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The Stock-Feeder's Manual - the chemistry of food in relation to the breeding and - feeding of live stock
by Charles Alexander Cameron
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Is very Fat Meat wholesome?—The enormous and rapidly increasing demand for meat which characterises the food markets of these days, has reacted in a remarkable manner upon the nature of the animals that supply it. Formerly the animals that furnished pork, mutton, and beef, were allowed to attain the age of three years old and upwards before they were considered to be "ripe" for the butcher; but now sheep and pigs are perfectly matured at the early age of one year, and two-year-old oxen furnish a large quota of the "roast beef of old England." The so-called improvement of stock is simply the forcing of them into an unnatural degree of fatness at an early age; and this end is attained by dexterous selection and crossing of breeds, by avoidance of cold, by diminishing as much as possible their muscular activity, and lastly, and chiefly, by over-feeding them with concentrated aliments.

Every one knows that a man so obese as to be unable to walk cannot be in a healthy state; yet many feeders of stock look upon the monstrously fat bulls and cows of cattle show prize celebrity as normal types of the bovine tribe. It requires but little argument to refute so fallacious a notion. No doubt it is desirable to encourage the breeding of those varieties of animals which exhibit the greatest disposition to fatten, and to arrive early at maturity; but the forcing of individual animals into an unnatural state of obesity, except for purely experimental purposes, is a practice which cannot be too strongly deprecated. If breeders contented themselves with handing over to the butcher their huge living blocks of fat, the matter would not perhaps be very serious; but, unfortunately, it is too often the practice to turn them to account as sires and dams. Were I a judge at a cattle show, I certainly should disqualify every extremely fat animal entered for competition amongst the breeding stock. Unless parents are healthy and vigorous, their progeny are almost certain to be unhealthy and weakly; and it is inconceivable that an extremely obese bull and an unnaturally fat cow could be the progenitors of healthy offspring. We should by all means improve our live stock; but we should be careful not to overdo the thing. If we must have gaily-decked ponderous bulls and cows at our fat cattle exhibitions, let us condemn to speedy immolation those unhappy victims to a most absurd fashion; but in the name of common sense let us leave the perpetuation of the species to individuals in a normal state, whose muscles are not replaced by fat, whose hearts are not hypertrophied, and whose lungs are capable of effectively performing the function of respiration.

Mr. Gant, in a small volume[24] devoted wholly to the subject, describes the serious functional and structural disarrangements which over-feeding produces in stock. He found the heart of a one-year old Southdown wether, fattened according to the high-pressure system, to be little more than a mass of fat. In several other young, but so-called "matured" sheep, he found more or less fatty degeneration of the heart, and extensively spread disease of the liver and of the lungs. A four-year old Devon heifer, exhibited by the late Prince Consort at a Smithfield show, was found to be in a highly diseased state. It was slaughtered, and of course its flesh sold at a high price as "prize beef," but its internal organs came into Mr. Gant's possession. The substance of both ventricles of the heart had undergone all but complete conversion into fat; one of its muscles was broken up, and many of the fibres of the others were ruptured. In another animal the muscular fibres of the heart had given way to so great an extent that if the thin lining membrane (endocardium) had burst, death would have instantly ensued. The slightest exertion was likely to cause this catastrophe; but, fortunately enough in this case, the animal was not capable of exertion, for though under three years of age, it weighed upwards of 200 stones: this animal had received for some time before its exhibition, the liberal allowance of 21 lbs. of oil-cake (besides other food) per diem. "A pen of three pigs," says Mr. Gant, "belonging to his Royal Highness the Prince Consort, happened to be placed in a favorable light for observation, and I particularly noticed their condition. They lay helpless on their sides, with their noses propped up against each other's backs, as if endeavouring to breathe more easily, but their respiration was loud, suffocating, and at long intervals. Then you heard a short catching snore, which shook the whole body of the animal, and passed with the motion of a wave over its fat surface, which, moreover, felt cold. I thought how much the heart under such circumstances must be laboring to propel the blood through the lungs and throughout the body. The gold medal pigs of Mr. Moreland were in a similar condition, if anything, worse; for they snored and gasped for breath, their mouths being opened, as well as their nostrils dilated, at each inspiration. From a pig we only expect a grunt, but not a snore. These animals, only twelve months and ten days old, were marked 'improved Chilton breed.' They, with their fellows just mentioned, of eleven months and twenty-three days, had early come to grief. Three pigs of the black breed were in a similar state, at seven months three weeks and five days, yet such animals 'the judges highly commended.'"

Dr. Brinton denies the accuracy of several of Mr. Gant's statements relative to the structural changes in the muscles of obese animals; but I do not think that he has succeeded in disproving the principal assertions made by the latter.

There is conclusive evidence to prove that one of the effects of the present mode of fattening beasts is disease of the internal organs of the animals; but it is by no means certain that the flesh of those diseased animals is as unwholesome food as some writers assert it to be. The flesh of an over-fattened animal differs from that of a lean, or moderately fat one, in containing an exceedingly high proportion of fat; but it has not been proved that the fat of prize animals differs from the fat of lean kine, or that it is less wholesome or nutritious. Be the flesh of those exceedingly fat animals unwholesome or not, there are thousands, ay, millions of persons, to whom its greasy quality renders it peculiarly acceptable; and as for those who dislike fat—they do not usually invest their money in the flesh of prize sheep or oxen. At the same time, it must not be understood that all, or even a large proportion of fully matured stock is in a diseased state; though in most of them the vital and muscular powers are undoubtedly exceedingly low.

There is no doubt but that sheep and oxen, from three to five years old, moderately fat, and fairly exercising their locomotive powers, furnish the most savory, and, perhaps, the most nutritious meat: but if such were the only kind of meat in demand, it may be fairly doubted that the supply would be equal to it. The produce of meat in these countries has been rapidly increasing for many years past; and the weight of meat annually supplied from a given area of land is now from 80 to 100 per cent. greater than it furnished thirty or forty years ago. It is chiefly by means of the so-called forcing system that the produce of meat has been so considerably increased. If this system were abandoned, the production would be greatly diminished, and the consequently high price of the article would place it beyond the reach of the masses of the population. Besides, it has not been proved that the flesh of the animals brought early to maturity is much inferior, except somewhat in flavor, to the meat of three-year-old beasts. There is, no doubt, plenty of unwholesome meat offered for sale, but it is that of animals which were affected by diseases as likely to attack the young as the old. On the whole, then, we may say of the improved system of fattening stock, that it produces a maximum amount of meat on a given area of land; that the meat so produced is, except in rare cases, perfectly wholesome; that it is capable of supplying the ingredient—fat—which is almost wholly absent from a vegetable diet; and, finally, that it places animal food within the reach of the working classes.

Diseased Meat.—The losses occasioned to stockowners by the diseases of live stock are far greater than is generally supposed. It has been calculated that in the six years ending 1860, the value of the horned stock lost by disease amounted to L25,934,650. Pleuro-pneumonia was the chief cause of these losses. Exclusive of the enormous losses occasioned by the ravages of the rinderpest, the annual loss by disease in live stock in these countries for some years past cannot be much under L6,000,000 sterling.

Whether it is owing to the somewhat abnormal condition under which the domesticated animals are placed, or to causes which operate upon them when in a state of nature, it is certain that they are remarkably prone to disease. It is extremely difficult to get a horse six years old that is not a roarer or a whistler, or "weak on his pins," or in some way or other unsound. Oxen, sheep, and pigs have almost as many maladies afflicting them as human flesh is heir to, notwithstanding the short period of life which they are permitted to enjoy.

It is a very serious question whether or not the flesh of animals that have been killed while they are in a diseased condition is injurious to health. The opinions on this point are conflicting, but the majority of medical men believe that the flesh of diseased animals is not wholesome. There are certain maladies which obviously render meat unsaleable, by causing a sensible alteration in its quality. For example, blackleg in cattle and measles in the porcine tribe render the flesh of these animals, as a general rule, unmarketable, or nearly so. But there are very serious diseases—often proving rapidly fatal—which, whilst seriously affecting certain internal organs, do not palpably deteriorate the quality of the flesh. In such cases are we to rely upon the evidence of our mere senses in judging of the wholesomeness of the meat? If we find beef possessing a good color and odour, and firm to the touch, and appearing to be in every respect healthy flesh, are we under such circumstances to take it for granted that it must be healthy? This is a very important question, involving as it does the interests of both the producers and consumers of animal food. If the flesh of all diseased animals be unwholesome, a very large number of oxen now sold whilst laboring under pleuro-pneumonia should not be sent into the market. This, of course, would be a heavy loss to the stockowner, but a still heavier one to the meat consumer; because, if there were fewer animals for sale, the price of meat would ascend, in obedience to the law of supply and demand. The whole question is, then, well worthy of being considered in the most careful, unbiassed, and scientific manner; for at present it is in a state which is the reverse of being satisfactory.

A large proportion of the animals conducted to the shambles is in a diseased condition. Professor Gamgee estimates it at no less than one-fifth. Dr. Letheby, food analyst to the Corporation of London, condemns weekly about 2,000 pounds weight of flesh; but as his jurisdiction is limited to the "City," which contains a population of only about 114,000, the 2,000 pounds of diseased meat are probably only about 1-30th of the quantity exposed for sale within the whole area of the metropolis. Making an estimate of the most moderate kind, we may assume that 30,000 pounds weight of bad meat are weekly offered for sale in London—three million pounds weight annually.

