is very troublesome. The tamarinds give them a pleasant taste, and do not subject them, as might be expected, to turn sour. After standing for four months, the composition has been found no fouler than when first made. This electuary likewise is usefully taken by itself, to the quantity of two or three drams occasionally, for gently loosening the belly in colicive habits.

Elecuary of scammony. L.

Take of scammony, in powder, one ounce and an half; cloves, ginger, of each six drams; essential oil of caraway, half a dram; syrup of roses, as much as is sufficient. Mix the spices, powdered together, with the syrup; then add the scammony, and lastly the oil of caraway.

This electuary is a warm brisk purgative. It is a reform of the elecuarium caryocatinum of our preceding dispensatories; a composition which was greatly complained of, as being inconvenient to take on account of the largeness of its dose. A dram and a half of this, which contains fifteen grains of scammony, is equivalent to half an ounce of the other.

Elecuary of senna. L.

Take of senna, eight ounces; figs, one pound; pulp of tamarinds, of cassia, of prunes, each half a pound; coriander seeds, four ounces; liquorice, three ounces; double-refined sugar, two pounds and an half. Powder the senna with the coriander seeds, and sift out ten ounces of the mixed powder. Boil the remainder with the figs and liquorice, in four pints of distilled water, to one half; then press out and strain the liquor. Evaporate this strained liquor to the weight of about a pound and an half; then add the sugar, and make a syrup; add this syrup by degrees to the pulps, and lastly mix in the powder.

Lenitive elecuary. E.

Take of pulp of French prunes, one pound; pulp of cassia, pulp of tamarinds, each two ounces and a half; black syrup of sugar, commonly called molasses, one pound and a half; fenna leaves, in fine powder, four four ounces; coriander seeds, in fine powder, half an ounce. Having boiled the pulps with the syrup to the consistence of honey, add the powders, and beat the whole into an electuary.

This electuary, the name of which is with propriety changed by the London college, is now freed from some superfluous ingredients which were left in it at former revivals, viz. polyody root, French mercury leaves, fenugreek seeds, and linseed. Molasses is preferable to either honey or sugar, as it coincides with the intention, and is not only of itself inapt to ferment, but likewise prevents such substances as are this way disposed from running into fermentation.

It is a very convenient laxative, and has long been in common use among practitioners. Taken to the quantity of a nutmeg or more, as occasion may require, it is an excellent laxative for loosening the belly in costive habits.

Japonic electuary, commonly called Japonic confection. E.

Take of Japan earth, four ounces; gum-kino, three ounces; cinnamon, nutmeg, each one ounce; opium diffused in a sufficient quantity of Spanish white wine, one dram and a half; syrup of dried roses, boiled to the consistence of honey, two pounds and a quarter. Mix and form them into an electuary.

The ingredients in this electuary seem extremely well chosen, and are so proportioned to one another, that the quantity of opium is the same as in the diacordium of the former pharmacopoeias of Edinburgh, viz. one grain in ten scruples. The gum-kino, now substituted for the tormentil root, is an excellent improvement in the formula.

Tin electuary. Brun.

Take of pure tin, quicksilver, each one ounce. Let them be formed into an amalgam; oyster-shells, prepared, one ounce. Reduce the whole to a powder. Take of this powder, conserve of wormwood, each one ounce, and form an electuary with syrup of mint.

Tin, as we have already had occasion to observe above (no 312.), has long been celebrated for the expulsion of tenia; and it is also well known, that in mercury we have one of the most powerful anthelmintics. Such a combination as the present, then, might be supposed well suited for the removal of that animal from the alimentary canal; and accordingly it has been alleged, that this electuary has sometimes succeeded after other remedies have failed. It may be taken twice a-day, to the extent of two or three drams for a dose.

Electuary for the gums. Suec.

Take of powdered myrrh, three drams; cream of tartar, cochineal, each a dram and a half. Grind them together in a glass mortar; then add melted honey, four ounces; cloves, in powder, one dram.

Myrrh, particularly under the form of tincture, has long been a favourite application to the gums, when in a spongy or ulcerated state. But the spirituous menstruum there employed, although sometimes favouring the intention in view, in other instances occurs as an objection to its use. In these cases, the benefit to be derived from the myrrh may be obtained from this Preparatory, which may always be applied with safety, and sometimes with advantage.

Electuary of manna. Suec.

Take of manna, refined sugar pounded, fennel-water, each two ounces. Strain the mixture, using expression; then add fine powder of the root of florentine orris, one dram; fresh drawn almond oil, one ounce.

In this electuary we have a gently emollient laxative, which is very useful in those cases where obstipation either arises from indurated feces, or is supported by that cause. But its cathartic powers are by no means considerable.

Nitrous electuary. Gen.

Take of purified nitre, half an ounce; conserve of roses, four ounces. Mix them.

Under this formula nitre may be introduced to a considerable extent, without giving uneasiness at stomach, while at the same time its refrigerant power is combined with the astringency of the roses. From these circumstances it may be advantageously employed in different cases, but particularly in instances of hæmoptysis.

Terpenininate electuary. Suec.

Take of spirit of turpentine, half an ounce; honey, one ounce; powder of liquorice, as much as is sufficient for the formation of an electuary.

Under this form, the oil of turpentine may be introduced with less uneasiness than perhaps under almost any other. And it may thus be employed for different purposes, but particularly with a view to its diuretic power. But it has been especially celebrated for the cure of obstinate rheumatisms, and above all, for that modification of rheumatism which has the name of iofibria, and which is found in many instances obstinately to resist other modes of cure.

Lenient linæus. Suec.

Take of gum-arabic, bruised, two drams; cherry-water, half an ounce. By trituration in a mortar, mix with them almond oil, fresh drawn, syrup of almonds, each seven ounces.

In this we have a very agreeable emollient linæus, highly useful in recent catarrhal affections, for lubricating the throat and fauces. It may be taken at pleasure to any extent that the stomach may easily bear.

CHAP. XXIX. Confections.

Although the London college have separated these from electuaries, yet they differ so little, that in most pharmacopoeias they are ranked under the same head. And in that of Edinburgh, there are several articles which have promiscuously the name either of confection or electuary. But as no inconvenience arises from the separation, and as we have followed the order of the London pharmacopoeia in other particulars, it would be improper to deviate from it in this. Aromatic confection. L.

Take of zedoary, in coarse powder, saffron, of each half a pound; distilled water, three pints. Macerate for twenty-four hours; then press and strain. Reduce the strained liquor, by evaporation, to a pint and a half, to which add the following, rubbed to a very fine powder; compound-powder of crab-claws, fifteen ounces; cinnamon, nutmegs, of each two ounces; cloves, one ounce; smaller cardamom-seeds, husked, half an ounce; double-refined sugar, two pounds. Make a confection.

This confection is composed of the more unexceptionable ingredients of a composition formerly held in great esteem, and which was called, from its author, confection Raleighana. The original confection was composed of no less than five and twenty particulars; each of which were examined apart, except one, moorgals, the flower of which is too small to be gathered in sufficient quantity for the general use of the medicine, and the plant is possessed of hurtful qualities, as is experienced in cattle that feed where it grows. In this examination, many of the extracts came out so very nauseous, that it was impossible to retain them, consistent with any regard to the taste of the composition. But some few, of equal efficacy with any of the rest, being of a tolerable taste and flavour, were compounded in different proportions; and when, after many trials, a composition was approved, the quantity of each material, that would yield the proportion of extract which entered that composition, was calculated, and from thence the proportions were collected as now set down: after which the compound extract was made, and found to answer expectation. The London college, in the present edition of their pharmacopoeia, have still farther simplified this formula, by rejecting the rosemary, juniper, and cardamoms, which formerly entered it.

The confection, as now reformed, is a sufficiently grateful and moderately warm cordial; and frequently given with that intention, from eight or ten grains to a scruple or upwards, in boluses or draughts. The formula might perhaps be still more simplified without any loss. The crab-claw powder does not appear to be very necessary, and is inserted rather in compliance with the original formula, than from its contributing anything to the intention of the medicine; and the following formula of the Edinburgh pharmacopoeia seems to us preferable to that of the London, even in its present improved state.

Cordial electuary, commonly called cordial confection. E.

Take of conserve of orange-peel, three ounces; preserved nutmegs, an ounce and a half; preserved ginger, six drams; cinnamon, in fine powder, half an ounce; syrup of orange peel, as much as will form the whole into an electuary.

In the above simple and elegant formula, a number of trifling ingredients are rejected, and those substituted in their place are medicines of approved efficacy. We therefore consider this preparation as a useful remedy for the purposes expressed in its title.

Confection of opium. L.

Take of hard purified opium, powdered, six drams; long pepper, ginger, caraway seeds, of each two ounces; syrup of white poppy, boiled to the consistence of honey, three times the weight of the whole. Mix the purified opium carefully with syrup gently heated; then add the rest, rubbed to powder.

Thebaic electuary. E.

Take of aromatic powder, six ounces; Virginian snakeroot, in fine powder, three ounces; opium diffused in a sufficient quantity of Spanish white wine, three drams; clarified honey, thrice the weight of the powders. Mix them, and form an electuary.

These compositions consist of very powerful ingredients, and are doubtless capable of answering every end that can be reasonably expected from the more voluminous Theriaca of Andromachus. The London college also had formerly their Theriaca composed of the less exceptionable ingredients of Andromachus's. But as these medicines have for a long time been chiefly employed for external purposes, by the way of cataplasm, the London theriaca is now omitted, and its place supplied by a cataplasm composed of a few well-chosen articles, under the name of cataplasm of cummin; of which hereafter. For internal use, none of the theriacas are at present so much regarded as they have been heretofore; practitioners having introduced in their room contemporaneous boluses of Virginian snakeroot, camphor, contrayerva, and the like; which answer all their intentions, with this advantage, that they may be given either with or without opium; an ingredient which renders the others prejudicial in cases where they might otherwise be proper.

With regard to the quantity of opium in the foregoing compositions, one grain thereof is contained in thirty-six grains of the confection of opium, and in five scruples of the thebaic electuary. The proportion of opium will vary a little, according to the time that they have been kept; their moisture by degrees exhaling, so as to leave the remainder stronger of the opium than an equal weight was at first. A change of this kind is taken notice of by many writers, but falsely attributed to an imaginary fermentative quality of the ingredients; by which they were supposed, from their multiplicity and contrariety, to be continually exalting and improving the virtues of each other.

A good deal of care is requisite in making these compositions, to prevent the waste which is apt to happen in the pounding, and which would render the proportion of opium to the other ingredients precarious. The intention of dissolving the opium in wine, for these and other electuaries, is, that it may be more uniformly mixed with the rest.

These compositions fully supply the place of two articles, which, though long banished from the shops, we shall here subjoin, as examples of the amazing height to which composition in medicine had at one time proceeded.

Mithridate, or the confection of Democrates.

Take of cinnamon, fourteen drams; myrrh, eleven drams; agaric, Indian nard, ginger, saffron, seeds of mithridate mustard, frankincense, chio turpentine, each ten drams; camel's hay, costus, or in its stead zedoary, India leaf, or in its stead mace, stachas long... long pepper, hartwort seeds, hypociftis, storax strained, opoponax, galbanum strained, opobalsam, or in its stead expressed oil of nutmegs, Russian caftor, each one ounce; Poley mountain, scordium, carpopallam, or in its stead cubebes, white pepper, candy-carrot seed, bdellium strained, each seven drams; Celtic nard, gentian root, dittany of Crete, red roses, Macedonian parsley seed, lesser cardamom seeds husked, sweet fennel seed, gum arabic, opium strained, each five drams; calamus aromaticus, wild valerian root, aniseed, lagapenum strained, each three drams; meum athamanticum, St John's wort, acacia, or in its stead terra Japonica, bellies of skinks, each two drams and a half; clarified honey, thrice the weight of all the other ingredients. Warm the honey, and mix with it the opium dissolved in wine; melt the storax, galbanum, turpentine, and opobalsam (or expressed oil of nutmegs), together in another vessel, continually stirring them about, to prevent their burning; with these so melted, mix the hot honey, at first by spoonfuls, and afterwards in larger quantities at a time; when the whole is grown almost cold, add by degrees the other spices reduced into powder.

