a small negro kingdom lying between 12° and 14° North Lat. and between the meridian of Greenwich and 1° and 30° West Long. Its inhabitants, as Mr Park was informed by a variety of people in many different kingdoms, are remarkable for cruelty and ferocity; carrying their resentment to their enemies so far as never to give quarter, and even indulging themselves with banquets of human flesh. Hence the inhabitants of Bambarra, who carried on with them a long and bloody war, and must of course be well acquainted of the fact, call them *Ma dummulu*, which signifies men-eaters.

**MANURE** is so essential to agriculture, that the want of it, or an improper manner of using it, is the principal cause of the sterility of a country. We have therefore treated of manures and their action at some length in the article Agriculture in the Encyclopaedia; but as the theoretical part of that disquisition rests in a great measure on the doctrine of phlogiston, which is now exploded, it may not be improper to resume the subject here. Experience however being, after all, the only guide which the farmer can safely and confidently follow, instead of amusing our readers with theories of our own, we shall lay before them the observations of a man who seems to have united theory with practice.

"The use of manures (says M. Parmentier *) has been known in all ages, but we are yet far from having any clear and precise ideas of the nature of the juices which Paris..." which are destined for the nourishment of vegetables, and of the manner in which they are transmitted to their organs. The writers on agriculture, who have endeavoured to explain these matters, perceiving faults in most plants, were persuaded that these faults, by the help of water and heat, passed, in a saline form, through the vegetable filter. These first philosophers did not hesitate to consider every thing that has been done by the industry of man, to improve the nature of land, and its productions, as merely forming reservoirs of these salts, which they considered as the principle of fertility. This opinion was so well established among the improvers of land, that, to this day, many of them have no object in view, in their operations, but to disengage salts; and, when they attempt to explain certain phenomena which take place in their fields or orchards, they talk confidently about the nitre of the air, of rain, of snow, of dew, and fog; of the salts of the earth, of dung, of marl, of lime, of chalk, &c., and make use of those vague terms, oil, sulphur, spirit, &c., which ought henceforward to be banished from our elementary books on agriculture.

Among the authors who have attacked, and combated with most success, the opinion that the fruitfulness of soils, and the aliment of vegetables, reside in saline substances, must be reckoned Ellen and Wallerius. These philosophers examined, by every means which chemistry at that time could furnish, the various kinds of earth proper for cultivation, and also those substances which have always been considered as the most powerful manures, without being able to obtain, from any of them, any thing more than mere atoms of salt.

Animated with the same zeal, and taking advantage of the instructions found in their writings, I thought it necessary to determine, by experience, whether, as has been asserted, there really exist neutral faults in earths; and also, whether those earths are more fertile in proportion to the quantity of such faults they contain. With this view, I lixiviated, by means of distilled water, many species of cultivated earths, taken in various states, from fresh earth to that which had been impoverished by the growth of several crops; I also tried dung, reduced more or less into the state of mould; and likewise the most active manures, such as the offal of animal substances, rotted by putrefaction; but in none of these, however carefully analyzed, were found any faults in a free state. They contain indeed the materials proper for forming faults, but if they contain any ready formed, it is merely by accident.

The researches of Kraft, and those of Alston, were not attended with different results. Having lixiviated oats in ashes, not lixiviated, and in sand strongly impregnated with potash and with saltpetre, and having found that the oats did not grow, they concluded that neutral faults, and alkalies, not only retarded the growth of vegetables, but that they absolutely prevented it. It is well known that in Egypt there are districts where the earth is entirely covered with sea-salt, and these districts are quite barren. It is probably owing to this property of sea-salt, that the Romans were accustomed to scatter large quantities of it over fields where any great crime had been committed, and of which they wished to perpetuate the remembrance, by rendering the part barren for a certain time.

The idea that faults had great influence in vegetation, ought to have been greatly weakened by the following simple reflection. Supposing that faults existed in garden mould, they would be very soon dissolved by the rain, and carried away, towards the lower strata of the earth, to a depth to which the longest roots would not reach. Indeed the famous experiment of Vanhelmont would have been sufficient to have destroyed the above opinion, if it did not generally happen that we are no sooner set free from one error than we fall into another not less extraordinary. The surprising effects of vegetation brought about by the overflowing of water, and in the neighbourhood of salt marshes, and the infinite number of inhaling capillary tubes observed upon the surface of vegetables, led to an opinion that the air and water, absorbed by the roots and leaves of plants, were only vehicles loaded with saline matter, analogous to the vegetables nourished by them.

