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Caird. It must, therefore, be the interest of all placed at the head of this article, afford us the mapersons connected with agriculture, and especially terials for a satisfactory reply. of the owners of such land, to encourage the exten- Our readers are aware that botany, physiology, sion of this improved system, and by every means geology, meteorology, and mechanics, all lay claim, to diffuse the knowledge on which the profitable and with much justice, to the honor of having practice of the system depends.
greatly benefited general husbandry and those conBut more than this must 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 to the more palpable benefits which chemistry has profits of the cultivators of our most important dis already bestowed upon the agriculturist, and which tricts must certainly fall. It is not, therefore, to it is to be presumed are but samples of what it may high farming, in the abstract sense, that we can have still in store for him. 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 bet- of the movement still progress,) Johnston, and tered, or indeed maintained. We must raise more Boussingault--and we gave a general sketch of corn and cattle on the same surface, or we must the then known relations of this science to the raise the same quantities at a less cost.
various branches of rural practice. The cheinical And how is either of these things to be done? works we have placed at the head of the present
As in all the other arts by which this country article are such as have appeared since that time; has attained to eminence, it must be by the appli- and it is to some of the new matter contained in cation of more skill. If the United States of Amer- them that we now propose to address ourselves. ica are now beating us out of any of our old mar- The “ Contributions to Scientific Agriculture,” kets, it is not that they possess more energy than being the most recent of these publications, comwe do, more industry, or more intelligence, or have prises, as the introduction to the work informs us, cheaper labor ; but because, from their earnest a portion of the results of the researches which competition, they have in these cases been more have been carried on in the laboratory of the attentive to avail themselves of the daily discoveries author during the last five or six years; and a of science, and have accordingly so far succeeded rapid glance over its table of contents will show in producing better or cheaper articles.
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 indeed, in almost every process——throws light new strength. If other nations have outstripped upon every appearance-explains the qualities and her in any art, she, by the use of the same means, uses of all the materials which the husbandman may surely outstrip her present self. She has works with or produces, and aims at removing the only to carry out a little more zealously and gen- greater part of the difficulties which lie in his erously into agriculture the system by which her way. The culture of the land, the manuring of other manufacturing arts have been raised to their the crops, their value when reaped, the feeding present height; and the numerous cases of individ- and treatment of stock, the manufacture and manual distress which all fiscal and social changes agement of butter and cheese, have all been made involve—and which, we may add, all great national the subjects of analytical investigation in the lab triumphs bring along with them—will be swallowed oratory; and the practical applications of the up and disappear beneath the swelling tide of gen- results of numerous investigations of this kind are eral prosperity.
presented to us in the pages now before us. But what has science yet done for practical It is not our intention to advert to any of the agriculture to justify this opinion concerning its subjects of purely theoretical interest which are future use? This is a question which is still discussed in these pages. But we propose to asked, notwithstanding all that has not only been select, under the several branches of agriculture, written but performed of late years, showing the one or two points of a positive and material kind, relations of science to practical husbandry in its such as will illustrate the money value of science to largest sense. The works, of which the titles are 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 pine years ago, pounds, or, in other words, how much nitrogen, the popular and most valuable work of Liebig different vegetable productions usually containdrew 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 nnmber of years recently occupied itself in solving them. had passed, and extravagant hopes had not been It is the object of chemical research not merely realized, a violent reaction set in ; and, as is usual to explain known facts, but to remove misapprein such cases, we were told that nothing had been hensions and correct erroneous opinions. The done. Yet all the while a great deal had really recent determinations of the proportion of nitrobeen done, and was doing. Analytical researches gen contained in wheat have served both these were gradually shedding light upon practical op- purposes. Thus it was long asserted and believed, erations in every direction ; and it is the imme- that the wheat of warm climates always contained diate pecuniary profit, consequent on some of these more nitrogen, and was consequently more nutritive researches, which we are now desirous of making and of higher money value, than the wheat of our intelligible to our readers.