Many persons have been affected with dysentery and choleraic symptoms after partaking of butcher's meat of apparently the most healthy kind. The meat has often been subjected to minute chemical and microscopical examination, but no poison has been discovered. But these cases are becoming so frequent that they are exciting uneasiness, and demand an exhaustive investigation. The unskilful persons who officiate in the capacity of "clerks of the market" and inspectors of meat can only judge of the quality of flesh that is obviously inferior to the eye, nose, or touch; but are there not cases where the flesh may appear to be good, and yet contain some subtle malign principle? It is an ascertained fact that young or "slink" veal very frequently gives rise to diarrhoea, more especially when that disease is epidemic. Dr. Parkes, in his celebrated work on Hygiene, page 162 (second edition), states that "the flesh of the pig sometimes produced diarrhoea—a fact I have had occasion to notice in a regiment in India, and which has often been noticed by others. The flesh is, probably, affected by the unwholesome garbage on which the pig feeds." Menschell states that 44 persons were afflicted with anthrax after eating the flesh of oxen affected with carbuncular fever. Dr. Kesteren, in the Medical Times for March, 1864, mentions a case where twelve persons were affected with choleraic symptoms after the use of pork not obviously diseased. At Newtownards, county of Down, several persons died after eating veal in which no poisonous matter of any kind could be detected. One instance has come under my own notice where a man, two dogs, and a pig died after eating the flesh of an animal killed whilst suffering from splenic apoplexy. Several butchers have lost their lives in consequence of the blood of diseased animals being allowed to come in contact with abrasions or recently received wounds on their arms. The flesh of over-driven animals is stated by Professor Gamgee to produce a most serious skin disease, although the meat appeared to be perfectly healthy. The Belgian Academy of Medicine has decided that the flesh of animals suffering from carbuncular fever is unwholesome, and its sale in that country is prohibited.

Many persons have died in Germany and a few in England from a disease produced by eating pork containing a small internal parasite termed trichina spiralis. I have recently met with a case of trichiniasis in the human subject. The body of the unfortunate person—who had been an inmate of the South Dublin Union Workhouse—was found to contain thousands of the trichinae. In Iceland a large proportion of the population suffers from a parasitic disease traceable to the use of the flesh of sheep and cattle in which flukes abound.

Pleuro-pneumonia is in this country the disease which most frequently affects the ox. It is probable that about 5 per cent. of these animals sold in Dublin are more or less affected by this malady. There are two forms of pleuro-pneumonia—the sporadic, or indigenous, and the foreign, or contagious. It is the latter form which has become the scourge of the ox tribe in this country, though unknown here until the year 1841, when it appeared as an epizooetic, and carried off vast numbers of animals.

The contagious pleuro-pneumonia is an extremely severe inflammatory disease, and is produced—not in the same way that common pleuro-pneumonia is, by exposure to excessive cold, &c.—but by a blood poison received from an infected animal. In the congestive stage of the disease there is no structural alteration in the organs of the animal, and if well bled its flesh might (probably) be safely eaten; but when a large portion of the lungs becomes solidified, and rendered incapable of purifying the blood, is it not doubtful, to say the least, that the blood or flesh is perfectly wholesome? The blood, during the life of the animal, is in a state of fermentation; there is extreme fever, and the animal presents all the characteristic symptoms of acute disease. On being killed, the flesh, if the disease be of a fortnight's duration, will usually be extremely dark, but in a less advanced stage of the malady the flesh will generally present a healthy appearance. Is it really so? That is the question which science has to determine. Going upon a broad principle, I can hardly conceive that so serious a disease as pleuro-pneumonia does not injuriously affect the quality of the flesh. It is no argument to say that thousands consume such flesh, and yet enjoy good health. Millions of people drink water and breathe air that are extremely impure, and yet they do not speedily die. It is one thing to be poisonous, another to be unwholesome. The flesh of animals killed whilst suffering from lung distemper is not directly poisonous, but who can prove that it is not, like bad water, unwholesome?

As analyst to the city of Dublin, I am almost daily called upon to inspect meat suspected to be unwholesome; and I have always condemned as being unfit for human food:—

1. Animals slaughtered at the time of bringing forth their young.

2. Oxen affected with pleuro-pneumonia, when pus is present in the lungs, or the flesh obviously affected; animals suffering from murrain, black-quarter, and the different forms of anthrax.

3. Animals in an anaemic, or wasted condition.

4. Meat in a state of putrefaction.

During the present year about 20,000 pounds weight of meat have been seized and condemned in the city of Dublin.

SECTION II.

MILK.

Milk is a peculiar fluid secreted by the females of all animals belonging to the class Mammalia; and, being designed for the nourishment of their offspring, contains all the constituents which enter into the composition of the animal body.

The milk of different animals varies very much in color, taste, and nutritive value. That of the cow is a little heavier than water—its specific gravity being, on the average, about 1.030, water being 1.000. It is composed of three constituents—namely, butter, curd, and whey—each of which is also composed of a number of substances. These three constituents are of unequal weight, or specific gravity, and their separation is the chief process carried on in the dairy. The butter is the lightest and the curd is the heaviest constituent.

The following table represents the composition of the milk of different animals:—

COMPOSITION OF THE MILK OF DIFFERENT ANIMALS.

1,000 PARTS CONTAIN—

+ -+ + + + -+ -+ - Specific Gravity, Water. Solid Cheesy Sugar. Butter. Mineral or Ingredients. Matter. Matter. Density. + -+ + + + -+ -+ - Woman 1032.67 889.08 110.92 39.30 43.68 26.66 1.30 Cow 1030 864.20 135.80 48.80 47.70 31.30 6.00 Goat 1033.53 844.90 155.10 35.14 36.91 56.87 6.18 Ewe 1040.98 832.32 167.68 69.78 39.43 51.31 7.16 Mare 1033.74 904.30 95.70 33.35 32.76 24.36 5.23 Ass 1034.57 890.12 109.88 35.65 50.46 18.53 5.24 Bitch 1041.62 772.08 227.92 116.88 15.29 87.95 7.80 + -+ + + + -+ -+ -

Milk examined through a microscope is a colorless fluid, containing a large number of little vesicles, or bags, filled with butter—a mixture of oily and fatty matters. When the milk stands for some time, the globules, being lighter than the other constituents, ascend to the top, and, mixed with a certain proportion of milk, are removed as cream. The curd is termed in scientific parlance casein, and is in fresh milk in a state of solution—that is to say, is dissolved in milk in the same way that we dissolve sugar in water. When milk becomes sour, either naturally or by the addition of rennet, it can no longer hold casein in solution, and the curd consequently separates. Casein is the substance which forms the basis of cheese. The substance that remains after the removal of the butter and cheese is called serum, or whey, and is composed of a sweetish substance termed sugar of milk, and certain saline bodies, termed the ash, dissolved in water.

The butter and the sugar of milk are employed in the animal economy in the production of fat, and are what have been styled by physiologists heat-producers and fat-formers. The casein resembles the gluten of wheat in composition; it belongs to the class of food substances termed flesh-formers. The ash, or mineral part of the milk, is chiefly employed in forming the bones of the young animals it is destined to nourish.

The quality of milk is influenced by the quantity and quality of the food given to the animal. The milk of cows fed on distillery wash, turnip, and mangel tops, coarse herbage, and other kinds of inferior food, is always of inferior quality. Hence it is of great importance that dairy stock be kept in good old pastures in summer, and fed on Swedish turnips, mangel-wurtzel, and oil-cake during winter. It is true economy to supply dairy cows with abundance of nutritious food; and it should be constantly borne in mind that the milk from two well-fed cows will give more butter than can be obtained from the produce of three badly-fed animals.

The butter is the constituent of milk which is most affected by the nature and amount of the animal's food; and butter is precisely the article which is of the greatest importance to the Irish dairy farmer, as the quantity of cheese prepared in this country is inconsiderable. When, therefore, it is found that a cow pastured on inferior land, or badly fed in the byre, yields a large supply of milk of a high specific quantity (which, however, is rarely the case), it must not be concluded that the result is satisfactory; for if such milk be tested by the lactometer it will certainly be found wanting in butter. The average composition of English milk, according to Way, is:—

Water 87.02 Butter 3.23 Casein 4.48 Sugar of milk 4.67 Ash 0.60 ——— 100.00

In several analyses of milk published by Professor Voelcker, the highest proportion of butter is stated to be 7.62. In that of cows kept on poor and over-stocked pastures less than 2 per cent. was found. I have examined in my capacity of Food Analyst to the City of Dublin several hundred samples of milk, in not one of which have I found the proportion of butter to amount to more than 5.6 per cent. In no sample did I find a higher per-centage of solid matter than 13.15, or (when pure) lower than 12.08. The quality of the food of the milch cow exercises a great influence on the quality and yield of her milk. Aliments rich in fat and sugar favor the production of butter, and augment the supply of milk. Locust-beans, malt, and molasses are good milk-producing foods; but the chief condition in the production of milk rich in butter is simply that the animals which yield it must be fed with abundance of nutritious food. Nor must it be supposed that the richness of milk is due to the smallness of the yield, for whenever the quality of the secretion is inferior, it is almost certain to be deficient in quantity. Those cows which give the richest milk, generally yield the largest quantity.

Yield of Milk.—According to Boussingault, a cow daily yields on the average 10.4 parts of milk per 1,000 parts of her weight. Morton, in his "Cyclopaedia of Agriculture," p. 621, states that Mr. Young, a Scotch dairy keeper, obtained 680 gallons per cow per annum. Voelcker found that some common dairy stock gave each of them fifty-two pints of milk per diem, whilst three pedigree cows yielded respectively forty-nine pints.

Professor Wilson gives the following information on this point:—

Our principal dairy breeds are the Ayrshire, the Channel Islands, the Short-horn, the Suffolk, and the Kerry. Some published returns of two dairies of Ayrshire cows give the annual milk produce per cow at 650 and 632 gallons respectively. Three returns of dairies, consisting wholly of Short-horns, show a produce of 540 gallons, 630 gallons, and 765 gallons respectively, or an average of 625 gallons per annum for each cow. In two dairies, where half-bred Short-horns were kept, the yield was 810 and 866 gallons respectively for each cow. In four dairies in Ireland, where pure Kerrys and crosses with Short-horns and Ayrshires were kept, the annual produce per cow was returned at 500 gallons, 600 gallons, 675 gallons, and 740 gallons respectively; or an average, on the four dairies, of 630 gallons per annum for each cow. A dairy of "pure Kerrys" gave an average of 488 gallons per cow, and another of the larger Irish breed gave an average of 583 gallons per head per annum. In the great London dairies, now well-nigh extinguished by the ravages of the cattle disease, these returns are greatly exceeded. The cows kept are large framed Short-horns and Yorkshire crosses, which, by good feeding, bring the returns to nearly 1,000 gallons per annum for each cow kept. The custom in these establishments is to dispose of a cow directly her milk falls below two gallons a-day, and buy another in her place.