**Theriaca of Andromachus, or Venice treacle.**

Take of traches of squills, half a pound; long pepper, opium strained, vipers dried, each three ounces; cinnamon, opobalsam, or in its stead expressed oil of nutmegs, each two ounces; agaric, Florence orris root, scordium, red roses, navet seeds, extract of liquorice, each an ounce and a half; Indian nard, saffron, amomum, myrrh, costus, or in its stead zedoary, camel's hay, each one ounce; cinquefoil root, rhubarb, ginger, Indian leaf, or in its stead mace, dittany of Crete, horehound leaves, calamin leaves, stechas, black pepper, Macedonian parsley seed, olibanum, chio turpentine, wild valerian root, each six drams; gentian root, Celtic nard, spigelia, leaves of Poley mountain, of St John's wort, and of groundpine, germander tops with the seed, carpopallam, or in its stead cubebes, aniseed, sweet fennel seed, lesser cardamom seeds, husked, seeds of bishop's weed, of hartwort, and of treacle mustard, hypociftis, acacia, or in its stead Japan earth, gum arabic, storax strained, lagapenum strained, terra Lemnia, or in its stead bole armeniac, or French bole, green vitriol calcined, each half an ounce; small (or in its stead the long) birthwort root, lesser centaury tops, candy-carrot seed, opopanax, galbanum, strained, Russia caftor, Jews pitch, or in its stead white amber prepared, calamus aromaticus, each two drams; clarified honey, thrice the weight of all the other ingredients. Let these ingredients be mixed together, after the same manner as directed in making the mithridate.

These celebrated electuaries are often mentioned by medical writers, and may serve as examples of the wild exuberance of composition which the superstition of former ages brought into vogue. The theriaca is a formation of mithridate made by Andromachus physician to Nero. The mithridate itself is said to have been found in the cabinet of Mithridates king of Pontus. The first publishers of this pompous arcanum were very extravagant in their commendations of its virtues; the principal of which was made to consist in preparing it being a most powerful preservative against all kinds of venom; whoever took a proper quantity in a morning was insured from being poisoned during that whole day. This was confirmed by the example of its supposed inventor, who, as Celsus informs us, was by his constant use so fortified against the commonly reputed poisons, that none of them would have any effect upon him when he wanted their assistance. But the notions of poisons which prevailed in those ruder ages were manifestly erroneous. Before experience had furnished mankind with a competent knowledge of the powers of simples, they were under perpetual alarms from an apprehension of poisons, and busied themselves in contriving compositions which should counteract their effects, accumulating together all those substances which they imagined to be possessors of any degree of alexipharmac power. Hence proceed the voluminous antidotes which we meet with in the writings of the ancient physicians; yet it does not appear that they were acquainted with any real poison except the cicuta, aconitum, and bites of venomous animals; and for these they knew of no antidote whatever. Even admitting the reality of the poisons, and the efficacy of the several antidotes separately, the compositions could no more answer the purposes expected from them, than the accumulating of all the medicinal simples into one form could make a remedy against all diseases.

Yet notwithstanding the absurdity in the original intention of these medicines, and their enormity in point of composition, as they contain several powerful materials, whose virtues, though greatly prejudiced, yet are not destroyed, by their multiplicity and contrariety; the compounds have been found, from repeated experience, to produce very considerable effects as warm opiate diaphoretics.

These compositions might without doubt be kept of numerous superfluities without any diminution of their virtues; yet as the effects of them, in their present form, are so well known, so much regard has been paid to ancient authority as not to attempt a reformation of that kind. Although these forms were originally complex, yet subsequent additions had crept into them. Neither the description in verse of the elder Andromachus, nor the prose explanation of the younger, make any mention of the white pepper afterwards added to the theriaca; and the orris root, in the mithridate of our former pharmacopoeias, is also a supernumerary ingredient, not warranted by the original: these therefore are rejected. Nor is the alum in the mithridate grounded on any good authority: the verse it is taken from is mutilated and corrupt; and the word which some, on conjecture only, suppose to have been afarum, others, also on conjecture, choose to read differently. Till some emendation shall be better founded than merely on critical guesses, this single species may be safely passed over without any prejudice to the medicine. None of the ancient descriptions afford any other light in this particular; for they either omit this ingredient, and others also, or abound with additions.

Another innovation on both these medicines also took place. In each of these compositions were found both cinnamon and cassia lignea; and it is very evident, from several parts of Galen's works, that the latter was used by the ancients only on account of the great difficulty of procuring the other; so that to retain the cassia, now that cinnamon is so common, is a blind following of these writers, without any attention to their meaning: the cassia therefore is now rejected, and half the quantity of cinnamon put in its room; which is the proportion that Galen directs to be observed in substituting the one for the other. It is probable that the case is the same with regard to the Celtic and the Indian nard; that the first had a place in these compositions on account of the difficulty of procuring the Indian, for Galen expressly prefers the latter.

There is a material error in regard to the theriaca, which has passed through several editions of our pharmacopoeia: this is the substituting the Roman vitriol for the ancient chalcitis, now not certainly known; and, in the catalogue of simples, describing the Roman to be a blue vitriol, whereas the Italian writers are unanimous it is a green vitriol; and were it not, it would not answer to the effects of the chalcitis, which was certainly a chalybeate, and gives the medicine its black colour. What has chiefly occasioned chalcitis to be supposed a cupreous vitriol seems to be its name, derived from καλκίς, copper; but it is to be observed that all vitriols were formerly imagined to proceed from copper, and were named accordingly; the green or martial vitriols are still called by the Germans kupfer-wasser, and by us copperas. It is probable that the ancient chalcitis was no other than a native martial vitriol, calcined by the heat of those warm climates to a degree of yellowish red or coppery colour; and therefore the common green vitriol, thus calcined by art, very properly supplies its place.

The preparation of these medicines has been somewhat facilitated by omitting the trochisci cypheos used in the mithridate, and the bedychroei and viperini for the theriaca; and inferring their ingredients, after Zwelfer's manner, in the compositions they are intended for. This is done in the theriaca very commodiously; the ingredients in these troches uniting with those in the theriaca itself into unbroken numbers. But to render the numbers equally simple in the mithridate, it was necessary to retrench a few odd grains from some of the articles, and make a small addition to some others. The proportions of the ingredients in the trochisci cypheos are adjusted from the original description in Galen, the numbers in our former pharmacopoeia being very erroneous.

Both the London and Edinburgh colleges ventured at length to discard these venerable relics. The Edinburgh college at first substituted in their room an elegant and simple form, equivalent to them both in efficacy, under the title of theriaca Edinensis, Edinburgh theriaca. In later editions, however, they have entirely banished the name of theriaca from their book, and have put in its place the more elegant composition already mentioned, the thebaic electuary.

**CHAP. XXX. Medicated Waters.**

We have already taken notice of many articles which are either dissolved in water, or communicate their virtues to it; and in one sense of the word these may be called medicated waters. Sometimes this impregnation is effected by the aid of heat, sometimes without it; and thus are formed decoctions, infusions, compositions, and the like. But among those articles referred to in this chapter, there takes place mere watery solution only, and they are used solely with the intention of acting topically in the way of lotion, injection, or at the utmost of gargarism.

**Compound alum water. L.**

Take of alum, vitriolated zinc, each half an ounce; boiling distilled water, two pints. Pour the water on the salts in a glass vessel, and strain.

This water was long known in our shops under the title of aqua aluminosa Batanae.

Bates directed the salts to be first powdered and melted over the fire; but this is needless trouble, since the melting only evaporates the aqueous parts, which are restored again on the addition of the water. This liquor is used for cleansing and healing ulcers and wounds; and for removing cutaneous eruptions, the part being bathed with it hot three or four times a day. It is sometimes likewise employed as a collyrium; and as an injection in the gonorrhoea and fluor albus, when not accompanied with virulence.

**Styptic water. E.**

Take of blue vitriol, alum, each three ounces; water, two pounds. Boil them until the salts be dissolved; then filter the liquor, and add an ounce and an half of vitriolic acid.

This water, though made with the blue in place of the white vitriol, cannot be considered as differing very much from the former. It is formed on the styptic recommended by Sydenham for stopping bleeding at the nose, and other external hemorrhages; for this purpose cloths or dressings are to be dipped in the liquor, and applied to the part.

**Water of ammoniated copper. L.**

Take of lime-water, one pint; sal ammoniac, one dram. Let them stand together, in a copper vessel, till the ammonia be saturated.

**Sapphire-coloured water. E.**

Take of lime-water, newly made, eight ounces; sal ammoniac, two scruples; verdigris, powdered, four grains. Mix them, and after 24 hours strain the liquor.

This is a much more elegant and convenient method than the preceding.

This water is at present pretty much in use as a detergent of foul and obstinate ulcers, and for taking away specks or films in the eyes. The copper contributes more to its colour than to its medicinal efficacy; for the quantity of the metal dissolved is extremely small.

**Compound water of acetated litharge. L.**

Take of acetated water of litharge, two drams; distilled water, two pints; proof-spirit, two drams. Mix the spirit with the acetated water of litharge; then add the distilled water. This liquor is of the same nature with solutions of sugar of lead, and is analogous to the vegeto-mineral water of Mr Goulard. It is only used externally as a cosmetic against cutaneous eruptions, redness, inflammation, &c. But even here it is alleged that it is not altogether void of danger, and that there are examples of its continued employment having occasioned sundry ill consequences. But at the same time the very frequent use that is made of it with perfect impunity would lead us to conclude that in these observations there must be some mistake.

Water of vitriolated zinc with camphor. L.

Take of vitriolated zinc, half an ounce; camphorated spirit, half an ounce; boiling water, two pints. Mix, and filter through paper.

This is an improved method of forming the vitriolic camphorated water of the former editions of the London pharmacopoeia. It is used externally as a lotion for some ulcers, particularly those in which it is necessary to restrain a great discharge. It is also not unfrequently employed as a collyrium in some cases of ophthalmia, where a large discharge of watery fluid takes place from the eyes, with but little inflammation. But when it is to be applied to this tender organ, it ought, at first at least, to be diluted by the addition of more water.

Vitriolic water. E.

Take of white vitriol, fifteen grains; water, eight ounces; weak vitriolic acid, fifteen drops. Dissolve the vitriol in the water, and then adding the acid, strain through paper.

Where the eyes are watery or inflamed, this solution of white vitriol is a very useful application. The slighter inflammations will frequently yield to this medicine without any other assistance; in the more violent ones, venefication and cathartics are to be premised to its use.

Chap. XXXI. Plasters.

Plasters are composed chiefly of oily and unctuous substances, united with powders into such a consistence that the compound may remain firm in the cold without sticking to the fingers; that it may be soft and pliable in a low degree of heat, and that by the warmth of the human body it be so tenacious as readily to adhere both to the part on which it is applied and to the substance on which it is spread.

There is, however, a difference in the consistence of plasters, according to the purposes they are to be applied to; thus, such as was intended for the breast and stomach should be very soft and yielding, while those designed for the limbs are made firmer and more adhesive. An ounce of expressed oil, an ounce of yellow wax, and half an ounce of any proper powder, will make a plaster of the first consistence; for a hard one, an ounce more of wax, and half an ounce more of powder, may be added. Plasters may likewise be made of resins, gummy resins, &c., without wax, especially in extemporaneous prescription: for officinals these compositions are less proper, as they soon grow too soft in keeping, and fall flat in a warm air.

It has been supposed, that plasters might be impregnated with the specific virtues of different vegetables, by boiling the recent vegetable with the oils employed for the composition of the plaster. The coction was continued till the herb was almost crisp, with care to prevent the matter from contracting a black colour: after which the liquid was strained off, and set on the fire again, till all the aqueous moisture had exhale. We have already observed, that this treatment does not communicate to the oils any very valuable qualities, even relative to their use in a fluid state: much less can plasters, made with such oils, receive any considerable efficacy from the herbs.

Calcei of lead, boiled with oils, unite with them into a plaster of an excellent consistence, and which makes a proper basis for several other plasters.