To the experiment of Vanhelmont, which was repeated by many accurate observers, succeeded those of modern philosophers; from which it clearly appeared, that plants could grow, and produce fruit, in the air of the atmosphere, and in distilled water, also in pure sand, in powdered glass, in wet mists or sponge, in the cavity of fleshy roots, &c., and that plants which had nothing but the above-mentioned fluids for their nourishment, gave, when submitted to chemical analysis, the same products as those which had undergone their process of vegetation in a soil perfectly well manured. It was also observed, that the most barren soils were rendered fertile when they were properly supplied with water by canals; and the efficacy of irrigation was repeatedly evinced in different ways: from these observations was formed the following system, that water rises in plants in the form of vapour, as in distillation; that air introduces itself into their pores; and that, if faults contribute to the fruitfulness of soils, it is only in consequence of their containing the two fluids above mentioned in great abundance.

Our author, after making many experiments upon various soils and faults, and after attending minutely to the process of vegetation, thinks himself warranted to maintain, "that saline substances have no sensible effects in promoting vegetation, except insomuch as they are of a deliquescent nature, have an earthy basis easily decomposed, and are used only in small quantity. In those circumstances they have the power of attracting, from the immense reservoir of the atmosphere, the vapours which circulate in it; these vapours they retain, along with the moisture that is produced from rain, snow, dew, fog, &c., which moisture they prevent from running together in a mass, or from being lost, either by exhaling into the air of the atmosphere, or by filtering itself through the inferior strata of the earth, and thereby leaving the roots of vegetables dry; they distribute that moisture uniformly, and transmit it, in a state of great division, to the orifices of the tubes destined to carry it into the texture of the plant, where it is afterwards to undergo the laws of assimilation. As every kind of vegetable manure possesses a viscous kind of moisture, it thereby partakes of the property of deliquescent faults. In short, the preparation of land for vegetation has no other object in view but to divide the earthy particles, to soften them, and to give them a form capable of producing the above mentioned effects. It is sufficient, therefore, that water, by its mixture with with the earth and the manure, be divided, and spread out so as to be applied only by its surface, and that it keep the root of the plant always wet, without drowning it, in order to become the essential principle of vegetation. But as plants which grow in the shade, even in the best soil, are weakly, and as the greater part of those which are made to grow in a place that is perfectly dark neither give fruit nor flowers, it cannot be denied that the influence of the sun is of great importance in vegetable economy."

Such was the opinion which our author gave of the manner in which salts act in vegetation, at a time when it was not known that air and water (which had been so long considered as elements), far from being simple substances, are capable of being decomposed by a great variety of operations both of nature and art; and nothing was wanting to complete his theory, but to know that air and water act their part in vegetation only in a state of decomposition; and that if earth well manured is a better matrix than water itself, it is because such earth has the power of converting the water into gases which are easily absorbed, and which, while their absorption takes place, communicate to the plants a motion and heat which they received when taking the form of gas, and which they lose when they enter again into combination; whence it is natural to conclude, that this motion and this heat must necessarily develop themselves in seeds, and maintain the vital action in plants.

What is a vegetable, considered chemically, according to the present state of our knowledge? It is, say the chemists, a compound of hydrogen, oxygen, and carbon, the proportions of which vary according to the agents which have concurred to its development, and according to the matrix which received and assimilated them, in order to create those combinations which are varied to infinity, by their forms and properties, and known by the generic terms of salt, oil, and mucilage. It appears, therefore, needless to seek these combinations in the different substances which are used for manure, when we wish to determine the nature of them, and explain their manner of acting in vegetation; because, supposing it true that their salts, these oils, or these mucilages, exist in their combined state, nothing but their constituent elements, namely, hydrogen, oxygen, and carbon, can possibly have any action.