The following milk return of one of our best managed dairy farms (Frocester Court) shows the relative produce of cows in the successive years of their milking. The first lot was bought in at two-years old; all the others at three years:—

No. of Cows. Year of Milk. Produce per head.

8 1st 317 gals. 15 1st 472 " 14 2nd 353 " 15 3rd 616 " 20 4th 665 " 18 5th 635 " 9 6th 708 " 15 Old 651 "

The maximum reliable milk produce that we have recorded was that of a single cow belonging to the keeper of the gaol at Lewes, the details of which were authenticated by the Board of Agriculture. In eight consecutive years she gave 9,720 gallons, or at the rate of more than 1,210 gallons per annum. In one year she milked 328 days, and gave 1,230 gallons, which yielded 540 lbs. of butter, or at the rate of 1 lb. of butter to 22-3/4 lb. of milk. In the early part of the present year (1866) a return was published of the produce of a cow in a Vermont (U.S.) dairy, which was stated to have given, in the previous year, a butter yield of 504 lbs., at the rate of 1 lb. of butter to 20 lbs. of milk.[25]

Preserved Milk.—Various plans have been proposed to render milk more portable, and to preserve it sweet for days and even months. Mr. Borden of Connecticut, United States, prepares a concentrated milk by boiling the fluid down in vacuo, at a temperature under 140 deg. Fahrenheit, mixing the resulting solid with sugar, and rapidly placing the compound in tins, which are then hermetically sealed. It is said that solidified milk prepared by this process remains sweet for many months. In France, solidified and concentrated milk are largely prepared; and it is certain that London and other large towns will yet be supplied with milk rendered portable and more stable, by the removal of a large proportion of its water. In many parts of Ireland pure milk could be bought at from 7d. to 8d. per gallon. I do not despair to see factories established in such places for the manufacture of preserved milk as a substitute for the dear and impure fluid sold under the name of milk in London and other large cities. It is stated that solidified milk prepared in Switzerland is now sold in London.

SECTION III.

BUTTER.

History of Butter.—The very general use of butter as an article of food is demonstrated by the familiar saying—"We should not quarrel with our bread and butter"; yet this article, now so commonly used throughout the greater part of Europe, was either unknown or but imperfectly known to the ancients. In the English translation of the Holy Scriptures the word butter does certainly frequently occur; but the Hebrew original is chamea, which, according to the most eminent Biblical critics, signifies cream, or thick, sour milk. In the 20th chapter of Job the following passage occurs:—"He shall not see the rivers, the floods, the brooks of honey and butter." Now, we can conceive streams of thin cream, but we cannot imagine a river of butter. The oldest mention of butter is found in the works of Herodotus. In the description of the Scythians given by this ancient author, reference is made to their practice of violently shaking the milk of their mares, for the purpose of causing a solid fatty matter to ascend to its surface, which, when removed from the milk, they considered a delicious article of food. Hippocrates, who wrote a little later than Herodotus, describes, but in clearer language, the manufacture of butter by the Scythians; he also alludes to the preparation of cheese by the same people. The word, butter, does not occur in any of Aristotle's writings, and although mention is made of it in the works of Anaxandrides, Plutarch, and AElian, it is evident that they considered it only in the light of a curious substance, employed partly as an article of food, partly as a medicinal salve, by certain barbarous nations. About the second or third century, butter was but little known to the Greeks and Romans, and there is no reason to believe that it was ever generally used as an article of food by the classic nations of antiquity; it is noteworthy, that the inhabitants of the south of Europe even at the present time use butter in very small quantities, which, indeed, is often sold for medicinal purposes in the apothecaries' shops in Italy, Spain, and Portugal. From the foregoing statements it is evident that the butter manufacture can lay no claim to a classic origin; but that it took its rise in the countries of savage, of semi-civilised, and barbarous nations. It is probable that the Greeks were made acquainted with butter by the Thracians, Phrygians, and Scythians; and that the knowledge of this substance was conveyed to Rome by visitors from Germany. During the middle ages the practice of butter-making spread throughout Northern, Central, and Western Europe; but in many parts the commodity was very scarce and highly valued, notwithstanding its being almost, if not quite, in a semi-fluid state, instead of possessing the firm consistence of the butter of the present day.

Irish Butter.—Butter is produced in such large quantities in Ireland that, after the home demand has been supplied, there remains a large excess—so considerable, indeed, as to constitute one of the more important of our few commercial staples. The precise quantity of butter which, during late years, has been annually exported from Ireland is unknown. The greater part of the commodity is sent to trans-Channel ports; and, there being no duty on butter in the cross-Channel trade since 1826, we have no means of accurately estimating the amount of our exports to Great Britain. If, however, we refer to the statistics of our commerce for the period beginning in 1787, and ending in 1826, we shall find that the exportation of butter was enormous, and that a large proportion of that commodity consumed by the army and navy was supplied from the dairies of Ireland. During the three years ended on the 5th of January, 1826, the average annual amount of butter exported was as follows:—

cwts.

To Great Britain 441,226 To foreign countries 51,637

Of late years the exportation to foreign and colonial countries has fallen off; still the export trade is very considerable, probably amounting to 450,000 cwts. per annum. During the year 1867, the imports of foreign butter into Great Britain amounted to 1,142,262 cwts.

I have quoted the above statistics for the purpose of demonstrating the great importance of the butter trade to this country. Not only is a large proportion of the agricultural community pecuniarily interested in the production of this article, but the exportation is the chief cause of the commercial prosperity of a city, which, in point of population, ranks third in the kingdom. If butter, then, be an article of so much importance, it is obvious that the greatest care should be taken in its preparation, and that the efforts of both scientific and practical men should be directed towards the best mode of improving its quality. If the principles involved in the production of butter were thoroughly understood, and generally known, I believe that such terms as "seconds," "thirds," and "fourths," would speedily fall into disuse; that there would be only one kind of butter sent into the market; and that the article would always be of the best quality, in other words, "firsts."

Composition of Butter.—The composition and quality of butter depend to a great extent upon the condition of the milk or cream from which it is prepared, and on the skill and cleanliness of the dairy-maid. It consists essentially of fatty and oily matters, but it is always found in combination with casein (cheesy matter) and water. The following analyses, made by Mr. Way, late consulting chemist to the Royal Agricultural Society of England, shows its composition:—

INGREDIENTS PER CENT.

1. 2. 3.

Fatty matters 82.70 79.67 79.12 Casein 2.45 3.38 3.37 Water 14.85 16.95 17.51

No. 1 analysis shows the composition of a specimen obtained from the well-known Mr. Horsfall's dairy. It was made from raw cream. The other specimens were the produce of a Devonshire dairy, and were prepared from scalded cream. In several specimens of well-made and unsalted Irish butter which I have analysed, I found the proportion of casein or cheesy matter never to exceed 1 per cent., whilst in the analysis above stated the centesimal amount is on the average more than 3 per cent.

The fatty matter is composed of two substances—one, a solid, termed margarin; the other fluid, and styled by chemists elaine. The solid fat is identical in composition with the solid fat of the human body. The elaine is peculiar to milk, but it differs very slightly from olein, or fluid fat. The relative proportions of the fluid and solid fats vary with the seasons. According to Braconnot, the solid fat forms in summer 40 per cent. of the butter, but in winter the proportion rises to 65. This decrease in the proportion of the liquid fat in winter is the cause of the greater hardness of the butter in that season, which is often incorrectly attributed solely to the cold.

The cheesy and acid matters contained in butter are by no means essential; on the contrary, if it were quite free from them, it might be retained with little or no salt for a very long period without becoming rancid. The cheesy matter contains nitrogen; and nearly all the substances into which this element enters as a constituent are remarkably prone to decomposition. Yeast, and ferments of every kind—gunpowder, fulminating silver, chloride of nitrogen—and almost every explosive compound, contain this element. The cheesy matter is a very nitrogenous body, and in presence of air and moisture not only rapidly decomposes, or decays, itself, but induces by mere contact a like state of decomposition in other substances—such, for instance, as fat, sugar, and starch, which naturally have no tendency to change their state. Bearing the foregoing facts in mind, it is obvious that the chief precautions to be observed in the manufacture of butter are:—Firstly, to separate to as great an extent as practicable the casein from the butter; and, secondly, as in practice a small portion of the curd remains in the butter, to prevent it from undergoing any change—at least for a prolonged period. How these desiderata may best be accomplished I shall now proceed to point out.

The Butter Manufacture.—The theory of the process of churning is very simple. By violently agitating the milk or cream the little vesicles, or bags containing the butter, are broken, and, the fatty matter adhering, lumps of butter are formed. The operation of churning also introduces atmospheric air into the milk, which, aided by the high temperature to which the fluid is raised, converts a portion of the sweet sugar of milk into the sour lactic acid. By the alteration produced in this way in the composition of the milk, it is no longer capable of holding the casein in solution, and the curd therefore separates.