In the boiling of these compositions, a quantity of water must be added, to prevent the plaster from burning and growing black. Such water, as it may be necessary to add during the boiling, must be previously made hot; for cold liquor would not only prolong the process, but likewise occasion the matter to explode, and be thrown about with violence, to the great danger of the operator: this accident will equally happen on the addition of hot water, if the plaster be extremely hot.

Ammoniacum plaster with quicksilver. L.

Take of strained ammoniacum, one pound; purified quicksilver, three ounces; sulphurated oil, one dram, or what is sufficient. Rub the quicksilver with the sulphurated oil until the globules disappear; then add, by little at a time, the melted ammoniacum, and mix them.

This is a very well contrived mercurial plaster. The ammoniacum in general affords a good basis for the application of the mercury. In some cases, however, it is not sufficiently adhesive. But this inconvenience, when it does occur, may be readily remedied by the addition of a small quantity of turpentine.

Plaster of Spanish flies. L.

Take of Spanish flies, one pound; wax plaster, two pounds; prepared hog's lard, half a pound. Having melted the plaster and lard, a little before they coagulate sprinkle in the flies, reduced to a very fine powder.

Blistering plaster, or epispastic plaster. E.

Take of hog's lard, yellow wax, white resin, cantharides, each equal weights. Beat the cantharides into a fine powder, and add them to the other ingredients, previously melted, and removed from the fire. Both these formulas are very well suited to answer the intention in view, that of exciting blisters; for both are of a proper consistence, and sufficient degree of tenacity, which are here the only requisites. Cantharides of good quality, duly applied to the skin, never fail of producing blisters. When, therefore, the desired effect does not take place, it is to be ascribed to the flies either being faulty at first, or having their activity afterwards destroyed by some accidental circumstance; such as too great heat in forming, in spreading the plaster, or the like. And when due attention is paid to these particulars, the simple compositions now introduced answer the purpose better than those compound plasters with mustard-seed, black pepper, vinegar, verdigris, and the like, which had formerly a place in our pharmacopoeias. It is not however improbable, that the pain of blistering-plasters might be considerably diminished by the addition of a portion of opium, without preventing the good effects otherwise to be derived from them.

Wax-plaster.

Take of yellow wax, prepared mutton-fuet, each three pounds; yellow resin, one pound. Melt them together, and strain the mixture whilst it is fluid.

Take of yellow wax, three parts; mutton-fuet, white resin, two parts. Melt them together into a plaster; which supplies the place of melilot plaster.

This plaster had formerly the title of drawing plaster, and was chiefly employed as a dressing after blisters, to support some discharge.

It is a very well contrived plaster for that purpose. It is calculated to supply the place of melilot plaster; whose great irritation, when employed for the dressing of blisters, has been continually complained of. This was owing to the large quantity of resin it contained, which is here on that account retrenched. It would seem that, when designed only for dressing blisters, the resin ought to be entirely omitted, unless where a continuance of the pain and irritation, excited by the vesicatory, is required. Indeed plasters of any kind are not very proper for this purpose: their consistence makes them fit uneasily, and their adhesiveness renders the taking them off painful. Cerates, which are softer and less adhesive, appear much more eligible: the cerate of spermaceti will serve for general use; and for some particular purposes, the cerate of yellow resin may be applied.

Cummin-plaster. L.

Take of the seeds of cummin, seeds of caraway, bayberries, each three ounces; Burgundy-pitch, three pounds; yellow wax, three ounces. Mix, with the melted pitch and wax, the rest of the ingredients, powdered, and make a plaster.

This plaster stands recommended as a moderately warm diuretic; and is directed by some to be applied to the hypogastric region, for strengthening the viscera, and expelling flatulencies: but it is a matter of great doubt, whether it derives any virtue either from the article from which it is named, or from the caraway or bay-berries which enter its composition.

Fetid, commonly called antihysteric, plaster. E.

Take of common plaster, asafoetida, strained, each two parts; yellow wax, strained galbanum, each one part. Mix, and make them into a plaster.

This plaster is applied to the umbilical region, or over the whole abdomen, in hysterical cases; and sometimes with good effect; but probably more from its giving an additional degree of heat to the part, than from any influence derived from the fetid gums. It has indeed been alleged, that from the application of this plaster to the abdomen, the taste of asafoetida can be distinctly perceived in the mouth; and it is not improbable, that some absorption of its active parts may take place by the lymphatic vessels of the surface; while, at the same time, the asafoetida thus applied must constantly, in some degree, act on the nerves of the nose. But, in both these ways, its influence can be inconsiderable only; and much more effect may be obtained from a very small quantity taken internally. And we are on the whole inclined to think, that the addition of the fetid gums to the common plaster is here more disagreeable than useful.

Ladanum plaster. L.

Take of ladanum, three ounces; frankincense, one ounce; cinnamon powdered, expressed oil, called oil of mace, of each half an ounce; essential oil of spearmint, one dram. To the melted frankincense add first the ladanum, softened by heat; then the oil of mace. Mix these afterwards with the cinnamon and oil of mint, and beat them together in a warm mortar into a plaster. Let it be kept in a close vessel.

This has been considered as a very elegant stomach plaster. It is contrived so as to be easily made occasionally (for these kinds of compositions, on account of their volatile ingredients, are not fit for keeping), and to be but moderately adhesive, so as not to offend the skin, and that it may without difficulty be frequently taken off and renewed; which these sorts of applications, in order to their producing any considerable effect, require to be. But after all, it probably acts more from the mere covering which it gives to the stomach, than from any of the articles abounding with essential oil which it contains.

Litarge-plaster. L.

Take of litharge, in very fine powder, five pounds; olive-oil, a gallon. Boil them with a slow fire, in about two pints of water, constantly stirring until the oil and litharge unite, and have the consistence of a plaster. But it will be proper to add more boiling water, if the water that was first added be nearly consumed before the end of the process.

Common plaster. E.

Take of litharge, one part; olive-oil, two parts; boil them, adding water, and constantly stirring the mixture till the oil and litharge be formed into a plaster.

The heat in these processes should be gentle, and the matter kept constantly stirring, otherwise it swells up, and is apt to run over the vessel. If the composition proves discoloured, the addition of a little white lead and oil will improve the colour.

These plasters, which have long been known under the name of Diacylon, are the common application in excoriations of the skin, slight flesh wounds, and the like. They keep the part soft, and somewhat warm, and defend it from the air, which is all that can be expected in these cases from any plaster. Some of our industrious medicine-makers have thought these purposes might be answered by a cheaper composition, and accordingly have added a large quantity of common whitening and hogs lard: this, however, is by no means allowable, not only as it does not stick so well, but likewise as the lard is apt to grow rancid and acrimonious. The counterfeit is distinguishable by the eye.

**Litharge plaster with gum. L**

Take of litharge-plaster, three pounds; strained galbanum, eight ounces; turpentine, ten drams; frankincense, three ounces. The galbanum and turpentine being melted with a slow fire, mix with them the powdered frankincense, and afterwards the litharge-plaster melted with a very slow fire, and make a plaster.

**Gum-plaster. E.**

Take of common plaster, eight parts; gum-ammoniacum strained, strained galbanum, yellow wax, each one part. Make them into a plaster according to art.

Both these plasters are used as digestives and suppuratives; particularly in abscesses, after a part of the matter has been matured and discharged, for suppurating or dissolving the remaining hard part; but it is very doubtful whether they derive any advantage from the gums entering their composition.

**Litharge-plaster with quicksilver. L**

Take of litharge-plaster, one pound; purified quicksilver, three ounces; sulphurated oil, one dram, or what is sufficient. Make the plaster in the same manner as the ammoniacum-plaster with quicksilver.

**Mercurial or blue plaster. E.**

Take of olive-oil, white resin, each one part; quicksilver, three parts; common plaster, six parts. Melt the oil and resin together, and when this mixture is cold, let the quicksilver be rubbed with it till the globules disappear; then add by degrees the common plaster, melted, and let the whole be accurately mixed.

These mercurial plasters are looked on as powerful resolvents and diuretics, acting with much greater certainty for these intentions than any composition of vegetable substances alone; the mercury exerting itself in a considerable degree, and being sometimes introduced into the habit in such quantity as to affect the mouth. Pains in the joints and limbs from a general cause, nodes, tophi, and beginning indurations of the glands, are said sometimes to yield to them.

**Litharge plaster with resin. L**

Take of litharge-plaster, three pounds; yellow resin, half a pound. Mix the powdered resin with litharge plaster, melted with a very slow fire, and make a plaster.

**Sticking-plaster. E.**

Take of common plaster, five parts; white resin, one

---

**Plaster of Burgundy pitch. L**

Take of Burgundy pitch, two pounds; ladanum, one pound; yellow resin, yellow wax, of each four ounces; the expressed oil, commonly called the oil of mace, one ounce. To the pitch, resin, and wax, melted together, add first the ladanum, and then the oil of mace.

This plaster was at one time much celebrated under the title of cephalic plaster, the name which it formerly held in our pharmacopoeias. It was applied in weakness or pains of the head, to the temples, forehead, &c. and sometimes likewise to the feet. Schulze relates, that an inveterate rheumatism in the temples, which at times extended to the teeth, and occasioned intolerable pain, was completely cured in two days by a plaster of this kind (with the addition of a little opium) applied to the part, after many other remedies had been tried in vain. He adds, that a large quantity of liquid matter exuded under the plaster in drops, which were so acrid as to corrode the cuticle: but it is probable, that this was much more the effect of the Burgundy pitch than of any other part of the composition; for when applied to very tender skin, it often produces even vesication, and in most instances operates as a rubefacient or hot plaster: and as far as it has any good effect in headache, it is probable that its influence is to be explained on this ground.

**Soap-plaster. L**

Take of soap, half a pound; litharge-plaster, three pounds; mix the soap with the melted litharge-plaster, and boil them to the thickness of a plaster.

**Saponaceous plaster. E.**

Take of common plaster, four parts; gum-plaster, two parts; Castile soap, scraped, one part. To the plasters, melted together, add the soap; then boil for a little, so as to form a plaster.

These plasters have been supposed to derive a resolvent power from the soap; and in the last, the addition of the gums is supposed to promote the resolvent virtue of the soap: but it is a matter of great doubt, whether they derive any material advantage from either addition.

**Frankincense plaster. L.**

Take of frankincense, half a pound; dragon's blood, three ounces; litharge-plaster, two pounds. To the melted litharge-plaster add the resin, powdered.

This plaster had formerly in the London pharmacopoeia the title of strengthening plaster, and is a reformation of the complicated and injudicious composition described in the former pharmacopoeias, under the title of Emplastrum ad herniam. Though far the most elegant and simple, it is as effectual for that purpose as any of the medicines of this kind. If constantly worn with a proper bandage, it will, in children, frequently do service; though, perhaps, not so much from any strengthening quality of the ingredients, as from its being a soft, close, and adhesive covering. It has been supposed that plasters composed of styptic medicines constringe and strengthen the part to which they are applied, but on no very just foundation; for plasters in general relax rather than constringe, the unctuous ingredients necessary in their composition counteracting and destroying the effect of the others.

Defensive or strengthening plaster. E.

Take of common plaster, twenty-four parts; white resin, six parts; yellow-wax, oil olive, each three parts; colcothar of vitriol, eight parts. Grind the colcothar with the oil, and then add it to the other ingredients previously melted.

This plaster is laid round the lips of wounds and ulcers over the other dressings, for defending them from inflammation and a fluxion of humours; which, however, as Mr Sharp very justly observes, plasters, on account of their consistence, tend rather to bring on than to prevent. It is also used in weaknesses of the large muscles, as of the loins; and its effects seem to proceed from the artificial mechanical support given to the part, which may also be done by any other plaster that adheres with equal firmness.

Deadly night-bloode plaster. Brun.

Take of the juice of the recent herb of belladonna, linseed oil, each nine ounces; yellow-wax, fix ounces; Venice turpentine, fix drams; powder of the herb of belladonna, two ounces. Let them be formed into a plaster according to art.

