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Caird. It must, therefore, be the interest of all persons connected with agriculture, and especially of the owners of such land, to encourage the extension of this improved system, and by every means to diffuse the knowledge on which the profitable practice of the system depends.

placed at the head of this article, afford us the materials for a satisfactory reply.

Our readers are aware that botany, physiology, geology, meteorology, and mechanics, all lay claim, and with much justice, to the honor of having greatly benefited general husbandry and those conBut more than this must be done. For the com- cerned in it. But during the last twenty years fort and fair encouragement of all parties we must Chemistry has taken the lead in explaining the not stop here. If prices are to be permanently processes and illustrating the principles on which lowered, both for corn and cattle, it may be feared the practice of agriculture depends. During this that improvements which were profitable under the period its materials have been gradually accumuold prices will not be so under the new. And, lating; and, when collected, systematized, and further, if the Lothians and Lincolnshire, and the applied, as in the writings of Liebig, Boussingault, best parts of all our other counties be already highly Johnston, and others, they form the wide and imfarmed, Mr. Caird's substitute for protection will portant branch called agricultural chemistry. Our not avail them. They not only cultivate well limits make it impossible for us to illustrate and already, but they pay rents in proportion; and, compare the claims of all the sciences we have unless there is some way for them to advance fur-named. We shall, therefore, now confine ourselves ther still, both the rents of the owners and the profits of the cultivators of our most important districts must certainly fall. It is not, therefore, to high farming, in the abstract sense, that we can look for the general and permanent support of our In a former article in this journal we drew national agriculture. It is only by the general attention to the systematic works upon agricultural introduction of improvements upon existing meth-chemistry which up to that time had been pubods, on rich land as well as on poor, on the high-lished-those of Lord Dundonald, Davy, de Sausfarmed as well as on the low-farmed, that the actual sure, Sprengel, Liebig, (the great author and guide condition of all who depend on land is to be bettered, or indeed maintained. We must raise more corn and cattle on the same surface, or we must raise the same quantities at a less cost.

And how is either of these things to be done? As in all the other arts by which this country has attained to eminence, it must be by the application of more skill. If the United States of America are now beating us out of any of our old markets, it is not that they possess more energy than we do, more industry, or more intelligence, or have cheaper labor; but because, from their earnest competition, they have in these cases been more attentive to avail themselves of the daily discoveries of science, and have accordingly so far succeeded in producing better or cheaper articles.

to the more palpable benefits which chemistry has already bestowed upon the agriculturist, and which it is to be presumed are but samples of what it may have still in store for him.

of the movement still in progress,) Johnston, and Boussingault-and we gave a general sketch of the then known relations of this science to the various branches of rural practice. The chemical works we have placed at the head of the present article are such as have appeared since that time; and it is to some of the new matter contained in them that we now propose to address ourselves.

The "Contributions to Scientific Agriculture," being the most recent of these publications, comprises, as the introduction to the work informs us, a portion of the results of the researches which have been carried on in the laboratory of the author during the last five or six years; and a rapid glance over its table of contents will show us how widely chemistry enters into the various

It is from the aids of science, hitherto so much departments of rural life. It performs a part, undervalued, that British agriculture is to draw new strength. If other nations have outstripped her in any art, she, by the use of the same means, may surely outstrip her present self. She has only to carry out a little more zealously and generously into agriculture the system by which her other manufacturing arts have been raised to their present height; and the numerous cases of individual distress which all fiscal and social changes involve—and which, we may add, all great national triumphs bring along with them—will be swallowed up and disappear beneath the swelling tide of general prosperity.

But what has science yet done for practical agriculture to justify this opinion concerning its future use? This is a question which is still asked, notwithstanding all that has not only been written but performed of late years, showing the relations of science to practical husbandry in its largest sense. The works, of which the titles are

indeed, in almost every process-throws light upon every appearance-explains the qualities and uses of all the materials which the husbandman works with or produces, and aims at removing the greater part of the difficulties which lie in his way. The culture of the land, the manuring of the crops, their value when reaped, the feeding and treatment of stock, the manufacture and management of butter and cheese, have all been made the subjects of analytical investigation in the laboratory; and the practical applications of the results of numerous investigations of this kind are presented to us in the pages now before us.