The churn and other vessels in which the milk is placed cannot be kept too clean. No amount of labor bestowed on the scalding and scrubbing of the vessels is excessive. When wood is the material used in the milk-pans the utmost care should be taken in cleaning them, as the porous nature of the material favors the retention of small quantities of the milk. A simple washing will not suffice to clean such vessels. They must be thoroughly scrubbed and afterwards well scalded with boiling water. Tin pans are preferable to wooden ones, as they are more easily cleaned, but in their turn they are inferior to glass vessels, which ought to supersede every other kind. Earthenware, lead, and zinc pans are in rather frequent use. The last-mentioned material is easily acted upon by the lactic acid of the sour milk, and is, therefore, objectionable. It is a matter of great importance that the dairy should not be situated near a pig-stye, sewer, or water-closet, the effluvia from which would be likely to taint the milk. It is surprising how small a quantity of putrescent matter is sufficient to taint a whole churn of milk; and as it has been demonstrated that the almost inappreciable emanations from a cesspool are capable of conferring a bad flavor on milk, it is in the highest degree important to remove from the churn and milk-pail every trace of the sour milk. I go further, it is even desirable that no one whose hands have a tendency to perspire should be allowed to manipulate in the dairy; and it should be constantly borne in mind that the dairy-maid's fingers and hot water should be on the most intimate visiting terms.

Butter is made either from cream—sour and sweet—or from whole milk which has stood sufficiently long to become distinctly sour. It is asserted by some makers that butter prepared from whole milk, or from scalded cream, contains a large proportion of curd. If this be true—which I greatly doubt—it is a serious matter, for such butter would speedily become rancid in consequence of the casein acting as a ferment. I believe that experience points to an exactly opposite conclusion. From the results of careful inquiries I feel no hesitation in asserting that the butter should not be made from the cream, but from the whole milk. When made from the cream alone it is much more likely to acquire a bad taste, and is generally wanting in keeping qualities. I have no doubt but that in the process of churning the whole milk there is a large amount of lactic acid formed, and a much higher temperature attained, than in the churning of cream; consequently, the separation of caseous matter must be more perfectly effected in the former than in the latter case. It is a mistake to think that there is very little casein in cream: out of 7 or 8 lbs. of thick cream only a couple of pounds of butter are obtainable; the rest is made up of water, casein, and sugar of milk. The yield of butter is greater when the whole milk is churned than when the cream alone is operated upon, and, what is of great importance, the quality of the butter is uniform during the whole year. The labor of churning whole milk is, of course, much greater than if the cream alone were employed, but the increased yield and unvarying quality of the butter more than compensate for the extra expenditure of labor.

The proper temperature of the milk or cream is a point of great practical importance. If the fluid be too warm or too cold the buttery particles will only by great trouble be made to cohere; and the quality of the butter is almost certain to be inferior. When the whole milk is operated on, the temperature should be from 55 to 60 degs. of Fahrenheit's thermometer; and if cream be employed the temperature should never exceed 55 degs. nor be lower than 50 degs. Hence it follows that in summer the dairy should be kept cooler, and in winter warmer, than the atmosphere. The temperature of milk is raised or lowered as may be found necessary, by the addition of hot or cold water—in performing which operations properly, a good thermometer is indispensable; one should always be kept in the dairy, and should be so constructed as to admit of being plunged into the milk. In some dairies the water, instead of being mixed with the milk, is put into a tub in which the churn is placed. There is a good kind of churn, which consists of two cylinders, the one within the other—the interval between them being intended for the reception of hot or cold water. The influence of temperature upon the production of butter has been placed beyond all doubt by numerous carefully-conducted experiments. Mr. Horsfall, a celebrated dairy farmer, in discussing this question, sums up as follows:—"By a series of carefully-conducted experiments at varying temperatures, I am of opinion that a correct scale of the comparative yield of butter at different temperatures might be arrived at; as thus: From a very low degree of temperature little or no butter; from a temperature of about 38 degs., 16 oz. from 16 quarts of milk; ditto, 45 degs., 21 oz. from 16 quarts of milk; ditto, 55 degs., 26 to 27 oz. from 16 quarts of milk." This is a higher yield of butter than, I suspect, most dairymen get: but Mr. Horsfall's cows being of the best kind for milking, and well fed, the milk is, of course, rich in butter; and his experiments prove that even the richest milk will not throw up its butter unless at a certain temperature.

In the churning of cream the motion should be slow at first until the cream is thoroughly broken up. In churning milk the agitation should neither be violent nor irregular; about 40 or 50 motions of the plunger or board per minute will be sufficient. In steam-worked churns the motion is often excessively rapid, and the separation of the butter is effected in a few minutes; but the article obtained in this hasty way very quickly becomes rancid, and must be disposed of at once. An hour's churning of sour cream appears in general to produce good butter. Sweet cream and whole milk require a longer period—the latter about 3 hours—but in any case prolonged churning is certain, by incorporating cheesy matter with the butter, to produce an inferior article.

Sweet milk becomes sour, evolves a considerable quantity of gas during churning, and its temperature ascends four or five degrees. Oxygen is unquestionably absorbed, and it is probable that a portion of the sugar of milk is converted into acid products.

I have already stated that even the most carefully prepared butter contains a small proportion of casein and sugar of milk. This casein is the good genius of the cheese-maker, but the evil genius of the butter manufacturer. How? In this way:—When butter containing a notable proportion of casein and sugar of milk is exposed to the air, the following changes take place: the casein passes into a state of fermentation, and acting upon the sugar of milk, converts it, firstly into the bad-flavored lactic acid, and secondly into the bad odorous butyric, capric, and caproic acids. The first of these compounds in a state of purity emits an odor resembling a mixture of vinegar and rancid butter; the second possesses an odor resembling that of a goat—hence the name capric; the third has an odor like that of perspiration. In addition to these acids, there is another simultaneously generated—the caprylic, but it does not unpleasantly affect the olfactory nerve. The casein also injuriously affects the fatty constituents of the butter; under its influence they absorb oxygen from the air, and become converted into strong-smelling compounds. The washing of butter is intended to free it from the casein and unaltered cream, and the more perfectly it is freed from those impurities the better will be its flavor, and the longer it will remain without becoming rancid. Some people believe that too much water injures the quality and lessens the quantity of butter. It cannot do the former, because the essential constituents of butter are totally insoluble in water; it may do the latter, but, if it do, so much the better, because the loss of weight represents the amount of impurities—milk, sugar of milk, &c.—removed.

I have already remarked that butter is so susceptible of taint that even a perspiring hand is sufficient to spoil it; naturally cool hands should alone be allowed to come in contact with this delicate commodity, and the hands should be made thoroughly clean by repeated washings with warm water and oatmeal—the use of soap in the lavatory of the dairymaid being highly objectionable. Wooden spades are now being commonly made use of in manipulating the butter, and there is no good reason why they should not come into universal use.

The yield of butter per cow is subject to great variation. Some breeds of the animal are remarkable as milkers; such, for instance, as the Alderneys and Kerrys—indeed, I may say all the small varieties of the bovine race. There are instances of cows yielding upwards of twenty pounds of butter per week, but these are extraordinary cases. In Holland a good cow will produce, during the summer months, more than 180 lbs. of butter. In these countries I think the average annual yield of a cow is not more than 170 lbs. It sometimes happens that cows yield a large quantity of milk and a small amount of butter, but it far more frequently occurs that the cow which gives most milk also yields most butter.

An estimate of the amount of butter contained in milk may be made by determining the amount of cream. This may be effected by means of an instrument termed a lactometer, which is simply a glass tube about five inches long, and graduated into a hundred parts. The specimen to be examined is poured into this tube up to zero or 0, and allowed to stand for twelve hours in summer and sixteen or eighteen in winter. At the end of that time the cream will have risen to the top, and its per-centage may be easily seen. In good milk the cream will generally extend 11 to 15 degrees down from 0. This instrument, although very useful, is not reliable in every case, especially in detecting the adulteration of milk.

I have already stated that the complete separation of the butter from the other constituents of the milk is never accomplished in the dairy. Now although the proportion of curd in the butter is very small—rarely more than two per cent. and often not a fourth of one per cent.—yet it is more than sufficient, under a certain condition, to cause the butter to become speedily rancid. That condition is simply contact with the air. If the curd, before it becomes dry and firm, is subjected to the influence of the air, it rapidly passes into a state of fermentation, which is very soon communicated to the fatty and saccharine constituents of the butter (substances not spontaneously liable to sudden changes in composition) and those peculiar compounds—such, for example, as butyric and capric acids, are generated, which confer upon rancid butter its characteristic and very disagreeable odor and flavor. The fermentation of the curd is prevented by incorporating common salt with the butter, and by preventing, so far as possible, the access of air to the vessels in which the article is placed. If fresh butter be placed in water—which apparently protects it from the influence of the air—it will soon become rancid. The reason of this is, that water always contains air, which differs in composition, though derived, from the atmosphere, by being very rich in oxygen. Now, it is precisely this oxygen which effects those undesirable changes in the casein, or curd, to which I have so repeatedly referred; hence its presence in a concentrated state in water causes that fluid to produce an injurious effect on the butter placed in it. A saturated solution of salt contains very little air, and, so long as the curd is immersed therein, it undergoes no change. The salt, too, acts as a decided preservative; for although it was long considered to be capable of preserving animal matters, merely by virtue of its property of absorbing water from them (the presence of water being a condition in the decomposition of organic matter), it has lately been shown to possess very antiseptic properties.

The mixing of the salt with the butter is effected in the following manner:—The butter, after being well washed, in order to free it from the butter-milk, is spread out in a tub, and the salt shaken over it; the butter is then turned over on the salt by the lower part of the palm of the hand, and rubbed down until a uniform mixture is attained. A good plan in salting is to mix in only one half of the quantity of salt, make up the butter in lumps, and set them aside until the following day; a quantity of milk is certain to exude, which is to be poured off, and then the rest of the salt may be incorporated with the butter.