There can be no doubt that the belladonna, externally applied, has a very powerful influence, both on the nerves and blood vessels of the part; and thus it has very considerable effect both on the circulation and state of sensibility of the part; and when applied under the form of this plaster, especially in affections of the mammae and scrotum, it has been said to have very powerful influence in alleviating pain, in discharging tumors, and in promoting a favourable suppuration. It has however been but little employed in this country; and we can say nothing of it from our own experience.

Corn plaster. Dan.

Take of galbanum, dissolved in vinegar, and again infusified, one ounce; pitch, half an ounce; diachylon, or common plaster, two drams. Let them be melted together; and then mix with them verdigris powdered, sal ammoniac, each one scruple; and make them into a plaster.

Of this plaster, as well as the former, we can say nothing from our own experience. It has been celebrated for the removal of corns, and for alleviating the pain which they occasion; and it is not improbable that it may sometimes have a good effect from the corrosive articles which it contains; but in other cases, from this very circumstance, it may tend to aggravate the pain, particularly in the first instance.

Hemlock plaster. Suec.

Take of yellow wax, half a pound; oil olive, four ounces; gum-ammoniacum, half an ounce: after they are melted together, mix with them powdered herb of hemlock, half a pound.

This corresponds very nearly with the Emplastrum de cicuta cum ammoniace, which had formerly a place in our pharmacopoeias, and was supposed to be a powerful cooler and difficent, and to be particularly serviceable against swellings of the spleen and distensions of the hypochondres. For some time past, it has been among us entirely neglected; but the high solvent power which Dr Stoerk has discovered in hemlock, and which he found it to exert in this as well as in other forms, intitle it to further trials. The plaster appears very well contrived, and the additional ingredients well chosen for assiting the efficacy of the hemlock.

Corrosive plaster. Gen.

Take of corrosive sublimate mercury, half a dram; hogs lard, half an ounce; yellow wax, two drams. Mix them according to art.

There can be no doubt that the muriated mercury here employed is a very powerful corrosive; and there may be some cases in which it is preferable to other articles of the tribe of caustics: but this would seem to be a very uneconomical mode of applying it, as but a very small portion of what enters the plaster can act; and even that portion must have its action much restrained by the unctuous matters with which it is combined.

Plaster of fenugreek, or of mucilages. Gen.

Take of fenugreek-seed, two ounces; linseed-oil, warm, half a pound. Infuse them according to art, and strain; then take of yellow wax, two pounds and an half; gum-ammoniac, strained, fix ounces; turpentine, two ounces. Melt the gum-ammoniac with the turpentine, and by degrees add the oil and wax, melted in another vessel, so as to form a plaster.

This plaster had formerly a place in our pharmacopoeias, but was rejected; and although still held in esteem by some, it is probably of no great value; at least it would seem to derive but little either from the fenugreek seed, with which it is now made, or from the oil and mucilages which formerly entered its composition.

Henbane-plaster. Suec.

This is directed to be prepared in the same manner as the emplastrum e conio, or hemlock-plaster.

From the well-known sedative power of this plant, as affecting the nervous energy of the part to which it is applied, we might reasonably conclude that good effects may be obtained from it when used under the form of plaster; and accordingly it has been with advantage employed in this manner, for allaying pain, and resolving swelling, in cases of scirrhus and cancer.

Pitch-plaster. Ross.

Take of white resin, six ounces; ship-pitch, seven ounces; yellow wax, five ounces. Melt them, and form them into a plaster.

Pitch, applied externally, has been supposed to act on two principles, by its warmth and by its adhesive quality. quality. In the former way it may have some effect; but it has much more influence in the latter; and particularly it has thus been found to produce a cure in cases of tinea capitis. When a pitch plaster is applied to the affected part of the hairy scalp, and allowed to remain there for a few days, it becomes so attached to the parts, that it cannot be removed without bringing with it the bulbs of the hair in which the disease is seated: and by this means a radical cure is not unfrequently obtained, after every other remedy has been tried in vain. But the cure is a painful one, and not without danger; for in some instances, inflammations, even of an alarming nature, have been excited by the injury thus done to the parts. Hence this mode of cure is rarely had recourse to till others have been tried without effect: and when it is employed, if the disease be extensive, prudent practitioners direct its application only to a small portion at a time, the size of a crown-piece or so; and after one part is fully cured, by application to another in succession, the affection may be soon completely overcome. With this intention it is most common to employ the pitch in its pure state: but the plaster here directed, while it is no less adhesive, is more manageable and flexible.

**Chap. XXXII. Ointments and Liniments.**

Ointments and liniments differ from plasters little otherwise than in consistence. Any of the official plasters, diluted with so much oil as will reduce it to the thickness of stiff honey, forms an ointment: by farther increasing the oil, it becomes a liniment.

In making these preparations, the Edinburgh college direct, that fat and resinous substances are to be melted with a gentle heat; then to be constantly stirred, sprinkling in at the same time the dry ingredients, if any such are ordered, in the form of a very fine powder, till the mixture on diminishing the heat becomes stiff.

It is to be understood that the above general directions are meant to apply to each particular composition contained in the present edition of the Edinburgh pharmacopoeia. It is also to be observed, that where any compositions are ordered, as bases or ingredients of others, the college always refer to those made according to their own formula.

**Ointment of hog's lard. L.**

Take of prepared hog's lard, two pounds; rose-water, three ounces. Beat the lard with the rose-water until they be mixed; then melt the mixture with a slow fire, and set it apart that the water may subside; after which, pour off the lard from the water, constantly stirring until it be cold.

In the last edition of the London pharmacopoeia, this was styled Unguentum simplex, the name given by the Edinburgh college to the following.

**Simple ointment. E.**

Take of olive oil, five parts; white wax, two parts.

Both these ointments may be used for softening the skin and healing chaps. The last is, however, preferable, on account of its being of one uniform consistence. For the same reason it is also to be preferred as the basis of other more compounded ointments.

**Ointment of verdigris. E.**

Take of basilicon ointment, fifteen parts; verdigris, one part.

This ointment is used for cleansing sores, and keeping down fungous flesh. Where ulcers continue to run from a weakness in the vessels of the part, the tonic powers of copper promise considerable advantage.

It is also frequently used with advantage in cases of ophthalmia, depending on scrofula, where the palpebrae are principally affected; but when it is to be thus applied, it is in general requisite that it should be somewhat weakened by the addition of a proportion of simple ointment or hog's lard. An ointment similar to the above, and celebrated for the cure of such instances of ophthalmia, has long been sold under the name of Smellon's eye-salve.

**Ointment of the white calx of quicksilver. L.**

Take of the white calx of quicksilver, one dram; ointment of hog's lard, one ounce and a half. Mix, and make an ointment.

This is a very elegant mercurial ointment, and frequently used in the cure of obstinate and cutaneous affections. It is an improvement of the ointment of precipitated mercury of the last London pharmacopoeia; the precipitated sulphur being thrown out of the composition, and the quantity of mercury increased.

**Ointment of calx of zinc. E.**

Take of simple liniment, six parts; calx of zinc, one part.

This ointment is chiefly used in affections of the eye, particularly in those cases where redness arises rather from relaxation than from active inflammation.

**Ointment of Spanish flies. L.**

Take of Spanish flies, powdered, two ounces; distilled water, eight ounces; ointment of yellow resin, eight ounces. Boil the water with the Spanish flies to one half, and strain. To the strained liquor add the ointment of yellow resin. Evaporate this mixture in a water-bath, saturated with sea-salt, to the thickness of an ointment.

**Epispastic ointment from infusion of cantharides. E.**

Take of cantharides, white resin, yellow wax, each one ounce; hog's lard, Venice turpentine, each two ounces; boiling water, four ounces. Infuse the cantharides in the water, in a clofe vessel, for a night; then strongly press out and strain the liquor, and boil it with the lard till the water be consumed; then add the resin, wax, and turpentine, and make the whole into an ointment.

These ointments, containing the soluble parts of the cantharides, uniformly blended with the other ingredients, are more commodious, in general occasion less pain, and are no less effectual in some cases, than the compositions with the fly in substance. This, however, does does not uniformly hold; and accordingly the Edinburgh college, with propriety, still retain an ointment containing the flies in substance.

Epispaftic ointment, from powder of cantharides. E.

Take of basilicon ointment, seven parts; powdered cantharides, one part.

This ointment is employed in the dressings for blisters, intended to be made perpetual, as they are called, or to be kept running for a considerable time, which in many chronic, and some acute cases, is of great service. Particular care should be taken, that the cantharides employed in these compositions be reduced to a very fine powder, and that the mixture be made as equal and uniform as possible. But with these precautions, there are some particular habits in which this ointment operates with even less pain than the former, while at the same time it is generally more effectual.

Wax ointment. L.

Take of white wax, four ounces; spermaceti, three ounces; olive-oil, one pint. Stir them, after being melted with a slow fire, constantly and briskly, until cold.

This ointment had formerly the title of unguentum album in the London pharmacopoeia. It differs very little from the simple ointment of the Edinburgh pharmacopoeia, and in nothing from the ointment of spermaceti of the London pharmacopoeia, excepting that in this ointment the proportion of spermaceti is somewhat less. It is an useful cooling ointment for excoriations and other frettings of the skin.

Ointment of acetated ceruse. L.

Take of acetated ceruse, two drams; white wax, two ounces; olive-oil, half a pint. Rub the acetated ceruse, previously powdered, with some part of the olive-oil; then add it to the wax, melted with the remaining oil. Stir the mixture until it be cold.

Saturnine ointment. E.

Take of simple ointment, twenty parts; sugar of lead, one part.

Both these ointments are useful coolers and desiccatives; much superior both in elegance and efficacy to the nutritium or tripharmacum, at one time very much celebrated.

Ointment of ceruse, commonly called white ointment. E.

Take of simple ointment, five parts; ceruse, one part.

This is an useful, cooling, emollient ointment, of great service in excoriations and other similar frettings of the skin. The ceruse has been objected to by some, on a suspicion that it might produce some ill effects, when applied, as these unguents frequently are, to the tender bodies of children. Though there does not seem to be much danger in this external use of ceruse, the addition of it is the less necessary here, as we have another ointment containing a more active preparation of the same metal, the saturnine ointment just mentioned; which may be occasionally mixed with this, or employed by itself, in cases where saturnine applications are wanted.

Ointment of elemi. L.

Take of elemi, one pound; turpentine, ten ounces; mutton-fuet, prepared, two pounds; olive-oil, two ounces. Melt the elemi with the fuet; and having removed it from the fire, mix it immediately with the turpentine and oil, after which strain the mixture.

This ointment, perhaps best known by the name of linimentum arcei, has long been in use for digesting, cleansing, and incarnating; and for these purposes is preferred by some to all the other compositions of this kind.

These, however, are much more processes of nature than of art; and it is much to be doubted whether it has in reality any influence.

Ointment of white hellebore. L.

Take of the root of white hellebore, powdered, one ounce; ointment of hog's lard, four ounces; essence of lemons, half a scruple. Mix them, and make an ointment.

White hellebore externally applied has long been celebrated in the cure of cutaneous affections; and this is perhaps one of the best formulas under which it can be applied, the hog's-lard ointment serving as an excellent basis for it, while the essence of lemons communicates to it a very agreeable smell.

Stronger ointment of quicksilver. L.

Take of purified quicksilver, two pounds; hog's lard, prepared, twenty-three ounces; mutton-fuet, prepared, one ounce. First rub the quicksilver with the fuet and a little of the hog's lard, until the globules disappear; then add what remains of the lard, and make an ointment.

Weaker ointment of quicksilver. L.

Take of the stronger ointment of quicksilver, one part; hog's lard, prepared, two parts. Mix them.

Quicksilver, or blue ointment. E.

Take of quicksilver, mutton-fuet, each one part; hog's lard, three parts. Rub them carefully in a mortar till the globules entirely disappear.

This ointment may also be made with double or triple the quantity of quicksilver.