It is not our intention to advert to any of the subjects of purely theoretical interest which are discussed in these pages. But we propose to select, under the several branches of agriculture, one or two points of a positive and material kind, such as will illustrate the money value of science to practical agriculture.

The true and extensive money value of science | indicated and measured. It must be of importo general husbandry is neither understood nor tance, therefore, to know how much of these comacknowledged. When, eight or nine years ago, pounds, or, in other words, how much nitrogen, the popular and most valuable work of Liebig different vegetable productions usually contain— drew the attention of practical men to the relations how far the usual proportion is subject to variaof chemistry to agriculture, their minds became tion-upon what circumstances such variation desuddenly filled with obscure and undefined expec-pends-and how far it is within the reach of human tations of some great, visible, and immediate good control. Such questions have obviously an intithey were to derive from this relationship. Ev-mate relation to the actual money value of food in ery man's visions were shaped according to his the rearing and nourishment of animals; and a own knowledge and wants; but they were all few illustrations will show how chemistry has equally vague. When a certain number of years recently occupied itself in solving them. had passed, and extravagant hopes had not been realized, a violent reaction set in; and, as is usual in such cases, we were told that nothing had been done. Yet all the while a great deal had really been done, and was doing. Analytical researches were gradually shedding light upon practical operations in every direction; and it is the immediate pecuniary profit, consequent on some of these researches, which we are now desirous of making intelligible to our readers.

First. The proportion of nitrogen* contained in different kinds of vegetable food, is a question which is connected with numerous and various economical considerations. This will appear by a statement of the opinion at present entertained concerning the relation of nitrogen to the sustenance of animal life.

Among the parts of the living animal, the muscles occupy an important place, not merely in bulk, but in reference also to the health and strength of the body. The muscles contain nitrogen; and, besides a little fat, are mainly composed of a substance, to which, because of its stringy or fibrous nature, chemists give the name of fibrin. Now this fibrin is almost identical, in chemical characters and composition, with the white of eggs, (albumen,) with the curd of milk, (casein,) with the glutenf of wheat, and with certain similar substances which exist in beans, peas, barley, oats, potatoes, turnips, cabbage, and, in fact, in almost every vegetable esculent, in greater or less proportion. All these substances contain nearly the same per centage of nitrogen, and are distinguished by the general name of protein compounds.

It is now ascertained that, when vegetable food is introduced into the stomach, the gluten, albumen, &c., which it contains, is dissolved and extracted from it, conveyed from the stomach into the blood, and by the circulating blood carried to those parts of the body in which, owing to the natural waste, or to the demands of animal growth, the muscles require to be renewed or enlarged. The power of a vegetable substance, therefore, to increase or sustain the muscles of an animal, depends materially on the quantity of these protein compounds it contains-or on the quantity of nitrogen by which that of the protein compounds is * Nitrogen is a kind of air which forms about four fifths of the bulk of our atmosphere.

It is the object of chemical research not merely to explain known facts, but to remove misapprehensions and correct erroneous opinions. The recent determinations of the proportion of nitrogen contained in wheat have served both these purposes. Thus it was long asserted and believed, that the wheat of warm climates always contained more nitrogen, and was consequently more nutritive and of higher money value, than the wheat of our more temperate countries. But later researches have corrected this hasty deduction, and have placed our home wheat in its proper position, economical and nutritive, as compared with the wheat of India, of Southern Australia, or of the Black Sea.

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Again the British miller usually requires a portion of foreign wheat to mingle with our native grain, both to make it grind more easily, and to satisfy the baker with a flour which will stand much water. The pastry-cook, and the macaroni maker, also demand of him a flour which will make a peculiarly adhesive dough. These several qualities were supposed to be inherent only in wheat which abounded, in an uncommon degree, in gluten, and which was produced under specially favorable conditions of soil and climate. Modern chemistry has the merit of gradually removing these misapprehensions, and of directing us to the true causes of all such differences.