According to butter-makers, the quality of the article is greatly dependent on the quality of the salt used in preserving it. I think there is a good deal of truth in this belief, and I therefore recommend that only the very best and driest salt should be used in the dairy. Common salt is essentially composed of the substance termed by chemists chloride of sodium, but it often contains other saline matters (chloride of magnesium, &c.), some of which have a tendency to absorb moisture from the air, and to dissolve in the water so obtained. These salts are termed deliquescent, from the Latin deliquere, to melt down. When, therefore, common salt becomes damp by mere exposure to the air, it is to be inferred that it contains impurities which, as they possess a very bitter taste, would, if mixed with butter, confer a bad flavor upon it. The impurities of salt may be almost completely removed by placing about a stone weight of it in any convenient vessel, pouring over it a quart of boiling water, and mixing thoroughly the fluid and solid. In an hour or two the whole is to be thrown upon a filter made of calico, when the water will pass through the filter, carrying with it all the impurities, and the purified salt, in fine crystals, will remain upon the filter. The solution need not be thrown away: boiled down to dryness it may be given as salt to cattle; or, if added in solution to the dung-heap, it will augment the fertilising power of that manure.

The proportion of salt used in preserving butter varies greatly. When the butter is intended for immediate use, I believe a quarter of an ounce of salt to the pound is quite sufficient; but when designed for the market, about half an ounce of salt to the pound of butter will be sufficient. Irish butter at one time commanded the highest price in the home and foreign markets, but latterly it has fallen greatly in public estimation; indeed, at the present moment the price of Irish butter at London is nearly twenty shillings per cwt. under that of the Dutch article. It is really painful to be obliged to admit that the Irish farmer is solely to blame for this remarkable depreciation in the value of one of our best agricultural staples. In a word, by the stupid (and recent) practice of putting into butter four times the quantity of salt necessary to its preservation, the Irish dairy farmers—or at least the great majority of them—have completely ruined the reputation of Irish butter in those very markets in which, at one time, the Cork brand on a firkin was sufficient to dispose of its contents at the very highest price. It is a great mistake to think that the greater the quantity of salt which can be incorporated with the butter, the greater will be the profit to the producer. No doubt, every pound of salt sold as a constituent of butter realises a profit of two thousand per cent.; but then the addition of every pound of that substance, after a certain quantity, to the cwt. of butter depreciates the value of the latter to such an extent as to far more than neutralise the gain on the sale of salt at the price of butter. In the county of Carlow, less salt is used in preserving butter than is the case in the county of Cork and the adjacent counties; the price, therefore, which the Carlow commodity commands in the London market is higher than that of the Cork butter: but in every part of Ireland the proportion of salt added to the butter is excessive.

The results of the analyses of butter supplied to the London market, made by the Lancet Analytical Commission, showed that the proportion of salt varied from 0.30 to 8.24 per cent. The largest proportion of salt found in fresh butter was 2.21 and the least 0.30. In salt butter the highest proportion of salt was 8.24 and the lowest 1.53. The butter which contained most salt was also generally largely adulterated with water. Indeed, in several samples the amount of this constituent reached so high as nearly 30 per cent. Nothing is easier than the incorporation of water with salt butter. The butter is melted, and whilst cooling the salt and water are added, and the mixture kept constantly stirred until quite cold. In this way nearly 50 per cent. of water may be added to butter; but of course the quality of the article will be of the very worst kind.

A correspondent of the Lancet states that, on awakening about three o'clock in the morning at the house in which he was lodging, he perceived a light below the door of his room; and apprehending a fire, he hurried down stairs, and was not a little surprised to discover the whole family engaged in manipulating butter. He was informed in a jocose way that they were making Epping butter! For this purpose they used inferior Irish butter, which, by repeated washings, was freed from its excessive amount of salt; after which it was frequently bathed in sweet milk, the addition of a little sugar being the concluding stroke in the process. This "sweet fresh butter from Epping" was sold at a profit of 100 per cent. Our dairy farmers might take a hint from this anecdote. Does it not prove that the mere removal of the salt added to Irish butter doubles the value of the article?

It is as necessary to pay attention to the packing of butter as it is to its salting. If old firkins be employed, great care should be taken in cleaning them, and if the staves be loose, the firkins should be steeped in hot water, in order to cause the wood to swell, and thereby to bring the edges of the staves into close contact. New firkins often communicate a disagreeable odour to the butter. In order to guard against this, it is the practice in many parts to fill the firkins with very moist garden mould, which, after the lapse of a few days, is thrown out, and the firkin thoroughly scrubbed with hot water, rinsed with the same fluid in a cold state, and finally rubbed with salt, just before being used.

In packing the butter, the chief object to be kept in view is the exclusion of air. In order to accomplish this, the lumps of butter should be pressed firmly together, and also against the bottom and sides of the vessel. When the products of several churnings are placed in the same firkin, the surface of each churning should be furrowed, so that the next layer may be mixed with it. A firkin should never be filled in a single operation. About six inches of butter of each churning will be quite sufficient, and in a large dairy two or more firkins can be gradually but simultaneously filled. I strongly recommend the removal of the pickle jar from the dairy. When the layers of butter have been carried up to within an inch or so of the top of the firkin, the space between the surface of the butter and the edge of the vessel should be filled with fine dry salt, instead of pickle. A common mistake made is the holding over for too long a time of the butter: the sooner this article can be disposed of the better, for it never improves by age.

* * * * *

[Footnote 23: From two Greek words, signifying odour and soup.]

[Footnote 24: "A New Inquiry, fully illustrated by coloured engravings of the heart, lungs, &c., of the Diseased Prize Cattle lately exhibited at the Smithfield Cattle Club, 1857." By Frederick James Gant, M.R.C.S. London, 1858.]

[Footnote 25: Professor John Wilson's Report of the Agricultural Exhibition, Aarhuus, 1867.]



PART V.

ON THE COMPOSITION AND NUTRITIVE VALUE OF VEGETABLE FOODS.

SECTION I.

THE MONEY VALUE OF FOOD SUBSTANCES.

The flesh-forming principles of food are, as I have already stated, almost identical with the principal nitrogenous constituents of animals. Unlike the non-plastic substances, they are convertible into each other with little, if any, loss either of matter or of force. Not many years since it was the fashion to estimate the nutritive value of a food-substance by its proportion of nitrogen; but this method—not yet quite abandoned—was based on erroneous views, and yielded results very far from the truth. No doubt all the more concentrated and valuable kinds of food are rich in nitrogenous principles; but there are other varieties, the nutritive value of which is very low, and yet their proportion of nitrogen is very high. This point requires explanation. Both the plastic and the non-plastic materials of food exist in two distinct states—in one of which they are easily digestible, and in the other either altogether unassimilable or so nearly so as to be almost useless. Thus, for example, the cellular tissue of plants, when newly formed, is to a great extent digestible, whilst the old woody fibre is nearly, if not quite, incapable of assimilation. Gelatine, which in raw bones is easily digested in the stomachs of the carnivora, loses a large proportion of its nutritive value on being subjected to the action of steam. Again, a portion of the nitrogen of young succulent plants is in a form not sufficiently organic to admit of its being assimilated to the animal body. But, independently of these strong objections to the method of estimating the nutritive value of food by its per-centage of flesh-formers, there are many other reasons which as clearly prove the fallacy of this rule. If we were, for instance, to estimate the value of albumen according to the tables of food equivalents which were constructed some years ago by Boussingault and other chemists, we would find one pound weight of it to be equivalent to four pounds weight of oil-cake, or to twelve pounds weight of hay; yet, it is a fact that a horse would speedily die if confined to a purely albuminous diet, whereas hay is capable of supporting the animal's life for an indefinite period.

It is clear, then, from what I have stated, that neither the amount of flesh-formers, nor of fat-formers, contained in a given quantity of a substance is a measure of its nutritive value; nevertheless it would be incorrect to infer from this that the numerous analyses of feeding substances which have been made are valueless. On the contrary, I am disposed to believe that the composition of these substances, when correctly stated by the chemist, enables the physiologist to determine pretty accurately their relative alimentary value. Theory is certainly against the assumption that food is valuable in proportion to its content of nitrogen; nor has practice less strongly disproved its truth. An illustration drawn from the nutrition of plants will make this matter more apparent. Every intelligent agriculturist knows that guano contains nitrogen and phosphoric acid; both substances are indispensable to the development of plants, and therefore it would be incorrect to estimate the manurial value of the guano in proportion to the quantity of nitrogen it was capable of yielding. If the value of manures were determined only by their per-centage of nitrogen—a mode by which certain chemists still estimate the nutritive value of food—then woollen rags would be worth more than bones, and bones would be more valuable than superphosphate of lime. The truth is, that the analysis of feeding stuffs and manures is sometimes of little value if the condition in which the constituents of these substances exist be undetermined. For example, the analysis of one manure may show it to contain 40 per cent. of phosphate of lime, and three per cent. of ammonia, whilst, according to analysis, another fertiliser may include 20 per cent. of phosphate of lime, and two per cent. of ammonia. Viewed by this light solely, the first manure would be considered the more valuable of the two, whereas it might, in reality, be very much inferior. If the phosphate of lime in the manure, containing 40 per cent. of that body, were derived from coprolites or apatite, and its ammonia from horns, the former would be worth little or nothing, and the latter, by reason of its exceedingly slow evolution from the horns, would possess a very low value. If, on the contrary, the phosphate of lime, in the manure comparatively poor in phosphate, were a constituent of bones, and its ammonia ready formed (say as sulphate of ammonia), then, its value, both commercial and manurial, would be far greater than the other.