The superiority of animal substances, as manures, and the remarkable luxuriance of those plants which are watered with putrid water, prove incontrovertibly, that the putrid state is favourable to vegetation, and that every substance which is liable to enter, to a certain degree, into that state, contributes very powerfully thereto. The most aerated waters are, in this case, the most beneficial. It is observed that rain, particularly in stormy weather, quickens vegetation so much, that the gardeners in the neighbourhood of Paris are often obliged to drench their plants with water taken from their wells, which, in consequence of its rawness, or its want of air, retards the vegetation of the plants; either because it precipitates the meteorised or electrified water, or because, by being mixed with the other water, it diminishes its fertilizing quality; whereas, in summer, this same well water, by being exposed to the sun for some days, acquires a smell like that of stale eggs, loses its rawness, and becomes very fit for accelerating vegeta-

tion. An atom of vegetable or animal matter is, at that time, sufficient to bring about more quickly this state of putrefaction; while these same substances, by being employed in certain proportions, far from acting as a leaven on the liquids which hold them in solution, preserve those liquids, or at least make them more slow to change.

Salts and dung, therefore, are not merely decomposed by the power of vegetation; by furnishing the results of their decomposition, they also act in the manner of leavens, the action of which is scarcely perceptible in cold or dry weather; but when they are heated by the sun, and sufficiently penetrated with moisture, they very soon enter into a sort of fermentation, suffering the various gases with which they are provided to escape. Thus manures may be considered as decomposing instruments, provided by nature, and prepared by art, to act upon water so as to bring it to a proper state of attenuation. The substances which enter into the composition of plants are, therefore, nothing but products of the decomposition of air and water, and combinations of the constituent principles of these two fluids, determined by the power which presides in the seed, and which thence has passed into the plant.

It is now easy to account for the effects of charcoal-powder, straw, &c., which are made use of to cover ground during long droughts with undoubted benefit; they are mechanical means of preventing the diffusion of moisture, and of determining it to take the form of those gaseous fluids which have such powerful effect in vegetation. As water is composed of hydrogen and oxygen, it is not surprising that, when assisted by the influence of the sun, and that of electricity, it is capable of forming, almost by itself, the solids and fluids of vegetables; taking from the atmosphere the carbon it stands in need of, to give them their most essential characters. We say their most essential characters; for those terrestrial plants which have grown in air and water do not abound in principles, and their offspring, when they have any, is by no means vigorous. We see also, that plants which are naturally of an aquatic nature, have in general but little smell, because the medium in which they live and grow furnishes only a small quantity of carbon, in proportion to the hydrogen and oxygen, which are the constituent principles of water. This is the reason why, in cold and wet years, flowers are less odoriferous, fruit less full of flavour, and more difficult to be preserved. The germ of their reproduction is weak; and they are, if the expression may be used, in a sort of droop; that is to say, they are loaded with the principles which constitute water, and even with water itself.

These observations, to which more might be added, may serve to explain why vegetation is slow and weak in a soil which is too much charged with false matter, while it is rendered quick and vigorous by a small quantity of this same matter; and why earth, which is perfectly lixiviated, and watered, from time to time, with distilled water only, is capable of giving to bitter plants their bitterness, to sweet ones their sweetness, to acid ones their acidity, to aromatic ones their spiciness, and to poisonous ones their deleterious qualities; in short, why the inherent characters of plants are more strongly marked, in proportion as the soil in which they grow is furnished with natural or mechanical means to produce duce a quantity of gas necessary to the formation of the substances on which those characters depend.

If a nitrous or marine plant can, even when growing in a soil destitute of nitre or sea-salt, occasion the production of these salts, it must be allowed that such plants would vegetate more strongly, and contain more of such salts, if they grew in soils more abounding in materials proper to form them. Thus, the different species of samphire, glasswort, sea wrack, &c. flourish on the borders of the sea, such soils being strongly impregnated with the fluids necessary to form the muriatic gas and sea salt which enter into the composition of those plants; while the sunflower, pellitory, &c. succeed best in earth which is mixed with the ruins of old buildings, in which the materials for the production of nitrous gas, and even of nitre itself, are very abundant. In short, the organization of these plants is a real laboratory for forming the aforementioned salts.

