zoology, the name of an insect produced in the excrescences of a species of the oak. See Coccus.

Kermes Mineral, so called from its colour, which resembles that of vegetable kermes, is one of the most important antimonial preparations, both with regard to its chemical phenomena and to its medicinal uses.

The use of kermes-mineral was not established in medicine before the beginning of this century. Some chemists, indeed, amongst others Glauber and Lemery, had before that time mentioned in their works several preparations of antimony which approach more or less to kermes; but these preparations being little known, were confounded with many others which are entirely neglected, although much praised by their authors.

The fame of kermes was occasioned by friar Simon, apothecary to the Chartreux friars. He received this preparation from a surgeon called La Ligerie, who had procured it from a German apothecary who had been a scholar of the famous Glauber. Friar Simon, from the commendations given to this new remedy by La Ligerie, administered it to a Chartreux friar, who was dangerously ill of a violent peripneumony, by which the friar was suddenly, and as it had been miraculously, cured. From that time the friar-apothecary published the virtue of his remedy. Several other remarkable cures were performed by means of kermes. The public believed in its medicinal qualities, and called it powder of Chartreux; because it was prepared only in the apothecary's shop belonging to these monks. The reputation of kermes extended itself more and more; till at length the duke of Orleans, then regent of France, procured the publication of the proceeds by La Ligerie.

This process consists in boiling, during two hours, pulverized crude antimony in the fourth part of its weight of the liquor of nitre fixed by coals, and twice its weight of pure water; at the end of this time the liquor is to be decanted and filtrated, while boiling, through brown paper. It continues clear while it is boiling hot; but when it cools, it becomes turbid, acquires a red brick colour, and again becomes clear by the deposition of a red sediment, which is the kermes. The boiling may be thrice repeated, and each time the same quantity of water is to be added to the antimony, and a fourth part less of the liquor of fixed nitre. The several sediments from these three boilings are to be added together, washed with clean water till the water acquires no taste; and the kermes is then to be dried. La Ligerie directs, that aquavit shall be once or twice poured upon it and burnt, and the kermes dried again.

We now proceed to explain the nature of kermes, and the phenomena of its preparation. Crude antimony is composed of regulus of antimony and common sulphur, united naturally with each other, as in almost all metallic minerals. The fixed alkali with which the crude antimony is boiled, although it is diluted with much water, acts upon the fulphur of the antimony, and forms with it liver of sulphur; and as this compound is a solvent of all metallic matters, it dissolves a certain quantity of the regulus of antimony. In this operation then a combination is formed of fixed alkali, of sulphur, and of regulus of antimony. Of these three substances the fixed alkali only is soluble in water, and is the intermediate substance by which the sulphur and regulus are suspended in the water. But we are to observe, that the alkali becomes impregnated by this operation, and by boiling, with a larger quantity of regulus, and especially of sulphur, than can be suspended in cold water; hence the decoction of kermes, which is clear, limpid, and colourless while boiling hot, becomes turbid and deposits a sediment while it cools. This compound, therefore, like certain salts, may be kept dissolved in larger quantity by hot than by cold water, and much of it is therefore deposited by cooling.

Further, while the kermes is precipitating, the whole Kermes, whole antimoniated liver of sulphur, which is dissolved by the boiling liquor, may be divided into two parts; one of which, that is the kermes, being overcharged with the regulus, and particularly with the sulphur, contains but a little alkali, which it draws along with it during its deposition. The other part, as it contains much more alkali, remains dissolved even in the cold liquor, by means of this larger quantity of alkali. All these propositions are to be explained and demonstrated by the following observations.

First, when the decoction of kermes is cold, and has formed all its sediment, if, without adding any thing to it, it be heated till it boil, it again entirely redissolves the kermes; the sediment disappears; the liquor becomes clear, and by cold is again rendered turbid and deposits sediment as before. Thus the kermes may be made to precipitate and to redissolve as often as we please.

Secondly, by digesting kermes in aqua regia, which dissolves its alkali and regulus, the sulphur is separated pure. The acids of aqua regia form a nitre and a febrifugal salt of Sylvius with the alkali of the kermes; and if a certain quantity of kermes be melted with black flux after having destroyed its sulphur by roasting, a true regulus of antimony may be obtained from it.

These experiments, which were made by Mr Geoffroy, and the detail of which is found in memoirs given to the Academy in the years 1734 and 1735, upon the analysis of kermes, show evidently the presence of sulphur, of fixed alkali, and of regulus of antimony, in this compound. From Mr Geoffroy's experiments we find, that 72 grains of kermes contain about 16 or 17 grains of regulus, 13 or 14 grains of alkaline salt, and 40 or 41 grains of common sulphur.