In estimating the money value of an article of food, we should omit such considerations as the relative adjustment of its flesh-formers and fat-formers, and its suitability to particular kinds of animals, as well as to animals in a certain stage of development. The manure supplied to plants contains several elements indispensable to vegetable nutrition; and, although the agriculturist most commonly purchases all these elements combined in the one article, still he frequently buys each ingredient separately. Ammonia is one of these principles, and, whether it be bought per se, or as a constituent of a compound manure, the price it commands is invariable. This principle should prevail in the purchase of food: each constituent of which should have a certain value placed upon it; and the sums of all the values of the constituents would then be the value of the article of food taken as a whole. There are, no doubt, practical difficulties in the way which prevent this method of valuation from giving more than approximatively correct results; but are there not precisely similar difficulties in the way of the correct estimation of the value of a manure according to its analysis? There are several constituents of food, the money value of which is easily determinable: these are sugar, starch, and fat. No matter what substance they are found in, the nutritive value of each varies only within very narrow limits. The value of cellulose and woody fibre is not so easily ascertained, as it varies with the age and nature of the vegetable structure in which these principles occur. There is little doubt but that the cellulose and fibre of young grass, clover, and other succulent plants, are, for the most part, digestible; and we should not be far astray if we were to assume that four pounds weight of soft fibre and cellulose are equivalent to three pounds weight of starch. As to old hard fibre, we are not in a position to say whether or not it possesses any nutrimental value worth taking into account. The estimation of the value of the flesh-forming materials is far more difficult than that of sugar, starch, pectine compounds, and fat. The nitrogenous constituents of food must be in a highly elaborated state before they are capable of being assimilated. In seeds—in which vegetable substances attain their highest degree of development—they probably exist in the most digestible form, whilst much of the nitrogen found in the stems and leaves of succulent plants, is either in a purely mineral state, or in so low a degree of elaboration as to be unavailable for the purpose of nutrition. But even plastic materials, in a high degree of organisation, present many points of difference, which greatly affect their relative alimental value; for example, many of them are naturally associated with substances possessing a disagreeable flavor: and as their separation from these substances is often practically impossible, the animal that consumes both will not assimilate the plastic matters so well as if they were endowed with a pleasant flavor. In seeds and other perfectly matured vegetable structures, the flesh-formers may exist in different degrees of availability. The nitrogen of the testa, or covering of the seeds, will hardly be so assimilable as that which exists in their cotyledons. The solubility of the flesh-formers—provided they be highly elaborated—is a very good criterion of their nutritive power. In linseed the muscle-forming substances are more soluble than in linseed-cake—the heat which is generally employed in the extraction of oil from linseed rendering the plastic materials of the resultant cake less soluble, and diminishing thereby their digestibility, as practice has proved.

From the considerations which I have now entered into, it is obvious that the chemical analysis of food substances as generally performed, though of great utility, does not afford strictly accurate information as to their commercial value, and still less reliable in relation to their nutritive power. At the same time, they as clearly establish the feasibility of analyses being made whereby the money value of feeding-stuffs may be estimated with tolerable exactitude. Let the chemist determine the presence and relative amounts of the ingredients of food-substances, and—if it be possible so to do with a degree of exactness that would render the results useful—place on each a money value. This done, let the physiologist and the feeder combine the food in such proportions as they may find best adapted to the nature, age, and condition of the animal to be fed.

It is to be regretted that the market price of feeding stuffs is not, in consequence of our defective knowledge, strictly determined by their nutritive value, for if such were the case, the feeder would merely have to adapt each to the nature and condition of his stock. Even amongst practical men there prevails, unfortunately, great diversity of opinion as to the relative nutritive value of the greater number of food substances; and I am quite certain that many of these command higher prices than others which in no respect are inferior. It would lead me too far from my immediate subject were I to enter minutely into the consideration of such questions as—whether an acre of grass yields more or less nutriment than an acre of turnips? I shall merely describe the composition and properties of grass and of turnips, and of the various other important food substances, and compare their nutritive power, so far as comparisons are admissible; but I shall say but little on the subject of the various economic and other conditions which affect the production of forage plants. When I shall have described the chemical nature and physical condition of the various articles of food, and the results of actual feeding experiments made with them, the feeder will then be in a position to determine which are the most economical to produce or to purchase.

SECTION II.

PROXIMATE CONSTITUENTS OF VEGETABLES.

The saccharine, or amylaceous substances constitute the most abundant of the proximate constituents of plants. They are composed of carbon, hydrogen, and oxygen. I shall briefly describe the more important members of this group of substances, namely, starch, sugar, inulin, gum, pectin, and cellulose.

Starch, or fecula, occurs largely in dicotyledonous seeds, peas, &c., and still more abundantly in certain monocotyledonous seeds, such as wheat and barley. It constitutes the great bulk of many tubers and roots—for example, the potato and tapioca. It consists of flattened ovate granules, which vary in size according to the plant. In the beetroot they are 1/3500 of an inch in diameter, whilst in tous les mois they are nearly 1/200 of an inch in diameter. Most of the starch granules are marked by a series of concentric rings. Starch is heavier than water, and is insoluble in that fluid when cold; neither is it dissolved by alcohol or ether. When heated in water having a temperature of at least 140 deg. Fahrenheit, it increases greatly in volume, and acquires a gelatinous consistence. When the water is allowed to cool, a portion of the starch becomes insoluble, whilst another portion remains in solution; the latter form of starch is sometimes termed amidin, from the French word for starch, amidon. When dry starch is heated to 400 deg. Fahr., it is converted, without any change in its composition, into a soluble gum-like substance, termed dextrin, or British gum. On being boiled in diluted sulphuric acid it is converted into a kind of sugar; and the same effect is produced by fermentation—for example, in the germination of seeds. Fresh rice contains 82, wheat 60, and potatoes 20 per cent. of starch. This substance constitutes a nutritious and easily digestible food, but alone cannot support life. Arrowroot is only a pure form of starch.

Sugar occurs less abundantly in plants than starch. There are several varieties of this substance, of which the kinds termed cane sugar (sucrose) and grape sugar (glucose), are only of importance to agriculturists. The former enters largely into the composition of the sugar-cane, the beetroot, the sugar-maple, the sorgho grass, pumpkins, carrots, and a great variety of other plants. Grape sugar is found in fruits, especially when dried—raisins and figs—in malted corn, and in honey. In the sugar-cane there is 18 per cent., and in the beetroot 10 per cent. of sugar.

Cane sugar, when pure, consists of minute transparent crystals. It is 1-6/10 heavier than water, and is soluble in one-third of its weight of that fluid. By long-continued boiling in water it is changed into uncrystallizable sugar, or treacle, by which its flavor is altered, but its sweetening power increased.

Grape sugar crystallizes in very small cubes, of inferior color as compared with cane sugar crystals. It dissolves in its own weight of water, being three times less soluble than sucrose. In sweetening power one part of cane sugar is equal to 2-1/2 parts of grape sugar; but there is probably little if any difference, between the nutritive power of the two substances.

Inulin is a substance somewhat resembling starch. It does not occur in large quantities. It is met with in the roots of the dandelion, chicory, and many other plants.

Gum is an abundant constituent of plants. The kind termed gum arabic, so largely employed in the arts, is a very pure variety of this substance. Common gums are said to be essentially composed of a very weak acid—gummic, or arabic acid—united with lime and potash. The solution of gum is very slightly acid, and has a mucilaginous, ropy consistence: it is almost tasteless. Mucilage, or bassorin, is simply a modified form of gum, which, though insoluble in water, forms a gelatinous mixture with that fluid. It exudes from certain trees—the cherry for example—and exists largely in linseed and other seeds. Gums are nutritious foods, but it is probable that they are not equal in alimental power to equal weights of starch or sugar.

Vegetable jelly, or pectin, is almost universally diffused throughout the vegetable kingdom. It is owing to its presence that the juices of many fruits and roots possess the property of gelatinizing. It is soluble in water, but prolonged boiling destroys its viscous property. Pectose is a modification of pectin; it is insoluble in water. According to Fremy, the hardness of green fruits is due to the presence of pectose; which is also found in the cellular tissue of turnips, carrots, and various other roots.

Cellulose is a fibrous or cellular tissue, allied in composition to starch. It is the most abundant constituent of plants, and forms the very ground-work of the vegetable mechanism. Linen, cotton, and the pith of the elder and other trees are nearly pure forms of cellulose. Ligneous, or woody tissue (lignin) is indurated cellulose, hardened by age. It is almost identical in composition with cellulose. Pure cellulose is white, colorless, tasteless, insoluble in water, oil, alcohol, or ether. It is heavier than water. Sulphuric acid is capable of converting it into grape, or starch sugar. In its fresh and succulent state cellulose is digestible and nutritious; but in the form of ligneous tissue it opposes a very great resistance to the action of the digestive fluids. Digestible cellulose is probably equal in nutritive power to starch.

Oils and fats occur abundantly in vegetables, more particularly in their seeds. In the seeds of many cruciferous plants the proportion of fat and oil exceeds 35 per cent. The oils and fats termed fixed are those which possess the greatest interest to agriculturists; the volatile oils being those which confer on certain plants their fragrant odour. There are a great variety of vegetable oils, but the proximate constituents of most of them are chiefly stearin, margarin, olein, and palmitin.

Stearin is a white crystalline substance, sparingly soluble in alcohol and ether, but insoluble in water. There are two or three modifications of this substance, but they do not essentially differ from each other. The melting point varies from 130 deg. to 160 deg. Fahr. Stearin is the most abundant of the fats.

Margarin presents the appearance of pearly scales. It is the solid fat present in olive oil, and it is also met with in a great variety of fats and oils. It melts at 116 deg. Fahr.

Olein is the fluid constituent of oils and fatty substances. It resists an extreme degree of cold, without solidifying. There are several modifications of this body—the olein of olive oil being somewhat different from that of castor oil; the olein of linseed is sometimes termed linolien.

Palmitin.—This fat occurs in many plants, but as it makes up the great bulk of palm oil, it has been termed palmitin. It is white, and may be obtained in feathery-like masses. Its melting point varies from 114 deg. to 145 deg., there being, according to Duffy, three modifications of this substance.

The fats and oils are lighter than water. They contain far more carbon and hydrogen, and less oxygen, than are found in the sugars and starches. They all consist of acids (stearic, palmitic, &c.) united with glycerine. On being boiled with potash or soda, the latter take the place of the glycerine, which is set free, and a soap is produced. The fatty acids strongly resemble the fats. In nutritive power, one part of fat is equal to 2-1/2 parts of starch or sugar.