Those plants which, for their vegetation, require the most assistance from the soil and manure, are very apt to contract a disagreeable taste, if either the soil or manure are capable of supplying the principles from which it is acquired. The claus tetrahydrium, particularly all sorts of cabbages (which contain sulphur ready formed), contract a bad taste in a soil composed of mud and dung, because these substances, as they are decomposed, furnish a great quantity of hepatic gas, or of sulphurized hydrogen gas; yet plants of another claus may grow in the same soil, close by the cabbages, without partaking even in the smallest degree of the bad taste of the latter. The plants last mentioned, when growing in hepatic gas, retain only so much of it as is sufficient for the production of the substances of which they are formed; the surplus, which could not be assimilated, is thrown out by the excretory vessels, after undergoing those modifications which the digestive juices and organization of the plant, and the state of the atmosphere, have produced.

Thus we see that those plants which abound most in oily, saline, and mucilaginous principles, are generally such as require a soil well manured. Tobacco, for instance, gives forty pounds of alkaline salt or potash from every hundred weight of ashes: this plant may, by being buried in the ground, be converted into a very powerful manure; while other plants, which thrive in a middling soil, and appear as vigorous, are, in general, such as have not to great a quantity of principles in their composition, and when thrown on the dunghill, and left to rot, furnish very little manure. From such observations, it may perhaps not be impossible hereafter to judge, by the analysis of a plant, not only whether it requires a large or a small quantity of manure, but likewise what kinds of soil and manure are most fit to promote its vegetation: wild plants also may serve to show the nature of the soil which they seem most to flourish in.

Besides the physical action of manures, they have a very evident mechanical action. When mixed with earth, in a certain proportion, they not only render it more permeable to water, but the roots of plants can, with greater ease, acquire their proper size and form in it: in other cases, manures tend to unite that earth which is too loose, and, by rendering it more tenacious, they prevent the water from being lost, and the roots from becoming dry. Those manures which are called warm are suited to cold lands, not only because they render them less compact, but also because they take off a part of that moisture which such lands always have in too great quantity. Cold manures, on the other hand, by their viscid quality, give tenacity to dry and hot soils, attracting and retaining, for a longer time, the moisture which comes in their way. The nature of the soil must therefore determine what kind of manure it stands in need of, and also whether cultivating it by means of oxen or by horses is preferable; for the manures produced from these two animals have those opposite qualities which we have above described. By such observations, we shall perhaps be able to resolve a question, respecting which the sentiments of cultivators in many parts of the kingdom are much divided.

It cannot, however, be denied, that the earth is able of itself to serve as a basis and support to plants, and that it has an action more or less evident upon air, upon water, and upon dung. There is a well-known method of distinguishing clay from other earths; by merely breathing upon it, a smell is immediately perceived, sufficiently strong to show that a decomposition and fresh combination have taken place. In summer, after a drought of some days continuance, there always arises in the fields a particular smell during a shower of rain; and there is no kind of vegetable manure which, when mixed with earth, does not send forth a smell. This proves, that the nature of the soil must have an influence, not only upon air and upon water, but also upon the effect of manures; and that before we speak of their power, we should always specify what kind of earth they were applied to; because when manures and earth are mixed together, there ensues an action and reaction more or less favourable to vegetation.

Having examined to what degree air and water enter, in substance, into the vessels of plants, and having shown that the principal action of earth, of salts, and of manures, consists in preparing, elaborating, and decomposing these two fluids, and in giving to the products of their decomposition the forms they require, to accomplish the purpose of nature in vegetation, our author makes some observations upon the particular effects of certain substances used for improving land, such as marl, lime, chalk, and wood ashes; which are usually applied either to an exhausted soil, in order to restore it, or to a drooping plant, with a view to give it strength. Of the efficacy of these substances no one doubts, but it does not appear that we are equally agreed respecting their manner of acting.

Marl (a manure whose effects are well known, and which is found to be of the greatest benefit in those districts where it can be procured in sufficient quantity) is capable of acting in the same manner as the most fertile soil, when the principles of which it is composed, namely, clay, sand, calcareous earth, and magnesian earth, are justly proportioned to each other. But it is sometimes compact and tenacious, because it contains a superabundant portion of clay, and at other times porous and friable, because it contains too much sand, and therefore is not in general fit for vegetation by itself. These considerations ought always to be our guide when we mean to employ marl as a manure.