So in regard to the superior amount of muscleforming matter supposed to exist in wheat in comparison with other kinds of native grain, such as the oat. Experience had long taught the Scotch that oats, such as they grow in their climate, are a most nutritious food; but the habits of the more influential English, and the ridicule of a prejudiced lexicographer, were beginning to make them ashamed of their national diet. Chemistry has here stepped in; and, by her analysis of both, has proved not only that the oat is richer in muscle-forming matter than the grain of wheat, but that oatmeal is, in all respects, a better form of nourishment than the finest wheaten flour.

But what is more, chemistry has brought us acquainted with the value of parts of the grain formerly considered almost as waste. The husk or bran of wheat, for example, though given at times to pigs, to millers' horses, and other cattle, virtue in itself. Analysis, however, has shown was usually thought to possess but little nutritive it to be actually richer in muscular matter than the white interior of the grain. Thus the cause

+ When wheaten flour is made into dough, and this dough is washed with water upon a sieve as long as the water is rendered milky, an adhesive sticky mass remains on the sieve, to which chemists give the name of gluten. of its answering so well as food for cattle is

explained; and it is shown that its use in bread gorse grows up an unheeded weed, and luxuriates (whole-meal bread) must be no less nutritive than in favorable spots without being applied to any useeconomical. ful purpose. In other districts, however, it is

The true value of other kinds of food is also established by these inquiries. Cabbage is a crop which, up to the present time, has not been a general favorite in this country, either in the stall or for the table, except during early spring or summer. In North Germany and Scandinavia, however, it appears to have been long esteemed; and various modes of storing it for winter use have been very generally practised. But the cabbage is one of the plants which has been chemically examined, in consequence of the failure of the potato, with the view of introducing it into general use; and the result of the examination is both interesting and unexpected. When dried so as to bring it into a state in which it can be compared with our other kinds of food, (wheat, oats, beans, &c.,) it is found to be richer in muscular matter than any other crop we grow. Wheat contains only about 12 per cent., and beans 25 per cent.; but dried cabbage contains from 30 to 40 per cent. of the so-called protein compounds. According to our present views, therefore, it is preeminently nourishing. Hence, if it can but be made generally agreeable to the palate, and easy of digestion, it is likely to prove the best and easiest cultivated substitute for the potato; and no doubt the Irish kolcannon (cabbage and potatoes beat together) derives part of its reputation from the great muscle-sustaining power of the cabbage-a property in which the potato is most deficient.

Further, it is of interest-of national importance, we may say that an acre of ordinary land will, according to the above result, produce a greater weight of this special kind of nourishment in the form of cabbage than in the form of any other crop. Thus, twenty tons of cabbage-and good land will produce, in good hands, forty tons of drum-head cabbage on an imperial acre-contain fifteen hundred pounds of muscular matter; while twenty-five bushels of beans contain only four hundred pounds; as many of wheat only two hundred, twelve tons of potatoes only five hundred and fifty, and even thirty tons of turnips only a thousand pounds. The preference which some farmers have long given to this crop, as food for their stock and their milch-cows, is accounted for by these facts; while, of course, they powerfully recommend its more general cultivation as food for man.

already an object of valuable though easy culture, and large breadths of it are grown for the feeding of stock, and yield profitable returns. Chemical researches show its nutritive property to be very great. Of muscle-building materials it contains when dry as much as thirty per cent., and is therefore in this respect superior to beans, and inferior only to the cabbage. Under these circumstances we can no longer doubt the conclusions at which some experimental feeders had previously arrived, nor the advantage which might be obtained from the more extensive cultivation of gorse on many poor and hitherto almost neglected soils.