The Albuminous substances contain, in addition to the elements found in starch, nitrogen, sulphur, and phosphorus. Albumen, fibrin, and legumin constitute the three important members of the "Nitrogenous" constituents of plants.

Albumen is an uncrystallizable substance. It is soluble in water, unless when heated to 140 deg. Fahr., at which temperature it coagulates, i.e., becomes solid and insoluble. The gluten of wheat is composed chiefly of albumen, and of bodies closely allied to that substance.

Fibrin, when dried, is a hard, horny, yellow, solid body. It contains a little more oxygen than is found in albumen. This substance is best known as a constituent of animals, and it does not appear to be abundant in plants. The portion of the gluten of wheat-flour, which is insoluble in boiling alcohol, is considered by Liebig and Dumas to be coagulated fibrin.

In the seeds of leguminous and a few other kinds of plants large quantities of a substance termed legumin are found. It resembles the casein, or cheesy ingredient of milk; indeed, some chemists consider it to be identical in composition with that substance. When pure, it is pearly white, insoluble in boiling water, but soluble in cold water and in vinegar. The saline matters found in plants are always associated with the albuminous bodies; the latter, therefore, form the bones as well as the muscles of animals.

A great many substances are found in plants, such as wax, mannite, "extractive matter," citric, malic, and other acids, of the nutritive value of which very little is known. The substances described in this section constitute, however, at least 95 per cent. of the weight of the vegetable matters used as food by live stock.

SECTION III.

GREEN FOOD.

The Grasses.—More than one-half the area of Great Britain and Ireland is under pasture; the grasses, therefore, constitute the most important and abundant food used by live stock. The composition of the natural and artificial grasses is greatly influenced by the nature of the soil on which they are grown, and by the climatic conditions under which they are developed. Many of them are almost worthless, whilst others possess a high nutritive value. Amongst the most useful natural grasses may be enumerated Italian rye-grass, Meadow barley, Annual Meadow-grass, Crested dogstail-grass, Cocksfoot-grass, Timothy or Meadow catstail-grass, and Sweet vernal-grass. Amongst grasses of medium quality I may mention common Oatlike-grass, Meadow foxtail grass, Smooth and rough stalked Meadow-grass, and Waterwhorl-grass. There are very many grasses which are almost completely innutritious, and which ought, under no circumstances, to be tolerated, although too often they make up the great bulk of the herbage of badly-managed meadows and pastures. Such grasses are, the Meadow soft-grass, Creeping soft-grass, False brome-grass, and Upright brome-grass. The rough-stalked Meadow-grass, though spoken favorably of by some farmers, is hardly worthy of cultivation, and the same may be said of many of the grasses which have a place in our meadows and pastures. (See "Analyses of Natural Grasses in a Fresh State, by Dr. Voelcker," on next page.)

The Schraeder brome is a perennial lately introduced into France. It is described as an exceedingly valuable forage crop, and one which is admirably adapted for the feeding of dairy cows. It would be desirable to give it a trial in these countries. The composition (which is very peculiar) of this plant is stated to be as follows, when dry:—

ANALYSIS OF SCHRAEDER BROME HAY.

Water 16.281 Nitrogenous matters 23.443 Fat 3.338 Starch gum, &c. 22.549 Cellulose (fibre) 19.843 Ashes 14.546 ———- Total 100.000

ANALYSES OF NATURAL GRASSES IN A FRESH STATE, BY DR. VOELCKER.

+ -+ KEY: A. Water. B. Albuminous or Flesh-forming Principles. C. Fatty Matters. D. Respiratory Principles: Starch, Gum, Sugar. E. Woody Fibre. F. Mineral Matter or Ash. G. Date of Collection. + -+ -+ -+ -+ + + -+ -+ A. B. C. D. E. F. G. + -+ -+ -+ -+ + + -+ -+ Anthoxanthum odoratum Sweet-scented vernal grass 80.35 2.00 .67 8.54 7.15 1.24 May 25 Alopecurus pratensis Meadow foxtail grass 80.20 2.44 .52 8.59 6.70 1.55 June 1 Arrhenatherum avenaceum Common oat-like grass 72.65 3.54 .87 11.21 9.37 2.36 July 17 Avena flavescens Yellow oat-like grass 60.40 2.96 1.04 18.66 14.22 2.72 June 29 Avena pubescens Downy oat-grass 61.50 3.07 .92 19.16 13.34 2.01 July 11 Briza media Common quaking grass 51.85 2.93 1.45 22.60 17.00 4.17 June 29 Bromus erectus Upright brome grass 59.57 3.78 1.35 33.19 2.11 " 23 Bromus mollis Soft brome grass 76.62 4.05 .47 9.04 8.46 1.36 May 8 Cynosurus cristatus Crested dogstail grass 62.73 4.13 1.32 19.64 9.80 2.38 June 21 Dactylus glomerata Cocksfoot grass 70.00 4.06 .94 13.30 10.11 1.54 " 13 Ditto, seeds ripe 52.57 10.93 .74 12.61 20.54 2.61 July 19 Festuca duriuscula Hard fescue grass 69.33 3.70 1.02 12.46 11.83 1.66 June 13 Holcus lanatus Soft meadow grass 69.70 3.49 1.02 11.92 11.94 1.93 " 29 Hordeum pratense Meadow barley 58.85 4.59 .94 20.05 13.03 2.54 July 11 Lolium perenne Darnel grass 71.43 3.37 .91 12.08 10.06 2.15 June 8 Lolium italicum Italian rye-grass 75.61 2.45 .80 14.11 4.82 2.21 " 13 Phleum pratense Meadow catstail grass 57.21 4.86 1.50 22.85 11.32 2.26 Poa annua Annual meadow grass 79.14 2.47 .71 10.79 6.30 .59 May 28 Poa pratensis Smooth-stalked meadow grass 67.14 3.41 .86 14.15 12.49 1.95 June 11 Poa trivialis Rough-stalked ditto 73.60 2.58 .97 10.54 10.11 2.20 " 18 Grass from water meadow 87.58 3.22 .81 3.98 3.13 1.28 Apr. 30 Ditto, second crop 74.53 2.78 .52 11.17 8.76 2.24 June 26 Annual rye-grass 69.00 2.96 .69 12.89 12.47 1.99 " 8 + -+ -+ -+ -+ + + -+ -+

Most of the grasses here mentioned were analysed when in flower.

Tussac Grass (Dactylis caespitus) is recommended as an excellent plant to grow on very poor, wet, or mossy soils.[26] It is an evergreen grass, somewhat resembling coltsfoot. It is relished by cattle.

ANALYSIS OF TUSSAC GRASS BY JOHNSTONE.

Lower part. Upper part.

Water 86.09 75.17 Flesh-formers 2.47 4.79 Sugar, gum, &c. 4.62 6.81 Woody fibre (with a little albumen) 5.68 11.86 Ash 1.14 1.37 ——— ——— Total 100.00 100.00

The "artificial grasses" embrace the clovers, vetches, lucerne, and a few other plants, some of which are seldom cultivated.

ANALYSES OF DIFFERENT KINDS OF CLOVER, BY DR. ANDERSON.

+ - KEY: A. Water. B. Dry Substances. C. Ash. D. Nitrogenised Substances. E. Ash. F. Nitrogenised Matters. + -+ - Per-centage in the Per-centage Fresh Clover. in Dry Clover. + -+ -+ + + -+ - A. B. C. D. E. F. + -+ -+ + + -+ - Red clover Trifolium pratense: 1. From English seed 85.30 14.70 1.30 2.31 8.90 15.87 2. From German seed (from the Rhine) 81.68 18.32 1.49 2.81 8.15 15.50 3. From French seed 83.51 16.49 1.95 2.25 11.82 13.56 4. From American seed 79.98 21.02 1.58 2.87 8.05 ... 5. From Dutch seed ... ... ... ... 8.82 12.43 Cowgrass Trifolium medium:[27] Variety, " Duke of Norfolk 77.39 22.61 2.73 2.25 12.09 10.19 " common 81.76 18.24 1.92 3.19 10.53 14.37 Crimson clover, Trifolium incarnatum: From French seed 82.56 17.44 1.88 3.25 10.81 18.56 Yellow clover Medicago lupulina: From English seed 77.38 22.62 2.02 3.50 8.95 15.44 From French seed 78.60 21.40 1.75 2.94 8.18 13.69 + -+ -+ + + -+ -

Clover is very rich in flesh-forming and heat-producing substances. There are several varieties of this plant, of which the Alsike Clover appears to be the most valuable, as it contains a high proportion of organic matter and gives the largest acreable produce. The nature of the soil influences, to a great extent, the composition of this plant: this no doubt accounts for the somewhat discrepant result of the analyses of it made by Way, Voelcker, and Anderson.

The composition of the Vetch, Sainfoin, and Lucerne, resembles very closely that of the Clover: indeed, it appears to me that all these leguminous plants are nearly equally valuable as green forage, but that the best adapted for hay is the Clover. In the following table the composition of these plants is shown:—

ANALYSES OF CLOVER, BY DR. VOELCKER.

- - - - -+ - I. II. III. IV. V. Red White Yellow Alsike. Bokhara Clover. Clover. Clover. Clover. Clover. + - - - - - Water 80.64 83.65 77.57 76.67 81.30 Soluble in Water a. Organic substances 6.35 4.98 8.26 4.91 6.80 b. Inorganic substances 1.55 1.13 1.40 1.33 1.54 Insoluble in water a. Impure vegetable fibre 11.04 9.80 12.17 16.36 10.01 b. Inorganic matters (ash) 0.42 0.44 0.60 0.73 0.35 - - - - - 100.00 100.00 100.00 100.00 100.00 - - - - - -

ANALYSES OF LUCERNE, SAINFOIN, AND VETCH.