It has been supposed that to marl was a sort of technical expression, intended to denote the bringing tog... ther or dividing the earthy particles by means of clay or sand. It appears to our author, that neither of the above operations can properly be called marling; because, in either case, all we do is, to put the soil into a situation to receive and to profit by the influence of the atmosphere, and that of the manures made use of. The peculiar principle of marl is, that part of it which, like lime, acts very powerfully upon the different aeriform fluids, is easily reduced to powder, effervesces with acids, and sends forth a quantity of air-bubbles when water is poured upon it. Now this matter, which in a particular manner does the office of manure, resides neither in clay nor in sand. Upon the proportion of it depends the duration of the fertility it produces; consequently it is of importance, when we make use of marl, to know which of its constituent parts it contains in the greatest proportion, otherwise in some cases we should only add one common kind of earth to another. Hence our author infers, that for a chalky soil clay is the proper manure, and that in such a soil a clay bottom is of more value than a gold mine.

"Wood-ashes, as a manure, may be, in some respects, compared to marl; at least they contain the same earths as those which generally enter into the composition of marl, but they contain a greater quantity of saline substances, proceeding from the vegetables of which they are the residue, and from the process made use of in their combustion; a process which increases their activity, and should render us careful in what manner and for what purposes we employ them. Wood ashes, when scattered over fields, at proper times and in proper quantities, destroy weeds, and encourage the vegetation of good plants. But do the ashes produce this effect by a sort of corrosive power? I cannot (says our author) think it; for in that case all kinds of plants would indiscriminately be acted upon by them, and to a certain degree destroyed.

Besides, the ashes of fresh wood are seldom employed until they have been lixiviated, in which state they are deprived of their caustic principle; those ashes which are most commonly made use of for manure are produced either from wood that has been floated in water, or from turf, or from pit-coal, and contain little or no alkaline salt.

It appears much more probable that ashes, when laid upon ground, destroy the weeds by a well-known effect, namely, by seizing with eagerness that moisture which served to produce those weeds, and which in a superabundant quantity is necessary to their existence and support. Whereas those plants which have a firmer texture and a longer root, which are rendered strong by age and by having withstood the rigour of winter, and which are in fact the plants of which the fields are composted, do not suffer any damage from the application of the ashes; but, on the contrary, by being freed from the superfluous weeds which stifled them, and robbed them of a part of their sustenance, they receive a quantity of nourishment proportioned to their wants. The state of relaxation and languor to which they were reduced by a superabundance of water, leaves them, the soil gets its proper consistence, and the grass, corn, &c., acquiring the strength and vigour which is natural to them, soon overcome the mols, rushes, and other weeds; thus a good crop, of whatever the field consists of, is produced. It is in the above manner that wood ashes act, whenever in the spring it is necessary to apply them to meadows, corn fields, &c., the plants of which are stifled and weakened by a luxuriant vegetation of weeds, the usual consequence of mild and wet winters.

When wood ashes produce an effect different from what is above described, it is either because they happen to contain too much alkaline salt, or that they are laid on the ground in too great quantity, or that the fields to which they are applied were not sufficiently wet to restrain their action; for when they are scattered upon cold soils, and buried by the plough before the time of sowing, they are, like lime, of great service. The last-mentioned substance is very efficacious in other circumstances; and there is a well-known method of using it, practised by the Germans, as follows: A heap of lime is formed by the side of a heap of poor earth, and water is poured upon the lime; the earth is then thrown over it, and becomes impregnated with the vapours which escape from the lime while it is flaked. The earth, after being thus aerated, may be separated; and although no lime remains mixed with it, is, by the operation just described, rendered capable of giving a luxuriant vegetation to whatever plants may be put into it.