The history of the Tussac grass is familiar to most persons. A native of the Falkland Islands, where it grows in the large tufts or tussacs from which it derives its name, it is described as fattening in an extraordinary manner the stock, and especially the horses, which graze upon it. Some of the seeds which have been lately imported into this country having vegetated, the grown-up plants have been analyzed; and it was found that the proportion of muscle-forming ingredients in the dried grass is as great as in the best samples of wheat, oats, or barley, and therefore that the grass is of a very nutritious character." Thus its alleged feeding qualities are confirmed; and we may look forward to seeing it, on further trial, domesticated in Great Britain.

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The money value of the above investigations is obvious enough-and we do not dwell upon them. But the same branch of chemical inquiry deals with questions of a larger and higher kind. We shall quote one or two illustrations of this from the materials before us.

Among the articles imported in great quantity into this country are the oily seeds of flax, rape, mustard, &c., for the use of the oil-crusher-and the refuse or cake from foreign oil-mills, for the feeding of cattle. The importance of this cake, whether of home or of foreign manufacture, either as a manure, or as food for cattle, is now well known. But chemical analysis has shown that its efficiency is owing to the large proportion of muscular matter it contains, in addition to the oil which still remains in it. It has further shown that all oily seeds, almost without exception, are equally rich in this kind of matter; and thus a common value has been given to the refuse-cake of whatever We may add, while speaking of cabbage, that it seeds and nut-kernels are crushed for oil. The is known to be so exhausting to many soils, that experience of practical farmers would long have wheat will scarcely grow after an abundant crop of wandered in uncertainty, and have often battled it. It springs up indeed, but yields little straw, with prejudice in vain, before it could have satisfied and early runs to a puny ear, containing little the agricultural body at large of the truth of what grain. But the same analysis, which shows the this analysis has at once conclusively and directly value of the cabbage crop, shows also what it takes proved. In the mean time some of these cakes had from the soil; and explains therefore the kind of almost disappeared, by name at least, from the exhaustion produced by it, by what special appli- market. Poppy-seed cake was suspected of sopocations this exhaustion is to be repaired, and how rific qualities. Accordingly, in this country it had repaired at the least cost. till lately sold at a very low price—about one half Again-In many parts of our island furze or the price of foreign linseed cake, and indeed was

chiefly used as a manure. But this delusion is now | injury to the quality of the flour; and in its natudispelled; and the difficulty of procuring it in our home markets is accounted for by its being mixed up with other cakes, and sold under another name. New oil-cakes, too, have come into demand; and the same analyses which show their value as food, show also their value as manures. Hence the refuse of seeds, which for special reasons cannot be used for food, have found a ready sale among the traffickers in manures. Those of the castor-oil bean, of the purging nut, (Jatropha purgans,) and even of the Croton tiglium, which yield the acrid croton oil, have obtained access to our markets; and form at once new articles of import and of traffic with other countries, and new means of improvement to our island husbandry. We save, also, for the use of man, what has hitherto been wasted as worthless.

ral state it may be used with advantage in feeding cattle and poultry." This answer, accordingly, assigns the Darra its distinct place as a commercial article; and thousands will be benefited by it, to whom the term chemistry is scarcely known, and to whom it would be almost impossible to convey an idea of the meaning of a chemical analysis. The same is the case in regard to Guinea corn-which is grown extensively in Barbadoes and in other of our West India islands—and to the sweet quinoa, the native food of Peru and Western Mexico. Their nutritive quality has been determined from samples imported for trial, their degree of adaption to our market pointed out, and their true economical and commercial value indicated.