- -+ I. II. III. Lucerne. Sainfoin. Vetch. + - Water 73.41 77.32 82.16 Soluble in Water a. Organic substances 9.43 8.00 6.07 b. Inorganic substances 2.33 1.20 1.07 Insoluble in water a. Impure vegetable fibre 14.08 12.95 10.23 b. Inorganic matters (ash) 0.75 0.53 0.47 - 100.00 100.00 100.00 - -

The artificial grasses are, on the whole, more nutritious than the natural grasses; but I should explain that the analyses of the natural grasses which I have quoted refer to those plants in what may be almost termed their wild state: under the influence of good cultivation—when irrigated or top-dressed with abundance of appropriate manure—their analyses would indicate a higher nutritive value. The grasses, and more especially the so-called artificial grasses, are more nutritious and digestible when young. In old clover the proportion of insoluble woody fibre is often so considerable as to greatly detract from the alimental value of the plant.

The Lentils, the Birdsfoot, the Trefoil, and the Melilot are leguminous plants which occasionally are found as constituents of forage crops. Lentils are extensively cultivated on the Continent, and are the only kind of these plants the chemistry of which has been at all studied. The straw contains 7 per cent. of flesh-formers.

The Yellow Lupine is cultivated rather extensively in Germany, France, and Belgium, partly for feeding purposes, partly to furnish a green manure. Its seeds constitute a nutritious article of food for man, and its stems and leaves are given to cattle. An attempt was made a few years ago to introduce its cultivation, as a field crop, into England, and very satisfactory results attended the first trials made with it. Mr. Kimber, who has cultivated this crop, states that it is likely to prove valuable on light sandy soils, where the ordinary green fodder crops are not easily cultivated. The produce per acre obtained in Mr. Kimber's trial was about nineteen tons. Cattle and sheep relish the Yellow Lupine, but according to Mr. Kimber, pigs reject it. Professor Voelcker examined this plant, and found that it resembled in composition the ordinary artificial grasses, except in one respect, namely, a remarkable deficiency in sugar. Altogether, it is not so rich in nutriment as any of the commonly cultivated leguminous plants; but as it can be cultivated on a very poor soil, and gives a good return, it is probable that the Yellow Lupine will yet become a common crop in Britain. The following table exhibits the results of Dr. Voelcker's analysis.

COMPOSITION OF YELLOW LUPINES (CUT DOWN IN A GREEN STATE).

In natural state. Dried at 212 deg.F.

Water 89.20 Oil .37 3.42 [*] Soluble albuminous compounds 1.37 12.68 Soluble mineral (saline) substances .61 5.64 [] Insoluble albuminous compounds 1.01 9.35 Sugar, gum, bitter extractive matter, and digestible fibre 3.96 36.68 Indigestible woody fibre (cellulose) 3.29 30.48 Insoluble mineral matters .19 1.75 ——— ——— 100.00 100.00 [* Containing nitrogen .22 2.03] [ Containing nitrogen .16 1.48]

Rib grass plantain (Plantago lanceolata) is one of those plants, the value of which for forage purposes is questionable. Many persons believe it to be a useful food. Its composition, which looks favorable, is as follows:—

Water 84.78 Albuminous matters 2.18 Fatty matters 0.56 Starch, gum, &c. 6.08 Woody fibre 5.10 Mineral matter 1.30

The grasses, natural and artificial, are occasionally affected by a formidable and well-known fungus, the ergot. Italian rye-grass is the most liable to the ravages of this pest, and there are on record several cases in which ergotted rye-grass proved fatal to the animal fed upon it. Clover and the various leguminous plants appear more liable to the ergot disease than the natural grasses (except rye-grass), but I have on several occasions noticed this fungus on the spikelets of Hordeum pratense, Festuca pratense, and Bromus erectus. It has also been noticed that rye-grass rapidly developed under the influence of liquid manure is so rank that young animals fed upon it are poisonously affected. Alderman Mechi states that in July, 1864, ten out of his thirty Shorthorn calves died in consequence of eating the heads of Italian rye-grass, and that the survivors' health was seriously injured. He was also unfortunate with his lambs, which, during the same month, were folded on Italian rye-grass. "Four days ago," writes the Alderman, "it was sewaged, having been prior to the former growth also guanoed. In four days it had grown from four to five inches, was of an intense green, and pronounced to be, by sharp practical men, just the food for lambs. Well, we put on our lambs, taking care to do so in the evenings after they had been well fed. My bailiff accompanied them, and, within five minutes, turning accidentally round, he saw two of the lambs with their heads in the air staggering (stomach staggers it is called) and frothing at the mouth. He immediately saw the mischief, removed the lambs, and on their way back to a bare fold some of them vomited the Italian rye-grass that they had just eaten, accompanied by frothy slime; others brought it up during the night. Some of them trembled, gaped, and showed all the same symptoms that my calves had done, such as rapid pulse, &c. Two or three of them are rather queer to-day. I hope that Professor Simmonds or some capable person will tell us how this is? If we mow this grass, bring it home, and cut it into chaff, all which tends to heat or dry it, it becomes wholesome food. The same remarks apply in degree to very succulent tares. If the Italian grass is brought home and given long and quite fresh to the calves, it will kill them. It does not appear to injure old ewes as it does lambs or shearlings. The dry weather has something to do with it. In wet weather the evil is much diminished, or disappears."

It is probable that the juice of this poisonous herbage was extremely rich in matters only semi-organised, and perhaps abounded in the crude substances from which the vegetable tissues are elaborated. Such rank grass as this was should not be used until it has attained to a tolerably developed state: in mature plants the juices contain more highly organised matters than are found in young vegetables.

The Sorghuo, or Holcus Saccharatus.—This plant, introduced to the notice of the British farmer but a few years ago, is only grown in these countries in small quantities. It is very rich in sugar, and cattle relish it greatly. Its composition, according to Dr. Voelcker, is as follows:—

Water 81.80 Albuminous matters 1.53 Insoluble ditto 0.66 Sugar 5.85 Wax and fatty matter 2.55 Mucilage, pectin, and digestible matters 2.59 Indigestible woody fibre 4.03 Mineral matter 0.99 ——— 100.00

The plants referred to in the above analysis were cut in September. It is found that the composition of the plant is very different at different seasons.

Green Rye is employed as a forage crop, for which purpose it is well adapted. It is about equal in nutritive power to clover. According to Dr. Voelcker its composition is as follows:—

Water 75.423 Flesh-formers 2.705 Fatty matter 0.892 Gum, pectin, sugar, &c. 9.134 Woody-fibre 10.488 Mineral matter 1.358 ———- 100.000

Buckwheat is occasionally cut in a green state and used as food for stock. Its composition, according to Einhof and Crome, is as follows:—

Water 82.5 Nitrogenous compounds 0.2 Extractive matters 2.6 Starch, &c. 4.7 Cellulose 10.0 ——- 100.0

Rape is one of our most valuable plants for stock feeding. Two varieties are cultivated in these countries—the summer rape (Brassica Campestris oleifera) and winter rape (Brassica rapus). The great utility of rape arises from the circumstance of its being generally obtained as a stolen crop; for otherwise it is not quite equal to other plants that might be substituted for it—cabbages, &c. This plant is very rich in oily matters, and has been found well adapted both for the feeding of cattle and the fattening of sheep. Its composition, according to Voelcker, is shown in this table:—

COMPOSITION OF GREEN RAPE.

Water 87.050 Flesh-formers 3.133 Fatty matters 0.649 Other respiratory substances 4.000 Woody fibre 3.560 Mineral matter (ash) 1.608 ———- 100.000

With respect to the value of rape for the feeding of stock in spring, Mr. Rham makes the following remarks:—

If the crop is very forward it may be slightly fed off, but in general it is best to let it remain untouched till spring. In the end of March and the beginning of April it will be a great help to the ewes and lambs. It will produce excellent food till it begins to be in flower, when it should immediately be ploughed up. The ground will be found greatly recruited by this crop, which has taken nothing from it, and has added much by the dung and urine of the sheep. Whatever be the succeeding crop, it cannot fail to be productive; and if the land is not clean, the farmer must have neglected the double opportunity of destroying weeds in the preceding summer, and in the early part of spring. If the rape is fed off in time, it may be succeeded by barley or oats, with clover or grass seeds, or potatoes, if the soil is not too wet. Thus no crop will be lost, and the rape will have been a clear addition to the produce of the land. Any crop which is taken off the land in a green state, especially if it be fed off with sheep, may be repeated without risk of failure, provided the land be properly tilled; but where cole or rape have produced seed, they cannot be profitably sown in less than five or six years after on the same land. The cultivation of rape or cole for spring food cannot be too strongly recommended to the farmers of heavy clay soils.

The Mustard Plant is occasionally used as food for sheep, for which purpose its composition shows it to be well adapted. Voelcker's analysis proves it to be very rich, relatively, in muscle-forming elements and in mineral matters; it might, therefore be with advantage combined with food relatively deficient in these principles.

COMPOSITION OF FRESH MUSTARD.

Water 86.30 Albuminous matters 2.87 Non-nitrogenous matters (gum, sugar, oil, &c.) 4.40 Woody fibre 4.39 Ash 2.04 ——— 100.00

The Prickly Comfrey has been recommended as a good forage plant. It yields an abundant crop—or rather crops, for it may be cut several times in the year. The plant is a handsome one, and it might combine the useful with the ornamental if it were cultivated on demesne or villa farms. Dr. Voelcker states its composition to be as follows:—

Water 88.400 Flesh-forming substances 2.712 Heat and fat-producing matters 6.898 Ash 1.990 ———- 100.000

Chicory is used as a forage crop on the Continent, and Professor John Wilson surmises that it may yet be generally cultivated for this purpose in Great Britain. At present it is rarely grown except for the sake of its roots, which are used as partial substitutes for, or adulterants of, coffee.

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