It is possible, therefore, to aerate earth as well as fluids; for this purpose, by mixing it with certain substances, during their decomposition, we must attach to it the principles of which those substances are composed; from which there results a matter so loaded with gas, as to form a more compound substance, and one which has acquired new properties. The Arabs, for example, who take great pains to improve their land, are accustomed to make large pits, which they fill with animals which happen to die; these pits they afterwards cover with calcareous or clayey earth; and after some time these earths, which of themselves are sterile, acquire the properties of the richest manures.

The foregoing observations may at least be considered as proving, that those substances which, when employed fresh and in too great quantity, are most prejudicial to vegetation, have, on the contrary, an advantageous effect, when they are previously made to undergo a fermentation; or when they are mixed with earth or water, in a proportion adapted to the end proposed. The grass of fields in which cattle or poultry go to feed, after the first or second crop of hay, appears to be dried by the urine and dung of those animals; as if fire had been applied to it; whereas these same excrementitious substances, when combined with earth, or diluted with water, are capable, without any other preparation, of performing the office of good manure.

But if animal excretions, when applied in substance to plants, were capable of acting upon them, as is affirmed, in such a way as to corrode or burn them, how could feed which has been swallowed, and escaped the action of the digestive powers, be prolific when thrown out by the animal, after having remained so long in its dung? yet we often see oats, so circumstanced, grow and produce seed. Is it not more consistent with experience and observation to suppose, that these excrementitious substances, being filled endowed with animal heat, and with an organic motion, diffuse round plants in vegetation a deleterious principle or inflammable gas, which destroys them; for soon after their application, the foliage of the plant grows yellow, dries up, and the plant withers, unless there happens a shower of rain which which revives it. When these substances are diluted, by being mixed with water and earth, they lose that principle which is so destructive to vegetable life, and an incipient fermentation augments their power as a manure, so that they may be immediately made use of without any apprehension of injury from their effects.

"It appears, therefore, that any operation upon excrementitious substances, by which they are dried and reduced to powder, cannot be practised without depriving those substances of a great part of such of their principles as are easily evaporated, and upon which their fluidity depends; these principles, when diluted with water, and confined by being mixed with earth, are capable of increasing the produce of the soil. Such is the way in which the husbandmen in Flanders make use of this kind of manure, in the cultivation of a kind of rape or cole seed, which is to them a very important branch of agricultural industry and commerce; and they never observe that the sap carries up any of those principles which give such manure its offensive smell; nor do they observe, that the fodder produced from fields so manured, whether eaten fresh or dry, is disagreeable to their cattle. The excrements of all animals would be injurious to plants, if applied too fresh, or in too great quantity; and a gardener could not commit a greater fault, than to put more than a certain quantity of them into the water he means to make use of to water his young plants; in short, this kind of manure is to be used in a very sparing manner; and he that is too prodigal of it will find, to his cost, that excess, even of that which is otherwise beneficial, becomes an evil.

"It must certainly be allowed, that excrementitious substances are a very advantageous manure for cold soils, and suited to most vegetable productions; a long experience of their effects over a large tract of country, and the acknowledged intelligence of the Flemish farmers, ought to be considered as sufficient to overcome the prejudice that has been raised against this sort of manure. Supposing that the bad effects which have been attributed to it, when used in the state in which it is taken out of privies, &c., are not the offspring of a prejudiced imagination, they may have arisen from its having been made use of at an improper time, or in too great quantity; or from its having been applied to a soil and for the cultivation of plants to which it was not adapted; for we know that the excess of any kind of manure changes the smell and taste of plants, and the same effect is produced by watering them too frequently. Striking examples of this change are seen in the strawberry and in the violet, when such as have grown in the woods are compared to those produced from some of our over-manured gardens; also in the lettuce, and some other plants, when those raised for sale by the gardeners about Paris are compared to those of some particular kitchen gardens. In the markets of some cities, the carrots, turnips, and potatoes of the fields, are preferred to the same kind of roots cultivated by the gardeners (a); for though the last are of a larger size, they have not so good a flavour. Some vegetables, therefore, are like certain wild species of the animal kingdom; they resist every kind of culture, as Manure, those animals resist every effort to tame them.