These ointments are principally employed, not with a view to their topical action, but with the intention of introducing mercury in an active state into the circulating system. And this may be effected by gentle friction on the sound skin of any part, particularly on the inside of the thighs or legs. For this purpose, these simple ointments are much better suited than the more compounded ones with turpentine and the like, formerly employed. For by any acid substance topical inflammation is apt to be excited, preventing farther friction, and giving much uneasiness. To avoid this, it is necessary, even with the mildest and weakest ointment, somewhat to change the place at which the friction is performed. But by these ointments properly managed, mercury may in most instances be as advantageously introduced, either for eradicating syphi- lis, or combating other obstinate diseases, as under any form whatever. But to obtain these effects, it is requisite that the ointment should be prepared with very great care: for upon the degree of trituration which has been employed, the activity of the mercury must entirely depend. The addition of the mutton-fat, now adopted by both colleges, is an advantage to the ointment, as it prevents it from running into the state of oil, which the hog's lard alone in warm weather, or in a warm chamber, is sometimes apt to do, and which is followed by a separation of parts. We are even inclined to think, that the proportion of fat directed by the London college is too small for this purpose, and indeed seems to be principally intended for the more effectual trituration of the mercury: But it is much more to be regretted, that, in a medicine of such activity, the two colleges should not have directed the same proportion of mercury to the fatty matter. For although both have directed ointments of different strength, neither the weakest nor the strongest agree in the proportion of mercury which they contain.

Ointment of nitrated quicksilver. L.

Take of purified quicksilver, one ounce; nitrous acid, two ounces; hog's lard, prepared, one pound. Dissolve the quicksilver in the nitrous acid; and, while it is yet hot, mix it with the hog's lard, previously melted, and just growing cold.

Yellow ointment. E.

Take of quicksilver, one ounce; spirit of nitre, two ounces; hog's lard, one pound. Dissolve the quicksilver in the spirit of nitre, by digestion in a sand-pan heat; and, while the solution is very hot, mix with it the lard, previously melted by itself, and just beginning to grow stiff. Stir them briskly together, in a marble mortar, so as to form the whole into an ointment.

These ointments differ only in name; and that employed by the London college is certainly the preferable appellation: For here the quicksilver, previous to its union with the lard, is brought to a saline state by means of the nitrous acid. And although its activity be very considerably moderated by the animal fat with which it is afterwards united, yet it still affords us a very active ointment; and as such it is frequently employed with success in cutaneous and other topical affections. In this condition, however, the mercury does not so readily enter the system as in the preceding form. Hence it may even be employed in some cases with more freedom; but in other instances it is apt to excoriate and inflame the parts. On this account a reduction of its strength is sometimes requisite; and it is often also necessary, from the hard consistence which it acquires, in consequence of the action of acid on the lard.

Tar ointment.

Take of tar, mutton-fat prepared, each half a pound. Melt them together, and strain. L.

Take of tar, five parts; yellow wax, two parts. E.

These compositions, though the one be formed into an ointment by means of fat, the other by wax, cannot be considered as differing essentially from each other. As far as they have any peculiar activity, this entirely depends on the tar. And this article, from the empyreumatic oil and saline matters which it contains, is undoubtedly, as well as turpentine, of some activity. Accordingly, it has been successfully employed against some cutaneous affections, particularly those of domestic animals. At one time, as well as the black basilicon, it was a good deal employed as a dressing even for recent wounds. But although it still retains a place in our pharmacopoeias, it is at present little used with any intention.

Ointment of yellow resin. L.

Take of yellow resin, yellow wax, each one pound; olive oil, one pint. Melt the resin and wax with a slow fire; then add the oil, and strain the mixture while hot.

Basilicon ointment. E.

Take of hog's lard, eight parts; white resin, five parts; yellow wax, two parts.

These are commonly employed in dressings, for digesting, cleansing, and incarnating wounds and ulcers. They differ very little, if at all, in their effects, from the linimentum arcet, or ointment of elemi, as it is now more properly styled. But it is probable that no great effect is to be attributed to either: For there can be no doubt that the suppurative and adhesive inflammation are processes of nature, which will occur without the aid of any ointment.

Elder ointment. L.

Take of elder flowers, four pounds; mutton-fat, prepared, three pounds; olive-oil, one pint. Boil the flowers in the fat and oil, first melted together, till they be almost crisp; then strain with expression.

This ointment does not seem superior to some others, which are much neater, and less expensive. It can scarcely be supposed to receive any considerable virtue from the ingredient from which it takes its name. And accordingly it is not without propriety that it is rejected from the pharmacopoeia of the Edinburgh college.

Ointment of spermaceti. L.

Take of spermaceti, six drams; white wax, two drams; olive-oil, three ounces. Melt them together over a slow fire, stirring them constantly and briskly until they be cold.

This had formerly the name of white liniment, and it is perhaps only in confidence that it can be considered as differing from the simple ointment already mentioned, or the simple cerate afterwards to be noticed.

Sulphur ointment. L.

Take of ointment of hog's lard, half a pound; flowers of sulphur, four ounces. Mix them, and make an ointment.

Ointment of sulphur, or antiporic ointment. E.

Take of hog's lard, four parts; sulphur, beat into a very very fine powder, one part. To each pound of this ointment add essence of lemons, or oil of lavender, half a dram.

Sulphur is a certain remedy for the itch, and safer than mercury. Sir John Pringle observes, that unless a mercurial unction was to touch every part of the skin, there can be no certainty of success; whereas, from a sulphureous one, a cure may be obtained by only partial unctio; the animalcula, which are supposed to occasion this disorder, being, like other insects, killed by the sulphureous steams which exhale by the heat of the body. As to the internal use of mercury, which some have accounted a specific, there are several instances of men undergoing a complete salivation for the cure of the lues venerae, without being freed from the itch; but there are also a multitude of instances of men undergoing a long course of sulphur without effect, and who were afterwards readily cured by mercury.

The quantity of ointment, above directed, serves for four unctious: the patient is to be rubbed every night; but to prevent any disorder that might arise from stopping too many pores at once, a fourth part of the body is to be rubbed at one time. Though the itch may thus be cured by one pot of ointment, it will be proper to renew the application, and to touch the parts most affected for a few nights longer, till a second quantity also be exhausted; and in the worst cases, to subjoin the internal use of sulphur, not with a view to purify the blood, but to diffuse the steams more certainly through the skin; there being reason to believe, that the animalcula may sometimes lie too deep to be thoroughly destroyed by external applications.

**Tutty ointment.**

Take of prepared tutty, one dram; ointment of spermaceti, what is sufficient. Mix them so as to make a soft ointment. L.

Take of simple liniment, five parts; prepared tutty, one part. E.

These ointments have long been celebrated, and are still much employed against affections of the eyes. But they cannot, we imagine, be esteemed elegant.

Both calamine and tutty act only by means of the zinc they contain, and calamine appears to contain the most of the two, and likewise to be the least variable in its contents. But the pure flowers prepared from zinc itself are doubtless preferable to either. Hence the ointment of tutty may be considered as inferior to both the ointment of calamine and to the ointment of the calx of zinc, which have also a place in our pharmacopoeia.

**Simple liniment. E.**

Take of olive oil, four parts; white wax, one part.

This consists of the same articles which form the simple ointment of the Edinburgh pharmacopoeia, but merely in a different proportion, so as to give a thinner consistence; and where a thin consistence is requisite, this may be considered as a very elegant and useful application.

**Liniment of ammonia. L.**

Take of water of ammonia, half an ounce; olive-oil, one ounce and an half. Shake them together in a phial till they are mixed.

This has long been known in the shops under the title of volatile liniment, but is now more properly denominated from the principal active article, which enters its composition. It has been much employed in practice, particularly on the recommendation of Sir John Pringle in his Observations on the Diseases of the Army. He observes, that, in the inflammatory quinsey, or strangulation of the fauces, a piece of flannel, moistened with this mixture, applied to the throat, and renewed every four or five hours, is one of the most efficacious remedies. By means of this warm stimulating application, the neck, and sometimes the whole body, is put into a sweat, which after bleeding either carries off or lessens the inflammation. Where the skin cannot bear the acrimony of this mixture, a larger proportion of oil may be used.

**Stronger liniment of ammonia. L.**

Take of water of pure ammonia, one ounce; olive-oil, two ounces. Shake them together in a phial.

This article differs from the foregoing in strength only. This arises both from its being formed of a more acid spirit, and from its containing that spirit in a larger proportion to the oil. It is used to supply the place of the epibema et emplastrum volatile of our former pharmacopoeias, and is a very acid stimulating composition. When largely applied, it often excites inflammation, and even vesication, on tender skin. It is often, however, successfully employed against obstinate rheumatic and sciatic pains.

**Camphor liniment. L.**

Take of camphor, two ounces; water of ammonia, six ounces; simple spirit of lavender, fifteen ounces.

Mix the water of ammonia with the spirit, and distil from a glass retort, with a slow fire, fifteen ounces. Then dissolve the camphor in the distilled liquor.

This formula, which has now for the first time a place in the London pharmacopoeia, approaches to the volatile essence of that celebrated empiric the late Dr Ward: But the above is a more elegant and active formula than either of the receipts published by Mr Page, from Dr Ward's book of receipts; and there is no reason to doubt that it will be equally effectual in removing some local pains, such as particular kinds of headache, in consequence of external application.

**Soap-liniment. L.**

Take of soap, three ounces; camphor, one ounce; spirit of rosemary, one pint. Digest the soap in the spirit of rosemary until it be dissolved, and add to it the camphor.

This is the soap liniment of the former edition of the London pharmacopoeia, without any alteration; and it differs very little from the soap-balsam of the Edinburgh college already mentioned. Though a less active and penetrating application than the preceding, it is perhaps no less useful: and it is often successfully employed for external purposes against rheumatic pains, sprains, bruises, and similar complaints. Egyptian ointment. Gen.

Take of honey, one pound; strong vinegar, half a pound; verdigris, powdered, five ounces. Let the ingredients be boiled together till the verdigris be dissolved, so that the ointment may have a due degree of thickness and a purple colour.

This preparation had formerly a place in our pharmacopoeias under the title of Egyptian honey; and a similar preparation has now a place under the title of oxymel of verdigris. But in that formula the proportion is much less than in the above. It may justly be considered as a very powerful application for cleansing and deterring foul ulcers, as well as for keeping down fungous flesh. But these purposes may in general be answered by articles less acrid, and exciting less pain. Besides this, the above preparation is also liable to considerable uncertainty with respect to strength; for a large proportion of the verdigris will in a short time subside to the bottom; thus, what is in the top of the pot is much less active than that in the bottom.

Anodyne ointment. Gen.

Take of olive-oil, ten drams; yellow wax, half an ounce; crude opium, one dram. Mix them according to art, so as to form an ointment.

Opium thus externally applied, will in some degree be productive of the same effect as when used under the form of the anodyne balsam. In that state it produces its effects more immediately; but under the present form its effects are more permanent. Besides this, the present ointment furnishes us with an useful dressing for sores attended with severe pain; to which opium when dissolved in spirit cannot be applied. Hence the present, or some analogous formula, is well intitled to a place in our pharmacopoeias.

Ointment for an ulcerated cancer. Brun.

Take of the recently expressed juice of the ricinus, one pound: let it be exposed to the rays of the sun in a leaden vessel till it acquire the consistence of an oil; then to one pound of this infusified juice add calcined lead, white precipitate mercury, each one pound. Let them be properly mixed.

This acrid application must possess a considerable degree of corrosive power. And in some cases of cancer, by the proper application of corrosives, much benefit may be done: But where the disease has made any considerable progress, these will in general have the effect rather of hastening its progress than of removing it; particularly if there be a large indolent tumor below the ulcer.

Digestive ointment. Roff.

Take of Venice turpentine, one pound; the yolks of eight eggs. Mix them together according to art.

This warm stimulating application is well suited to promote the suppurative inflammation, and may be advantageously had recourse to, where it is necessary to encourage a large discharge of pus.

Haemorrhoidal ointment.

Take saturnine ointment, six drams; oil of hyoscyamus, obtained by boiling, two drams; camphor, powdered, two scruples; saffron, one scruple. Mix them into an ointment.

The name affixed to this ointment expresses the purpose for which it is applied. From the articles of which it consists, it may be concluded, that it possesses a gently emollient and anodyne power; and may therefore afford considerable relief, where much pain arises from external haemorrhoidal tumors.

Laurel ointment. Suec.