more temperate countries. But later researches First. The proportion of nitrogen* contained have corrected this hasty deduction, and have in different kinds of vegetable food, is a question placed our home wheat in its proper position, which is connected with numerous and various economical and nutritive, as compared with the economical considerations. This will appear by wheat of India, of Southern Australia, or of the a statement of the opinion at present entertained Black Sea. concerning the relation of nitrogen to the suste- Again : the British miller usually requires a nance of animal life.
portion of foreign wheat to mingle with our native Among the parts of the living animal, the mus- grain, both to make it grind more easily, and cles occupy an important place, not merely in bulk, to satisfy the baker with a flour which will stand but in reference also to the health and strength of much water. The pastry-cook, and the macaroni the body. The muscles contain nitrogen ; and, maker, also demand of him a four which will besides a little fat, are mainly composed of a sub- make a peculiarly adhesive dough. These several stance, to which, because of its stringy or fibrous qualities were supposed to be inherent only in nature, chemists give the name of fibrin. Now wheat which abounded, in an uncommon degree, this fibrin is almost identical, in chemical charac- in gluten, and which was produced under specially ters and composition, with the white of eggs, favorable conditions of soil and climate. Modern (albumen,) with the curd of milk, (casein,) with the chemistry has the merit of gradually removing glutent of wheat, and with certain similar sub- these misapprehensions, and of directing us to the stances which exist in beans, peas, barley, oats, true causes of all such differences. potatoes, turnips, cabbage, and, in fact, in almost So in regard to the superior amount of muscleevery vegetable esculent, in greater or less pro- forming matter supposed to exist in wheat in comportion. All these substances contain nearly the parison with other kinds of native grain, such as same per centage of nitrogen, and are distin- the oat. Experience had long taught the Scotch guished by the general name of protein com- that oats, such as they grow in their climate, are pounds.
a most nutritious food; but the habits of the more It is now ascertained that, when vegetable food influential English, and the ridicule of a prejis introduced into the stomach, the gluten, albu- udiced lexicographer, were beginning to make men, &c., which it contains, is dissolved and them ashamed of their national diet. Chemistry extracted from it, conveyed from the stomach into has here stepped in ; and, by her analysis of both, the blood, and by the circulating blood carried to has proved not only that the oat is richer in musthose parts of the body in which, owing to the cle-forming matter than the grain of wheat, but natural waste, or to the demands of animal growth, that oatmeal is, in all respects, a better form of the muscles require to be renewed or enlarged. nourishment than the finest wheaten flour. The power of a vegetable substance, therefore, to But what is more, chemistry has brought us increase or sustain the muscles of an animal, de- acquainted with the value of parts of the grain pends materially on the quantity of these protein formerly considered almost as waste. The husk compounds it contains-or on the quantity of nitro- or bran of wheat, for example, though given at gen by which that of the protein compounds is times to pigs, to millers' horses, and other cattle,
was usually thought to possess but little nutritive * Nitrogen is a kind of air which forms about four fifths of the bulk of our atmosphere.
virtue in itself. Analysis, however, has shown + When wheaten flour is made into dough, and this it to be actually richer in muscular matter than dough is washed with water upon a sieve as long as the the white interior of the grain. Thus the cause 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 ful purpose.
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.