"Although experience has taught the Flemish farmers, that excrementitious substances are more active in their natural state than when dried, yet it cannot be denied that drying them, and reducing them into powder, is sometimes very advantageous, because in that state they are much less offensive, are easily transported to any distance, and may be used when most convenient or most proper. In many cities the inhabitants pay to have their privies emptied; in other places, those who empty them pay for their contents; and it would astonish any one to be told how great a revenue is produced in the city of Lille in Flanders by the sale of this kind of manure. I am, however (says our author), far from thinking that it is right, in all cases, to employ it in the above mentioned state of concentration; it would be better, in my opinion, to follow the example of the Flemish farmers, who use it the first year for the cultivation of plants for oil, or for hemp or flax; and the second year for the best kinds of grain; thus obtaining two crops, instead of one, without any farther preparation of the land. What is said above may be applied also to the manures produced from the dung of cattle, poultry, &c. (particularly to pigeons dung, the most powerful manure of its kind), all which, by being dried and powdered before they are used, lose a great portion of their activity. From these observations another fact may be deduced, namely, that manure should not be taken from the place where it has been thrown together until the season of the year and the state of the land are such that it may be put into the ground as soon as it is brought to it. In some districts a very injurious custom prevails of carrying the manure into the fields, and leaving it there formed into small heaps, exposed for some days to the elements; during which time, either the sun and wind dry up its natural moisture, leaving a mass which is much less active; or the rain dissolves and carries away the extractive part impregnated with the salt. This kind of brine, which is the most powerful part of the manure, penetrates the earth to a considerable depth, and thaws (by the thick tufts which arise in those places, and which produce more straw than grain) that manure ought to be put into the ground as soon as it is brought to it, because it then possesses its full force and effect, and consequently would be then used to the greatest advantage.

"We have always at hand the means of composting, from a great variety of vegetable and animal substances, such manures as, when brought into a proper state, and mixed with land, contribute to its fertility. Chemistry also offers us a number of substances, which, although when used separately they tend to diminish the fertilizing quality of the earth, are yet capable, by being combined, of forming excellent manures; such, for instance, is that saponaceous combination which is produced from a mixture of potash, oil, and earth. What an advantage it would be, if, instead of being sparing of manure, the inhabitants of the country would endeavour to increase the number of these resources, and to render them more beneficial, by employing them in a

(a) We believe they are universally preferable. more effectual manner. How many years had passed before it was known that the refuse of apples and pears, after they are pressed (and which used to be thrown away as useless), is capable of forming as valuable a manure, in cider and perry countries, as the refuse of grapes does in wine countries.

From what has been observed, our author concludes, that manures act, in many circumstances, like medicines, and consequently that the same sort of manure cannot be adapted to every situation, and every kind of soil; we must therefore take care to make proper distinctions between them. Whoever shall pretend that any particular kind of manure may be used, with equal benefit, in grass land, corn-fields, vineyards, orchards, kitchen gardens, &c. ought to be classified amongst those quacks who undertake to cure all persons with the same remedy, without any regard to their age, constitution, &c. It is probably from not having paid sufficient attention to the aforementioned distinctions, that some authors have found fault with particular manures, while others have spoken too highly in their favour. He thinks, however, and we agree with him, that we are still in want of a course of comparative experiments upon the various kinds of manures, considered according to their influence with respect to different soils, situations, and productions. If this part of rural economy were better understood, we should perhaps see many places in a state of cultivation, which, on account of the bad quality of their soil, have hitherto resisted all our endeavours to render them fertile.

Perhaps it would not be proper to dismiss this subject without noticing Mr Middleton's observations on various kinds of manure, which were published in the Transactions of the Society of Arts for the year 1799. This gentleman agrees with Mr Parmentier in recommending the excrimentitious matter of privies as the most powerful of all manures on some kinds of soil; but he differs from him, and we believe from most writers on agriculture, when he affirms, that wood ash, when spread on the grass in February or March, are of very little service, and that the ashes of coal and even of peat are of none upon any kind of land. He likewise affirms foot to be of very little value as a manure, fagackers waffle to be of none, or rather to be hurtful; and he seems to consider malt-dry, including the dust from the malt-kilns, to be, after the foil of privies, one of the most powerful manures. He affirms, from his own experience, that, with respect to fertilizing power, the foil of privies, compared with farm-yard dung, is in the proportion of five to one.