Take of prepared mutton-fat, eight ounces. After it is melted and removed from the fire, add to it oil of bays, one pound; ethereal oil of turpentine, one ounce; rectified oil of amber, half an ounce. Let them be mixed and rubbed together till they form an ointment.

This is an improved mode of forming an ointment which had formerly a place in our pharmacopoeias under the title of nervine ointment. And it furnishes a warm stimulating nervine application, which may in some degree restore sense and motion to paralytic limbs. And while it at least serves to lead to the careful use of friction, it may somewhat increase the benefit which would result from it.

Ointment of tobacco. Dan.

Take of the leaves of tobacco, three pounds; juice of tobacco, nine ounces; hog's lard, a pound and a half; resin, three ounces. Let the cut leaves be macerated for the space of a night, and then boiled over a gentle fire. Having strained the fluid obtained by expression, add to it yellow wax, half an ounce; powder of the root of birthwort, three ounces. Mix them into an ointment.

There can be no doubt that tobacco externally applied has very powerful effects on the human body; and that not merely from its topical action, but sometimes even as affecting the system in general. From this last circumstance it requires to be used with great caution. It has, however, been found, under proper management, to afford an effectual cure in obstinate cutaneous affections. But were it to be used with this intention, we would have a more elegant formula, by merely impregnating either hog's lard, or the simple ointment, with the active qualities extracted by the aid of heat from the leaves of the prepared tobacco in the state in which it is usually brought to us from America, than by having recourse to the recent juice, and to the aristolochia and other additions here directed.

Ointment of storax. Succ.

Take of olive oil, a pound and a half; white resin, gum elemi, yellow wax, each seven ounces. After they are melted together and strained, add liquid storax, seven ounces. Mix them together, and agitate the mixture till it concretes into an uniform ointment.

An ointment supposed to derive its activity from the storax, although it have no place in our pharmacopoeias, is received into most of the foreign ones. And it has been much celebrated not only as a strengthening application to weakly children, but even for the removal of affections of the bones, as in cases of rachitis. tis and the like. It is, however, very doubtful how far these properties depend on the florax. If it have really any good effect, it is probable that this is more the consequence of the friction merely, than of any of the articles which enter the composition of the ointment. But there is reason to believe that the virtues attributed to this ointment are more imaginary than real.

**Onion ointment. Suec.**

Take of yellow wax, resin, each half a pound. To these melted, add onions roasted under the ashes, honey, each two pounds and a half; black soap, half a pound. Let them be gently boiled together till all the moisture be consumed, then strain the liquor, expressing it from the materials, and afterwards agitate it with a wooden pestle that it may unite into one uniform mass.

This ointment is applied with the intention of promoting suppuration. And it has long been supposed, that the onion, especially in its roasted state, has a remarkable influence in this way: but there is reason to think, that the powers attributed to it have been greatly over-rated. And there is even ground to presume that these effects totally depend entirely on heat and moisture. Hence no application is perhaps better suited for promoting suppuration than a poultice of bread and milk, applied as hot as can be borne with and frequently repeated.

**CHAP. XXXIII. Cerates.**

Cerates are substances intended for external application, formed of nearly the same materials which constitute ointments and plasters. And they differ principally from these in being merely of an intermediate consistence between the two. Accordingly, they are seldom the subject of a separate chapter by themselves, but are classified either with the one or the other. In the Edinburgh pharmacopoeia they are classified among the ointments; but as the London college have referred them to a separate head, we shall here also consider them by themselves.

**Simple cerate. E.**

Take of olive oil, six parts; white wax, three parts; spermaceti, one part. Unite them according to art. This differs from the simple ointment in containing a greater proportion of wax to the oil, and in the addition of the spermaceti. But by these means it obtains only a more firm consistence, without any essential change of properties.

**Cerate of cantharides, or Spanish flies. L.**

Take of cerate of spermaceti, softened with heat, six drams; Spanish flies, finely powdered, one dram. Mix them.

Under this form cantharides may be made to act to any extent that is requisite. It may supply the place either of the blistering plaster or ointment; and there are cases in which it is preferable to either. It is particularly more convenient than the plaster of cantharides, where the skin to which the blister is to be applied is previously much affected, as in cases of smallpox; and in supporting a drain under the form of issue, it is less apt to spread than the softer ointment.

**Calamine-cerate. L.**

Take of calamine prepared, yellow wax, each half a pound; olive oil, one pint. Melt the wax with the oil; and, as soon as the mixture begins to thicken, mix with it the calamine, and stir the cerate until it be cold.

**Cerate of calamine. E.**

Take of simple cerate, five parts; calamine prepared, one part.

These compositions are formed on the cerate which Turner strongly recommends in cutaneous ulcerations and excoriations, and which has been usually distinguished by his name. They appear from experience to be excellent epiliotics, and as such are frequently used in practice.

**Cerate of acetated litharge. L.**

Take of water of acetated litharge, two ounces and a half; yellow wax, four ounces; olive oil, nine ounces; camphor, half a dram. Rub the camphor with a little of the oil. Melt the wax with the remaining oil; and as soon as the mixture begins to thicken, pour in by degrees the water of acetated litharge, and stir constantly until it be cold; then mix in the camphor before rubbed with oil.

This application has been rendered famous by the recommendations of Mr Goulard. It is unquestionably in many cases very useful. It cannot, however, be considered as varying essentially from the saturnine ointment, or ointment of acetated ceruse, formerly mentioned. It is employed with nearly the same intentions, and differs from it chiefly in consistence.

**Cerate of yellow resin. L.**

Take of ointment of yellow resin, half a pound; yellow wax, one ounce. Melt them together, and make a cerate.

This had formerly the name of lemon-ointment. It is no otherwise different from the yellow basilicum, or ointment of yellow resin, than being of a stiffer consistence, which renders it for some purposes more commodious.

**Soap cerate. L.**

Take of soap, eight ounces; yellow wax, ten ounces; litharge, powdered, one pound; olive oil, one pint; vinegar, one gallon; boil the vinegar with the litharge over a slow fire, constantly stirring until the mixture unites and thickens; then mix in the other articles, and make a cerate.

This, notwithstanding the name, may rather be considered as another saturnine application; its activity depending very little on the soap; and it may be held as varying in little else but consistence from the plaster of litharge. It can hardly be thought to differ in its properties from the cerate of acetated litharge just mentioned; for neither the small proportion of camphor which enters the composition of the one, nor the soap which gives name to the other, can be considered as having much influence. Cerate of spermaceti. L.

Take of spermaceti, half an ounce; white wax, two ounces; olive oil, four ounces. Melt them together, and stir until the cerate be cold.

This had formerly the name of rubite cerate, and it differs in nothing from the ointment of spermaceti, or white liniment, as it was formerly called, excepting in consistence, both the wax and the spermaceti bearing a greater proportion to the oil.

Lep-falsee. Ross.

Take of olive oil, eighteen ounces; white wax, one pound; spermaceti, an ounce and a half; oil of rhodium, half a dram. Form a cerate, tinged it with alkanet, so as to give a red colour.

The name affixed to this cerate points out the use for which it is intended. It is chiefly employed against those chops and excoriations of the lips, which are often the consequence of cold weather; and it is very well suited for removing affections of that kind. But excepting in the colour and smell which it derives from the alkanet and rhodium, it differs in nothing from the cerate of spermaceti, and cannot be considered as more effectually answering the intention in view.

Bougies. Suec.

Take of yellow wax, melted, one pound; spermaceti, three drams; vinegar of litharge, two drams. Mix them, and upon removal from the fire immerse into the mixture slips of linen, of which bougies are to be formed according to the rules of art. These may also be made with double, triple, or quadruple, the quantity of the vinegar.

It is perhaps rather surprising, that no formula for the preparation of bougies has a place in our pharmacopoeias; for there can be no doubt, that although the preparation of them has hitherto been principally trusted to empirics; yet in the hand of the skilful practitioner they are of great service in combating obstinate affections. Although it has been pretended by some that their influence is to be ascribed to certain impregnations; yet it is on better grounds contended, that they act entirely on mechanical principles. The great object is therefore to obtain the union of a proper degree of firmness and flexibility. These qualities the above composition possesses; and it does not probably derive any material benefit from being prepared with an additional proportion of the vinegar of litharge.

CHAP. XXXIV. Epithems.

By epithems or cataplasms are in general understood those external applications which are brought to a due consistence or form for being properly applied, not by means of oily or fatty matters, but by water or watery fluids. Of these not a few are had recourse to in actual practice; but they are seldom prepared in the shops of the apothecaries; and in some of the best modern pharmacopoeias no formulae of this kind are introduced. The London college, however, although they have abridged the number of epithems, still retain a few. And it is not without some advantage that there are fixed forms for the preparation of them.

Cataplasm of cummin. L.

Take of cummin-seed, one pound; bay-berrys, dry leaves of water-germander, or scordium, Virginian snake-root, of each three ounces; cloves, one ounce. Rub them all together; and, with the addition of three times the weight of honey, make a cataplasm.

This is adopted into the present edition of the London pharmacopoeia with very little alteration from the last. It was then intended as a reformation of the theriaca Londinensis, which for some time past has been scarcely otherwise used than as a warm cataplasm. In place of the numerous articles which formerly entered that composition, only such of its ingredients are retained as contribute most to this intention: but even the article from which it now derives its name, as well as several others which still enter it, probably contribute very little to any medical properties it may possess.

Mustard-cataplasm. L.

Take of mustard seed, powdered, crumb of bread, each half a pound; vinegar, as much as is sufficient. Mix, and make a cataplasm.

Epithems of this kind are commonly known by the name of snapifims. They were formerly not unfrequently prepared in a more complicated state, containing garlic, black-soap, and other similar articles; but the above simple form will answer every purpose which they are capable of accomplishing. They are employed only as stimulants: they often inflame the part and raise blisters, but not so perfectly as cantharides. They are frequently applied to the soles of the feet in the low state of acute diseases, for raising the pulse and relieving the head. The chief advantage they have depends on the suddenness of their action.

Alum-curd. L.

Take the whites of two eggs; shake them with a piece of alum till they be coagulated.

This preparation is taken from Riverius. It is a useful astringent epithem for sore, moist eyes, and excellently cools and refreshes thin defluxions. Slighter inflammations of the eyes, occasioned by dust, exposure to the sun, or other similar causes, are generally removed by fomenting them with warm milk and water, and washing them with solutions of white vitriol. Where the complaint is more violent, this preparation, after the inflammation has yielded a little to bleeding, is one of the best external remedies. It is to be spread on lint, and applied at bed-time.

A Table, showing in what Proportions Mercury or Opium enter different Formula.

| Formula | Mercury or Opium | |---------|------------------| | Pulvis erecta compositus cum opio. L. | In about forty-four grains, one grain of opium is contained. | | Pulvis specuanae compositus. L. | In ten grains, one grain of opium. | | Pulvis sudorificus. E. | In eleven grains, one grain of opium. | | Pulvis opiatus. L. | In ten grains, one grain of opium. | | Pulvis e scammonio cum calomelane. L. | In four grains, one grain of calomel. |

3 K Pilula ex opio. L. In five grains, one grain of opium.

Pilula thebaicae. E. In ten grains, one grain of opium.

Pilula ex hydrargyro. L. In two grains and a half, one grain of mercury.

Pilula ex hydrargyro. E. In four grains, one grain of mercury.

Pilula plummeri. E. In two grains and two-thirds, one grain of calomel.

Confectio opiata. L. In thirty-six grains, one grain of opium.

Electuarium Japonicum. E. In about one hundred and ninety-three grains, one grain of opium.

Electuarium Thebaicum. E. In ninety-seven grains, one grain of opium.

Trochisci bechici cum opio. E. In fifty-five grains, one grain of opium.

These trochisci are not unfrequently ordered cum duplici opio, and under this form are kept in many shops.

Emplastrum ammoniacum cum hydrargyro. L. In five ounces, one ounce of mercury.

Emplastrum lythargyri cum hydrargyro. L. In five ounces, one ounce of mercury.

Emplastrum e hydrargyro. E. In three ounces and two-thirds, one ounce of mercury.

Unguentum hydrargyri fortius. L. In two drams, one dram of mercury.