In other districts, however, it is The true value of other kinds of food is also already an object of valuable though easy culture, established by these inquiries. Cabbage is a crop and large breadths of it are grown for the feeding which, up to the present time, has not been a gen- of stock, and yield profitable returns. Chemical eral favorite in this country, either in the stall or researches show its nutritive property to be very for the table, except during early spring or sum- great. Of muscle-building materials it contains
In North Germany and Scandinavia, how- when dry as much as thirty per cent., and is thereever, it appears to have been long esteemed ; and fore in this respect superior to beans, and inferior various modes of storing it for winter use have only to the cabbage. Under these circumstances we been very generally practised. But the cabbage can no longer doubt the conclusions at which some is one of the plants which has been chemically experimental feeders had previously arrived, nor examined, in consequence of the failure of the the advantage which might be obtained from the potato, with the view of introducing it into gen- more extensive cultivation of gorse on many poor eral use ; and the result of the examination is and hitherto almost neglected soils. both interesting and unexpected. When dried so The history of the Tussac grass is familiar to as to bring it into a state in which it can be com- most persons. A native of the Falkland Islands, pared with our other kinds of food, (wheat, oats, where it grows in the large tufts or tussacs from beans, &c.,) it is found to be richer in muscular which it derives its name, it is described as fattenmatter than any other crop we grow. Wheat con- ing in an extraordinary manner the stock, and tains only about 12 per cent., and beans 25 per especially the horses, which graze upon it. Some cent. ; but dried cabbage contains from 30 to 40 of the seeds which have been lately imported into per cent. of the so-called protein compounds. Ac- this country having vegetated, the grown-up plants cording to our present views, therefore, it is pre- have been analyzed ; and it was found " that the eminently nourishing. Hence, if it can but be proportion of muscle-forming ingredients in the made generally agreeable to the palate, and easy of dried grass is as great as in the best samples of digestion, it is likely to prove the best and easiest wheat, oats, or barley, and therefore that the grass cultivated substitute for the potato ; and no doubt is of a very nutritious character.” Thus its alleged the Irish kolcannon (cabbage and potatoes beat feeding qualities are confirmed ; and we may look together) derives part of its reputation from the forward to seeing it, on further trial, domesticated great muscle-sustaining power of the cabbage-a in Great Britain. property in which the potato is most deficient. The money value of the above investigations is
Further, it is of interest—of national impor- obvious enough—and we do not dwell upon them. tance, we may say—that an acre of ordinary land But the same branch of chemical inquiry deals with will, according to the above result, produce a questions of a larger and higher kind. We shall greater weight of this special kind of nourishment quote one or two illustrations of this from the main the form of cabbage than in the form of any terials before us. other crop. Thus, twenty tons of cabbage—and Among the articles imported in great quantity good land will produce, in good hands, forty tons into this country are the oily seeds of flax, rape, of drum-head cabbage on an imperial acre-con- mustard, &c., for the use of the oil-crusher-and tain fifteen hundred pounds of muscular matter; the refuse or cake from foreign oil-mills, for the while twenty-five bushels of beans contain only feeding of cattle. The importance of this cake, four hundred pounds; as many of wheat only two whether of home or of foreign manufacture, either hundred, twelve tons of potatoes only five hundred as a manure, or as food for cattle, is now well and fifty, and even thirty tons of turnips only a known. But chemical analysis has shown that its thousand pounds. The preference which some efficiency is owing to the large proportion of musfarmers have long given to this crop, as food for cular matter it contains, in addition to the oil which their stock and their milch-cows, is accounted for still remains in it. It has further shown that all by these facts; while, of course, they powerfully oily seeds, almost without exception, are equally recommend its more general cultivation as food rich in this kind of matter ; and thus a common for man.
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 batiled 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 ral state it may be used with advantage in feeding home markets is accounted for by its being mixed cattle and poultry.” This answer, accordingly, up with other cakes, and sold under another name. assigns the Darra its distinct place as a commer
New oil-cakes, too, have come into demand ; and cial article ; and thousands will be benefited by the same analyses which show their value as food, it, to whom the term chemistry is scarcely known, show also their value as manures. Hence the and to whom it would be almost impossible to refuse of seeds, which for special reasons cannot be convey an idea of the meaning of a chemical analyused for food, have found a ready sale among the sis. The same is the case in regard to Guinea traffickers in manures. Those of the castor-oil corn—which is grown extensively in Barbadoes bean, of the purging nut, (Jatropha purgans,) and and in other of our West India islands—and to even of the Croton tiglium, which yield the acrid the sweet quinoa, the native food of Peru and croton oil, have obtained access to our markets ; Western Mexico. Their nutritive quality has and form at once new articles of import and of been determined from samples imported for trial, traffic with other countries, and new means of im- their degree of adaption to our market pointed provement to our island husbandry. We save, out, and their true economical and commercial also, for the use of man, what has hitherto been value indicated. wasted as worthless.