Thirdly, by repeating the boiling of the liquor upon the antimony, more and more kermes will be formed each time by cooling, as at first; and this experiment may be repeated a great many times. Mr Geoffroy says, that he repeated it 78 times without any other addition than that of pure water to supply that which was lost by evaporation; and that each time a considerable quantity of kermes was formed by cooling. This experiment proves, that the alkali transforms the antimony into kermes by overcharging itself with regulus and sulphur, and at each precipitation the kermes does not retain and take with it but a very small quantity of alkali.

Fourthly, if any acid be poured upon the liquor in which the kermes has been formed, and from which it has been entirely separated by cooling, Mr Beaumé has observed, that this liquor is again rendered turbid, and that a second sediment is formed of a yellow reddish colour, which is nothing else than golden sulphur of antimony; that is, regulus of antimony and sulphur mixed together, but in very different proportions, and with very different strengths of union, from those in which they are found in the crude antimony.

After this precipitation, in the liquor a neutral salt is left, which is formed by the contained alkali and the precipitating acid. From this experiment we find, that in the liquor from which the kermes has been deposited, a considerable quantity of antimoniated liver of sulphur remains, which differs from kermes by containing a much larger proportion of alkali; so that it can keep dissolved the regulus and sulphur with which it is united, even when the liquor is cold.

In the process for several antimonial preparations, a kermes, or compounds like it, are formed. This always happens when crude antimony is treated by fusion with a quantity of alkaline salt, so that an antimoniated liver of sulphur results from it, overcharged with regulus and sulphur; that is, containing more of these two substances than it can keep dissolved in cold water. If any of these combinations be boiled in water, a matter analogous to kermes is always deposited by cooling. This happens, for instance, to the scoria of the regulus of antimony, and in an operation described by Mr Geoffroy to abridge the process for making kermes by fusion.

To make kermes by fusion, Mr Geoffroy fuses two parts of antimony with one part of alkaline salt; he powders this matter while yet hot, and keeps it during two hours in boiling water; he then filtrates it, and receives the liquor into more boiling water, from which, when it cools, about six gros of kermes is deposited, when an ounce of antimony has been used. This method of making kermes is much more expeditious, but less perfect; for, as the author confesses, the kermes produced is not so fine and soft as that made in the ordinary method.

Mr Lemer the elder mentions also, in his Treatise concerning Antimony, an operation from which his son pretends that kermes may be obtained. This operation consists in digesting, and afterwards boiling, powdered crude antimony in a very pure liquor of fixed nitre. This liquor, if it be in sufficient quantity, is capable of dissolving quickly and entirely powdered crude antimony; and we cannot doubt but that, by cooling, a considerable quantity of a substance very analogous to kermes will be produced. Nevertheless, none of these short methods of making kermes is directed by dispensatories, or by the best books for describing the preparations of chemical remedies.

Kermes is used in medicine only; and from it singularly excellent effects may be produced, when administered by able physicians. In kermes are united the exciting and evacuating virtues of the emetic preparations of antimony, with the tonic, dividing, aperitive, and resolving properties of the liver of sulphur; that is to say, that it is capable of answering two principal indications in the treatment of many acute and chronic diseases. Properly managed, it may become an emetic, purgative, a diuretic, a sudorific, or an expectorant, as is required, and it is always attenuating and resolving. When seven or eight grains are taken at once, it chiefly acts upon the prima viae, generally as an emetic and as a purgative. A dose of three or four grains is seldom emetic, and more frequently purgative. When taken in these quantities as an evacuant, a little of it passes also into the vice secunda & tertia. When it is administered in smaller doses, it passes almost entirely into the lacteal, blood, and lymphatic vessels. In these occasions such spasms and oscillations as it does in the prima viae; so that it increases all secretions and excretions, but particularly those of urine, sweat, and expectoration, according to the dose, to the nature of the disease, and to the disposition of the patient. It produces very good effects in those diseases of the breast which proceed from fullness and obstruction.

Kermes may be administered in liniments, in oily or cordial potions, in any vehicle; or incorporated in a bolus, with other suitable remedies. One precaution, hitherto little observed, is very necessary; that is, not to join it with acid matters, if it is intended to act as kermes. Anti-acid and absorbent substances ought to be joined with it, if the patient has an acid in the prime vice, or an acetic disposition; for as these acids saturate the alkali by which the kermes is rendered an antimoniated liver of sulphur, and by which alone it differs from golden sulphur of antimony, they accordingly render the kermes entirely similar to the golden sulphur of antimony, the properties of which are very different from those of kermes.