Unguentum hydrargyri mitius. L. In five drams, one dram of mercury.

Unguentum ex hydrargyro. E. In five drams; one dram of mercury.

Unguentum hydrargyri nitrati. L. In one dram, four grains of nitrated quicksilver.

Unguentum cirinum. E. In one dram, four grains of nitrated quicksilver.

Unguentum calcis hydrargyri albae. L. In one dram, four grains and two-thirds of the calx hydrargyri alba.

Tinctura opii (L.) is made with opium, in the proportion of one grain to about thirteen of the menstruum.

Tinctura Thebaica (E.) is made with opium, in the proportion of one grain to twelve of the menstruum.

Tinctura opii camphorata (L.) is made with opium, in the proportion of one grain to two hundred and sixty of the menstruum.

Elixir paregoricum (E.) is made with opium, in the proportion of one grain to sixty-eight of the menstruum.

Balsamum anodynum (E.) is made with opium, in the proportion of one grain to about thirty of the menstruum.

INDEX

Acetated litharge, compound water of, no 610. Cerate of, 673. Ointment of acetated ceruse, 643. Acetous fermentation, 16, 17. Acid, 202. Aerated water, 205. Athiops martial, 281. Mineral, 300. Acid, carbonic, 12. Account of the various acids, 53. As menstrua, 71. On various acids, 196-205. Acid julep, 490. Of syrup, 513. Affinities, tables of, p. 290-294. Air, fixed, nature of, no 54. Alcohol, 15. The menstruum of essential oils and resins of vegetables, 73. Alexiterial water, 333. Alkali, fixed vegetable, 24. Acetated fixed vegetable, 235. Tartarized vegetable, fixed, 239. Alkaline salts and earths, &c., dissolved by acids, 75. Lixivia dissolve oils, &c., 76. Fixed vegetable purified, 211. Fixed fossil alkaline salts, &c., 220. Syrup, 514. Allspice water, 328. Spirit of, 362. Almonds, oil of, no 152. Milk, 482. Syrup of, 516. Aloe, watery extract of, 148. Wine of, 408. Tincture of, 421. Compound do, 422. Vitriolic elixir of do, 423. Elixir of, 458. Pills of, 571. Do. with myrrh, 572. Aleotic wine, 408. Powder, 530. Do. with iron, 531. Do. with guaiacum, 532. Alum, purification of, 242. Burnt, 243. Compound, water of, 607. Amalgama of tin, 313. Amber, oil and salt of, 178, 206. Purified salt of, 207. Tincture of, 478. Julep, 492. Ammonia, prepared, 221. Water of, 222. Do. of pure, 225. Water of, acetated, 236. Spirit of, 352. Febrifugal spirit of, 353. Compound spirit of, 486. Succinated do, 487. Liniment of, 656. Stronger do. of, 657. Ammoniac, volatile sal, 223. Spirit of sal, 224. Do. with quick-lime, 226. Prepared, 221. Vinous spirit of sal, 352. Iron, 274. Copper, 318. Ammoniacum, gum purification of, no 95. Milk, 484. Plaster with quick-silver, 614. Ammoniated copper, water of, 609. Andromachus, theriac of, 605. Animal oil, 176, 177. Animals, analogy between them and vegetables, 3. Nature of the substance of, 45. Fluid parts, 46. Oils and fats of, 47. Miscellaneous observations on several substances of, 48. Earths of, 51. Anise, essential oil of, 158, 159. Anifeed, essential oil of, 159, 161. Compound spirit of, 354. Anodyne liniment or balm, 470. Ointment, 661. Anthelmintic powder, 549. Antiferic spirit, 370. Antibacterial plaster, 618. Antimonial powder, 260. Wine, 410. Wine of tartar, 411. Antimony, prepared, 91. Preparations of, 254-271. Wine of, 410. Wine of tartarized, 411. Tincture of, 472. Aniphtilisal tincture, 461. Anipforic ointment, 653. Ardent spirit, no 348. Aroma, 35. Aromatic spirit, 369. Vinegar, 400. Tincture, 424. Powder or spices, 533. Confection, 602. Arsenic, mineral solution of, 494. Arum, conserve of, 114. Compound powder, 551. Asafetida, tincture of, 425. Afarabacca, compound powder of, 534. Ash-coloured powder of mercury, 287. Attractions, elective, 55. Table of single explained, 56. Table, p. 292, &c. Cafes of double, p. 294. B. Bacher's pills, 582. Balm water, 342. Compound water of, 366. Balsam of Peru, tincture of, 426; and of Tolu, 427. Traumatic, 428. Anodyne, 470. Saponaceous, 471. Of Tolu, syrup of, or balsamic syrup, 510. Bark, extract of Peruvian, 138. Barley-water, 382. Barley, decoction of, 380. Compound do, 381. Basilicon. of White, 466. Ointment of white, 646.

Hemlock, inspissated juice of, n° 126. Plaster, 630.

Hembane plaster, 633.

Herbar. See Sulphur, &c.

Herbs and flowers, drying of, 97.

Hips, conserve of, 115.

Hogs lard and mutton-fat, preparation of, 94. Ointment of, 636.

Honey, the purifying of, 98. Medicated, 520—529.

Horseradish, compound spirit of, 364.

Horns, rectified oil of, 177.

Hydrogen, 19.

Hyssopam, oil of, 156.

Hyssop water, 340.

Jalap, extract of, 142. Tincture of, 450. Compound powder of, 540. Pills, 577.

Jamaica pepper, essential oil of, 160. 172. Spirituous water of, 362.

Japonic tincture, 435. Electuary or confection, 594.

Infants, powder for, 555.

Infusions and decoctions, 371—407.

Inspissated juices, 123—128.

Ipecacuanha, wine or tincture of, 413. Compound powder of, 539.

Iron, purified filings of, 104. Rust of, prepared, 105. Scales of, purified, 106. Preparations of, 274—283. Wine of, 412. Tincture of, 443. Fillings prepared, 276.

Juice, compound, of scurvy-grass, 122. Inspissated of the elder-berry, 124. Ditto of wolfs-bane, 125. Ditto of hemlock, 126. Ditto of black currants and lemons, 127.

Juices, expression of, 85. Nature of, and way of obtaining, 121. Inspissated, 123—128.

Julep acids, 490. Ether, 491. Amber, 492. Saline mixture, or julep, 493.

July-flower, syrup of, clove of, 498.

Juniper-berry, essential oil of, 159, 160, 169. Compound spirit of, or compound juniper-water, 357.

Kali, prepared, 210. Water of, 212. Ditto of pure, 213.

Pure, 215. Lime with, 217. Vitriolated, 228. Acetated, 234. Tartarized, 238.

Kermes mineral, 269.

L.

Loc, tincture of, 476.

Ladanum plaster, 619.

Lard, hog's, and mutton-fat, preparation of, 94. Ointment of, 636.

Laudanum, liquid, 455.

Lavender, essential oil of, 159. Ditto of the flowering tops of, 160. Ditto of flowers, 163. Simple spirit of, 358. Compound tincture of spirit of, 452.

Lawel ointment, 665.

Lead, preparations of, 305—311. Vinegar of, 402.

Troches of red, 567.

Leaves of wood-sorrel, conserve of, 109. Of spearmint, conserve of, 113.

Lemon-juice, syrup of, 502.

Lemons, inspissated juice of, 127. Essence of, 182. Peel-water, 331.

Lenient linctus, 600.

Lenitive electuary, 593.

Ley, caustic, 214.

Lily-of-the-valley water, 341.

Lime with pure kali, 217.

Lime-water, 398.

Liniment, lenient, 600.

Liniments, asodyne, 470. Saponaceous, 471. And ointments, 635—669.

Lip-delve, 677.

Licorice, refined, 150. Troches of, 562.

Litharge, acetated water of, 310. Compound ditto, 610. Plaster, 620. Ditto with gum, 621. Ditto with quicksilver, 622. Ditto with resin, 623. Cerate of, 673.

Liquor, extract of, 137.

Long digestion, on extracts by, 132.

Lunar caustic, 272. Pills, 273.

M.

Mace, expressed oil of, 154. Essential ditto, 188.

Mad-dog, powder to prevent the poison of the bite, 550.

Magnesia, 248—250. Troches of, 566.

Manna, electuary of, 597.

Marjoram, essential oil of, 189.

Marshmallows, decoction of, 372. Syrup of, 497.

Martial flowers, 275. Ethiops, 281.

Meadow saffron, oxymel of, n° 524.

Measures in pharmacy, 69. Table of the weights of different fluid ones, 70.

Mesonium, syrup of, 503.

Medicated wines, 407—419. Waters, 626—613. Honeys, 520—529.

Melampodium, tincture of, 449.

Menstrua, principal, for solution, 72, &c.

Mercury, preparations of, 283—305. Pills of the corrosive sublimate of, 586.

Mercurial pills, 576. Or blue plaster, 622.

Metallic substances dissolved by acids, 75.

Metals, 52.

Milk, salt or sugar of, 244. Almond, 482. Ammoniacum, 484.

Millipedes, preparation of, 99. Conserve of, 119. Wine of, 414.

Minerarius, spirit of, 237.

Minerals, 49. Mineral earths, 51. Mineral kermes, 269. Mineral solution of arsenic, 494.

Minium. See Lead, &c.

Mint, garden, essential oil of the herbs of, 160. Ditto of leaves of common, 165.

Mitridate, 605.

Mixture, saline or julep, 493.

Mixtures of various kinds, 479—495.

Mucilage, extraction of, 103. Of starch, 388. Of gum-arabic, 389. Plaster of, 632. Of gum tragacanth, 390. Of quince seed, 391.

Mulberry juice, syrup of, 502.

Muricated antimony, 258.

Quicksilver, 289. Mild muricated ditto, 294.

Muratic acid, 199.

Musk, tincture of, 453. Mixture of, 481.

Mustard cataplasm of, 681.

Mutton fat and hog's lard, preparation of, 90.

Myrrh, gummy extract of, 145. Tincture of, 454. Compound powder of, 541. Pilla of aloes with, 572.

N.

Natron, 25. Prepared, 219. Vitriolated, 231. Tartarized, 240.

Nightshade, plaster of deadly, 628.

Nitrated calx of antimony, 256.

O.

Odorous principle of vegetables, 35.

Oil of almonds, 152. Of hartshorn, 227.

Oils, gips, 29. Essential, 31, 32, 33. Of vegetables, rectified spirit of wine a menstruum for, 73. Of the mineral kingdom, 49. Dissolve various substances, 74. Dissolved by alkaline lixivias, 76. Express'd, &c. 151—158. Essential, &c. 158—196. Salt and oil of amber, 178, 206.

Ointments and liniments, 635—669.

Oliver, expressed oil of, 154.

Onion ointment, 668.

Opiate powder, 542.

Opium, purified, 144. Extract of, prepared by long digestion, 145. Tincture of, 455. Camphorated tincture of, 456. Pills, 579. Confection of, 604.

Orange-peel, conserve of the yellow rind of that of Seville, 112. Water, 332, 368. Tincture of, 439. Syrup of, 500.

Orange-skins, essential oil of, 182.

Origaniun, essential oil of, 159. Ditto of leaves of, 166.

Oxymel of verdigris, 523. Of meadow saffron, 524. Of squills, 525. Simple, 526. Of garlic, 527. Pectoral, 528.

P.

Pabulum of vegetables, 4.

Pacific pills, 579.

Palm, expressed oil of, 154.

Panacea of antimony, 270.

Paragoric elixir, 456.

Petral oxymel, 528. White troches, 561. Black ditto, 562. Troches with opium, 563.

Pennyroyal, essential oil of, 159. Ditto INDEX.