With respect to the plantain, the native food of Other consequences have followed. The best another large portion of the earth, especially of the cakes being high in price, and their composition islands and shores of the Carribean Sea and of being known by analysis, it was asked—cannot an the Gulf of Mexico, a still more interesting quesartificial substitute be manufactured, equally good tion has been raised. In Dutch Guiana, which 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 ordi
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 ra, Durra, or Dhoora, is a very prolific ulus, they are made to perform more than an plant, yielding a small seed, from which a per-equivalent amount of labor, the plantain food given fectly white flour is prepared, and from which the them may prove insufficient, and the population inhabitants of the Upper Nile make a native beer. may diminish in a certain sensible ratio from this A quantity of the seed, lately brought into this cause alone.”— Contributions, p. 154. Thus the country, could find no sale, till chemistry had dilemma was shown to be only shifted. If the replied to the questions—what is its nutritive planter was relieved from the responsibility of this quality ? what grain does it most resemble ? for mortality in one form, it was to charge him with which of our common kinds of food may it be it in another. The food of the negro had become substituted, and in what proportion ?--since, on deficient, in consequence of the excess of labor the answers to these inquiries depended the price exacted from him. which should be paid for it. The answer is, that We may advert for a moment, before quitting “ it has a nutritive quality about equal to that of this part of our subject, to a domestic question, the average of our samples of wheaten flour; is which has been sometimes made a political one. void of sensible color, taste, or smell, and may When it is looked at from a more reasonable point therefore be ground up with wheat without any of view, it will be seen that one of the main elements 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 money value of the products of these manufactorecently occupied much of the public attention, ries—can be tested and ascertained. On points so and the profit of malting barley, before giving it universally acknowledged, therefore, we need not to stock, has been very much extolled. Now, it dwell—though the merits of chemistry in referhas been ascertained by chemico-physiological in-ence to them alone ought to have secured to it a quiries that a substance, when introduced into the much higher consideration with the agricultural stomach of an animal, may perform one or both of community, than has yet been conceded to it, for all two functions. It may contribute directly, and in the benefits it has conferred upon them. We will proportion to its weight, to the sustenance of the take an illustration rather from a subject in which animal, or it may assist the solution, digestion, chemistry and geology have played into each and consequent usefulness of other food consumed other's hands, and have entitled themselves, though along with it.
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 unfrestances 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 manure. own barley, and to feed with that grain alone- It is only within these few years that it has and wonld thus incur only one tenth of that loss been discovered that the nodules, of which we have of weight or substance which, as we have seen, spoken as occurring in the Crag, were to be met barley undergoes during its conversion into malt. with in some places in sufficient quantity to allow How far the duty on malt interferes with the gen- of their being dug up at a cheap rate : and it is literal market of the barley-grower, or whether it tle more than two years since they were first found would be worth his while to agitate, for the sake in the Greensand in such quantity as to promise to of the duty now payable on the trifling proportion be of use. But the trials which have been recentof the grain which he would retain in the shape ly made with these nodules (after being crushed of malt to feed his cattle with, are questions which and dissolved by means of sulphuric acid, as is now chemistry, of course, does not pretend to determine.
* When phosphorus is burned in the air, it gives off Secondly. Let us now briefly turn to the sub-acid. The white smoke which rises from a lucifer match,
white fumes, which are called by chemists phosphoric 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 to agriculture are at present pretty well under-burned, leave a bulky white ash, weighing about half as
lime, this acid forms phosphate of lime. Bones, when 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
chiefly of phosphate of lime, which, therefore, exists large
ly in ihe bodies of animals possessed of bones. It is found aures in so many places; and it is by its aid alone also to exist in the bodies of all other animals.