With respect to the plantain, the native food of another large portion of the earth, especially of the islands and shores of the Carribean Sea and of the Gulf of Mexico, a still more interesting question has been raised. In Dutch Guiana, which

Other consequences have followed. The best cakes being high in price, and their composition being known by analysis, it was asked-cannot an artificial substitute be manufactured, equally good as food, and of less money cost? Cannot the sev-lies on the north-east corner of South America, it eral materials for forming muscle and fat be sepa- formed almost the entire subsistence of the field rately procured at a lower price, and put together negroes. But in this colony it was ascertained by into another compound, at a cheaper rate than is statistical returns that the slave population was paid for the costly oil-cake? A paper in the " Con- diminishing at the rate of nearly two per cent. tributions" contains several recipes for compound- (1·77) per annum; and this rapid decrease was ing such artificial cakes; and manufactories for by some ascribed to the food on which they lived. their preparation have already been established, in Its nourishing qualities were suspected. The probconsequence, in various quarters. In this manner lem could be adequately solved by chemical analychemical inquiries are constantly giving birth to sis only; and the indications of these analyses new arts; by means of which not only are new are thus expressed :-" In the tropical climate of productions brought into the market, but old ones, Guiana, there is no reason to believe that the with which they come into competition, are cheap- plaintain, eaten in the quantity in which the ened to the buyer. slaves of Guiana consume it, is deficient in any Chemistry is obviously in close alliance with degree in necessary nourishment, where the ordicommerce. Every one is familiar with the em- nary exertion of which a man is capable in such ployment of caoutchouc, with the innumerable climates is alone required." But if the amount uses lately found for vulcanized India rubber and of labor exacted be equal to that performed by an for gutta percha, and with the large importations able-bodied willing laborer in Europe, the amount of both which in consequence have taken place. of sustaining food given to the slave ought to be so The trade in articles of human food is equally in- also. However true it may be, therefore, that in debted to chemical science. Egypt has long fur- ordinary circumstances, and when only submitted nished corn to Europe, and Egyptian beans are a to ordinary fatigue, the kind and quantity of food staple article in our markets. But Egypt, Tur- given to the negroes of Surinam may be sufficient key, and India raise largely a kind of grain which to sustain their health and strength, yet if, by in this country is comparatively little known.-means of the lash or any other extraordinary stimThe Darra, Durra, or Dhoora, is a very prolific plant, yielding a small seed, from which a perfectly white flour is prepared, and from which the inhabitants of the Upper Nile make a native beer. A quantity of the seed, lately brought into this country, could find no sale, till chemistry had replied to the questions-what is its nutritive quality? what grain does it most resemble? for which of our common kinds of food may it be substituted, and in what proportion?—since, on the answers to these inquiries depended the price which should be paid for it. The answer is, that "it has a nutritive quality about equal to that of the average of our samples of wheaten flour; is void of sensible color, taste, or smell, and may therefore be ground up with wheat without any

ulus, they are made to perform more than an equivalent amount of labor, the plantain food given them may prove insufficient, and the population may diminish in a certain sensible ratio from this cause alone."-Contributions, p. 154. Thus the dilemma was shown to be only shifted. If the planter was relieved from the responsibility of this mortality in one form, it was to charge him with it in another. The food of the negro had become deficient, in consequence of the excess of labor exacted from him.

We may advert for a moment, before quitting this part of our subject, to a domestic question, which has been sometimes made a political one. When it is looked at from a more reasonable point of view, it will be seen that one of the main ele

ments for deciding it must be derived from chem- that the absolute and comparative worth-the real istry. The use of Malt in feeding cattle has recently occupied much of the public attention, and the profit of malting barley, before giving it to stock, has been very much extolled. Now, it has been ascertained by chemico-physiological inquiries that a substance, when introduced into the stomach of an animal, may perform one or both of two functions. It may contribute directly, and in proportion to its weight, to the sustenance of the animal, or it may assist the solution, digestion, and consequent usefulness of other food consumed along with it.