Ditto of leaves of, 167. Water, 329. Spirit of, 363. Peppermint, essential oil of, 159, 160. Ditto of leaves, 164. Water, 326. Spirit of, or spirituous water, 359. Peru, tincture of the balsam of, 426. Peruvian bark, extract of, 138, 140. Ditto with resin, 139. Decoction of, 375. Infusion of, 404. Tincture of, 440. Compound ditto, 441. Purging powder, 557. Pharmacy defined, 1. Objects of, 2. Pills, lunar, 273. Of various kinds, and general rules for making, 560—590. Pimento, or allspice, spirit of, 362; or spirituous Jamaica pepper water, ibid. Pitch, plaster of Burgundy, 624. Plaster, 624. Plants, differ in the different periods of their growth, 6. Different part of the same plant of different qualities, 7. Plaster, 613—635. Poppy, syrup of white, 503. Ditto of red, 504. Potash, 23. Powder, antimonial, 260. Ash-coloured of mercury, 287. Powders, manner of making, and various kinds of, 529—560. Powdered tin, 312. Precipitation, 81. Preparation of substances not soluble in water, 90, &c. Of hog's lard and mutton-fat, 94. Of millipeds, 99. Prepared antimony, 91. Calamine, 92. Chalk, 93. Rust or shavings of iron, 105. Kali, 210. Natron, 219. Ammonia, 221. Preps, use of, in expressing juices, 85. Pulps extraction, 100. Purging Peruvian powder, 557. Purification of gum ammoniac, 95. Of honey, 98. Of stonex, 103. Of alum, 242. Purified filings of iron, 104. Scales of iron, 106. Opiums, 144. Fixed fusible alkaline salt, 220. Nitre, 233. Sal ammoniac, 247. Putrefactive fermentation, 18, 19. Quassa, tincture of, 475. Quicksilver, purified, 284. Acetated, 285. Calcined, 286. With chalk, 288. Muriated, 289. Mild nitrated, 294. Red nitrated, 295. White calx of, 297. With sulphur, 299. Red sulphurated, 321. Vitriolated, 302. Syrup of, 519. Pills, 576. Ointment of the white calx of, 638. Stronger ditto, 647. Weaker ditto, ibid.; or blue ointment, ibid. Ointment of nitrated, 648. Quince-seed, mucilage of, 391. R. Raspberry juice, syrup of, 502. Rectified spirit of wine, a menstruum for essential oils and resins of vegetables, 73. On extracts with, 130. Oil of turpentine, 175. Oil of hams, 177. Oil of amber, 179. Red nitrated quicksilver, 295. Corroborate precipitated mercury, 306. Lead, 306. Poppy syrup, 504. Refined liquorice, 150. Reflux, 36. Extracts, &c. 128—151. Resinous substances dissolved by alkaline lixivium, 76. Extract of Peruvian bark with, 139. Ointment of ditto, 674. Rhodium, essential oil of, 187. Rhubarb, infusion of, 397. Wine of, 415. Various tinctures of, 457. Elixir of, 458. Rochel salt, 237. Rob, or infusillated juice of elder berries, 124. Rosin, infusion of, 396. Conserve of the bulbs of red, 111. Vitriolated conserve of, 120. Tincture of, 396. Vinegar of, 401. Syrup of pule, 505. Of dry, 506. Honey of, 521. Water, 330. Rosemary, essential oil of, 159. Ditto of tops of, 160, 163. Spirit of, 365. Rue, essential oil of, 191. Water, 343. Rufus pills, 572. Rust of iron, prepared, 105. 276. S. Saffron, tincture of, 442. Syrup of, 501. Oxymel of meadow, 524. Sage water, 346. Sal ammoniac, volatile, 225. Spirit of, 224. Ditto with quicklime, 226. Saline mixture or julep, 493. Salt and oil of amber, 178, 206. Purified ditto of amber, 207. Of tartar, 209. Fixed vegetable alkaline, 211. Fixed fusible alkalized, purified, 220. Of hartshorn, 227. Of many virtues, 230. Cathartic of Glauber, 232. Rochel, 241. Or sugar of milk, 244. Of forret, 243. Acid of borax, 246. Ammoniac, purified, 247. Of silver, 272. Of steel, 279, &c. Salts, and saline preparations of vegetables, p. 273, no 39, 40, 41. Alkaline, dissolved by acids, 75. Chapter on, &c. 196—248. Salve for lips, 677. Sap of vegetables, 28. Sapphire-coloured water, 609. Saponaceous balsam or liniment, 471. Plaster, 625. Sarsaparilla, decoction of, 384. Compound ditto, 385. Sassafras root, essential oil of, 159, and 170. Saturnine ointment, 643. Savin, essential oil of, 160. Ditto of leaves of, 171. Water, 344. Compound tincture of, 459. Savory, essential oil of, 192. Scales of iron purified, 106. Scammony, compound powder of, 543. Ditto with aloes, 544. Ditto with calomel, 545. Electuary of, 592. Scurvy-grass, spirit of, 367. Sebaceous matter, 30. Seneka, decoction of, 386. Senna, extract of, 143. Simple infusion of, 393. Tartarized ditto, 394. Infusion of tartarines with, 395. Tincture of, 462. Compound powder of, 546. Electuary of, 593. Seville orange-peel, conserve of the yellow rind of, 112. Slavings of rust of iron, prepared, 105. Silver, preparations of, 271—274. Simple ointment, 636. Liniment, 655. Cerate, 670. Sloe, conserve of, 116. Snake-root, tincture of, 463. Soap pills, 588. Plaster, 625. Liniment, 659. Cerate, 675. Seda, 25. Vitriolated, 232. Tartarized, 241. Solidi, sublimation of, 84. Solution, in the humid and dry way, 71. Principal menstrua for, 72. Simple mercurial, 354. Mineral of arsenic, 494. Soot, tincture of, 444. Sorrel, salt of, 245. Spani/b flies, tincture of, 429. Plaster of, 615. Ointment of, 640. Cerate of, 671. Spearmint, conserve of the leaves of, 113. Essential oil of, 159. Water, 327. Spirit of, 360. Spermaceti, ointment of, 652. Cerate of, 676. Spices, aromatic, 533. Spirit of wine rectified, a menstruum for essential oils or resins of vegetables, 73. Ore extracts with, 130. On extracts with and water, 131. Spirit of sal ammoniac, 224. Ditto with quicklime, 226. Of Mindercius, 237. Camphorated of wine, 469. Compound of vitriolic ether, 485. Ditto of ammonia, 486. Succinated ditto of ammonia, 487. Volatile aromatic, &c., 486. Camphorated, 488. Spirits, distilled, 347—371. Sponge, washing of, 102. Powder, 559. Squills, drying of, 101. Conserve of, 117. Vinegar of, 399. Wine of, 417. Tincture of, 460. Syrup of, 507. Honey of, 522. Oxymel of, 525. Pills, 580. Starch, mucilage of, 388. Troches of, 561. Steel, salt of, 279. Sternumatory or cephalic powder, 574. Sticking plaster, 623. Stomachic elixir, 446. Pills, 587. Storms, purification of, 103. Pills, 589. Ointment of, 667. Strawberry water, 339. Strengthening plaster, 627. Styptic powder, 547. Sublimate corrosive of mercury, 292. Solution of it, 291. Pills of, 586. Sublimation, 84. Substances not soluble in water, preparation of, 90, &c. Suet, mutton and hog's lard, preparation of, 94. Sudorific powder, 539. Sugar, or salt of milk, 244; or salt of lead, 309. Sulphur dissolved by alkaline lixivium, 76. Preparations of, 250, &c. Precipitated of antimony, 261. Golden of antimony, 262. With quicksilver, 299. Troches of, 565. Ointment, 653. Sweet mercury, no 293. Syrup, simple or common, 508. Syrups of various sorts, 495—520.

T. Table of affinities, p. 290—294. Of the weights of some fluid measures, no 70. Of quantity of essential oil obtained from various vegetables, 195. p. 331, &c. Of quantity of opium and mercury in the different compositions of the London and Edinburgh colleges, 683. Tamarinds, infusion of, with senna, 395. Tanfry, essential oil of, 193. Tar, oil of fossile, 173. Pills, 587. Ointment, 649. Tar-water, 405. Tartrar, crystallized acid of, 203. Distilled ditto of, 204. Salt of, 209. Vitriolated, 229. Regenerated, 235. Soluble, 239. Emetic, 264. Antimonial wine of, 411. Tartarized kali, 238. Vegetable fixed alkali, 239. Natron, 240. Soda, 241. Antimony, 263. Iron, 277. Antimony, wine of, 411. Terebinthinate electuary, 599. Thebaic powder, 558. Pills, 579. Electuary, 604. Theriaca of Andromachus, 605. Tin, preparations of, 311—314. Electuary, 595. Tincture, sacred or aloetic wine, 408; or wine of ipecacuanha, 413. Tinctures of various kinds, 419—479.

Tobacco wine, no 416. Ointment of, 666. Tolu, tincture of the balsam of, 427. Syrup of ditto, 510. Tragacanth, compound powder, 548. Traumatic balsam, 428. Treacle, Venice, 605. Troche, rules for making, and various kinds of, 560—569. Troy weight, 68. Turibul mineral, 303. Turpentine, oil of, 174. Rectified ditto, 175. Tutty ointment, 654.

V. Valerian, tincture of, 464. Volatile ditto, 465. Vegetables: analogy between them and animals, 3. Pabulum of, 4. Influence of soil, climate, light, and heat upon, 5. Obnoxious to disease and death, 8. Product of, by vinous fermentation, 14, 15. By acetous fermentation, 16, 17. By putrefaction, 18, 19. By fire, 20—42. Sap of, 28. Grofs oils of, 29. Essential oils of, 31. Sebaceous matter of, 30. Nature of the colouring matter of, 43. Practical observations on, 44. Earths of, 51. Vegetable alkali, 24. Fixed vegetable alkaline salt, 211. Venice treacle, 605. Veratrum, tincture of, 466. Verdigriss, oxymel of, 523. Ointment of, 637. Vessels, glafs, naked and coated, 65, 66. Cautions with respect to the matter of other vessels, no 67. Vinegar, 17. Distilled, 200. Concentrated, 201. Of Squills, 399. Aromatic, 400. Of roses, 401. Of lead, 402. Of colchicum, 403. Syrup of, 496. Vinous fermentation, 11. Product of 14, 15. Acid of nitre, 351. Spirit of sal-ammoniac, 352. Violet, syrup of, 511. Vitriated antimony, 265. Vitriol of iron, 279. Colcotar of, 280. White, 316. Dulcified spirit of, 349. Acid elixir of, 467. Sweet ditto, 468. Vitriolated conserve of roses, 120. Kali, 228. Tartar, 229. Natron, 231. Soda, 232. Purified zinc, water of—zinc with camphor, 611. Vitriolic acid, weak, 196. Ether spirit of, 349. Acid, vinous, ib. Ether, or etherial liquor, 350. Elixir of aloes, 423. Ether, compound spirit of, 485. Water, 612. Ulcerated cancer, ointment for, 662. Volatile sal ammoniac, 223. Liquor, salt, and oil of hartshorn, 227. Elixir of guaiacum, 448. Vomica, nux, tincture of, 477.

W. Water, simple distilled, 319—347. Medicated, 606—613. Water, a principal menstruum in pharmacy, 72. Substance not soluble in preparation of, no 90, &c. Extracts with, 128. And rules for making extracts with, 129. Aerated, 205. Of kali, 212. Of pure ditto, 213. Of ammonia, 222. Of pure ammonia, 225. Of acetaed litharge, 310. Wax, oil of, 194. Plaster, 616. Ointment, 642. Weights, two kinds of, ufed, 68. Table of the weights of different fluid measures, 70. White precipitate of mercury, 298. Vitriol, 316. Lily-water, 341. Poppy, syrup of, 503. Ointment, 644. Wine, various kinds of, 13. Rectified spirit of, a menstruum for essential oils or resins of vegetables, 73. Oil of, 180. Medicated, 407—419. Camphorated spirit of, 469. Wolfbane, insipidated juice of, 125. Wood-sorrel, conserve of the leaves of, 108. Wood, decoction of, 383. Wormwood, conserve of the tops of tea, 110. Extract of, 146. Essential oil of, 181. Tincture of, 420.

Y. Yellow ointment, 648. Resin, ointment of, 650. Cerate of ditto, 674.

Z. Zedoary wine, 418. Zinc, preparations of, and copper, 314—319. Water of, vitriolated, with camphor, 611. Ointment of the calx of, 639.