money value of the products of these manufactories-can be tested and ascertained. On points so universally acknowledged, therefore, we need not dwell-though the merits of chemistry in reference to them alone ought to have secured to it a much higher consideration with the agricultural community, than has yet been conceded to it, for all the benefits it has conferred upon them. We will take an illustration rather from a subject in which chemistry and geology have played into each other's hands, and have entitled themselves, though in unequal shares, to the gratitude of the farmer. In so far as the first or direct feeding quality is Descriptive geology had recorded that in the deconcerned, it appears that barley is clearly more posits of what is called The Crag-and in those valuable than the quantity of malt it yields; inas- of the Greensand, which in our southern counties much as this grain loses from ten to twelve per skirt the chalk on its southern and eastern borcent. of its weight during the process of malting, ders-calcareous-looking nodules of various sizes, of which loss six or seven per cent. consist of sub- often including shells or corals, were not uufrestances of a highly nutritive kind. Thus far the quently met with. Chemistry applied its tests to laboratory is favorable to the minister who seeks these nodules; and as a matter of interest recorded to retain the duty on malt. On the other hand, that they consisted in large proportion-somehowever, it is equally certain that malt possesses times to the extent of sixty per cent.-of phosa remarkable power of aiding the solution of veg-phate of lime, derived, no doubt, from the remains etable food in the stomach, and consequently of of animals which had been entombed in these facilitating digestion. Food mixed with it, there- ancient beds of rock.* fore, goes further-from the digestive organs be- But by and by, as the composition of plants being enabled to extract more perfectly whatever came better known, chemistry said "Inasmuch can contribute to the sustenance of the body. as phosphate of lime being always present in, must Malt owes this property to a substance which is be indispensable to, the growth of plants; and, inproduced in it in small quantity during the process asmuch as bones seem to owe a part of their effiof sprouting-the first step in the manufacture of cacy, when applied to the land, to the large promalt. In this particular, therefore, chemistry portion of this phosphate which they contain and makes out the superiority of malt to barley, and yield to the roots of plants, it is probable that the supports the practical feeder in recommending it mineral phosphate such as is found in these nodas a food for stock. But this case, as most others, ules, if brought near the roots in an available is one of proportion. The solvent power of good form, might produce a similar fertilizing effect." malt is found to be so great, that one tenth of it Sprengel was the first, we believe, to whom this mixed with other dry food, or one twentieth with idea occurred. He made the first experiment with moist food, like potatoes, is sufficient to produce the mineral phosphate, which is now known to the chemical effect on which its usefulness in the mineralogists by the name of Apatite; and, as he process of digestion depends. Hence the stock states, with considerable success. But the scarcfarmer who was free to do with his grain as he ity of the substance at the time prevented it from pleased would malt only this one tenth of his bar-being of any real advantage to the farmer as a ley-supposing him to be about to consume all his own barley, and to feed with that grain aloneand would thus incur only one tenth of that loss of weight or substance which, as we have seen, barley undergoes during its conversion into malt. How far the duty on malt interferes with the general market of the barley-grower, or whether it would be worth his while to agitate, for the sake of the duty now payable on the trifling proportion of the grain which he would retain in the shape of malt to feed his cattle with, are questions which chemistry, of course, does not pretend to determine.

manure.

It is only within these few years that it has been discovered that the nodules, of which we have spoken as occurring in the Crag, were to be met with in some places in sufficient quantity to allow of their being dug up at a cheap rate and it is little more than two years since they were first found in the Greensand in such quantity as to promise to be of use. But the trials which have been recently made with these nodules (after being crushed and dissolved by means of sulphuric acid, as is now

When phosphorus is burned in the air, it gives off Secondly. Let us now briefly turn to the sub-white fumes, which are called by chemists phosphoric acid. The white smoke which rises from a lucifer match, ject of Manures. As regards guanos and similar when first kindled, is due to the burning of phosphorus, substances, the services of analytical chemistry and consists of this phosphoric acid. When united to lime, this acid forms phosphate of lime. Bones, when to agriculture are at present pretty well under- burned, leave a bulky white ash, weighing about half as stood. It is this branch of science which has estab- much as the original bone. This bone-earth consists lished numerous manufactories of artificial ma- ly in the bodies of animals possessed of bones. It is found chiefly of phosphate of lime, which, therefore, exists largenures in so many places; and it is by its aid alone also to exist in the bodies of all other animals.

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