blood supplies carbon to the lungs for keeping up the animal heat, with fat and oily fluids deposited in the softer tissues, as well as in the very substances of the bones themselves, as a store from which nature can extract a due supply when necessity compels her; lastly, the blood is the true moving power by which the whole animal machine is put into motion, just as steam is to the steam engine, and coals as fuel to the fire. As far as I have proceeded I have only spoken of that part of the food from which animal flesh is naturally formed; i. e., the gluten extracted from the vegetable, the albumen, and the casein. My self imposed task, however, is not yet complete. I have now to take into consideration the offices which are fulfilled by the sugar, starch, gum, oil, or fat, which we find, by examination, constitute so large a proportion of the food of man and the principal of the lower orders of animals. Now, we find from observation that every animal has a temperature above that of the surrounding atmosphere; and physiologists have denominated it the animal heat, which, in those animals domesticated by man, is found to be, on an average, about 100 deg. of Fahrenheit's thermometer; in man it is about 70 deg., and we find that it continues much the same under every kind of circumstance, whether we live beneath a tropical sun, a more temperate region, or the frozen climes of the North. The animal heart originates in the body; it is created by the chemical combination, or, if I may employ the term, the combustion of the elements which enter into the formation of starch, with the other nonnitrogenous constituent particles of the food, united with the oxygen of the air, which is received into the lungs during the function of inspiration; and likewise by a portion that is absorbed through the skin. Upon examining the atmospheric air which we breathe, we find, upon submitting it to a chemical analysis, that it is composed of twenty-one parts of nitrogen, with so small a quantity of carbonic acid gas that its amount cannot be calculated in a given quantity of air; yet of course an immense proportion must exist, for it is supposed that the atmosphere extends forty-five miles at least in height, and presses at the ratio of fifteen pounds upon every square inch. This was discovered by Torricelli and Galileo in the seventeenth century. However, when the air we have inspired has been expelled from the body, we find that it has undergone but little if any change; the oxygen, however, has disappeared, and been replaced by an equable quantity of carbonic acid gas, with a small quantity of aqueous vapor. The proportion of animal heat which attends this chemical change is consequent upon the amount of carbon and hydrogen which is consumed. The heat which is thus produced is occasioned by exactly the same chemical action as that which causes the combustion of wood in a stove, or the fat of a lamp or candle, and the products of which are exactly the same; the carbon and the hydrogen of the food combine with the oxygen that is supplied by the atmosphere, and heat is generated in the body in proportion to the quantity which is consumed. In the stove or lamp the same changes take place, the fuel being composed of similar elements entering into the composition of the food; and the results of the combustion are precisely the same, the combination being less energetic in the body than in the stove or lamp. Now, how is it in man? In a full-grown adult, if we take the weight of the carbon which is disengaged in the excretions from the weight of the carbon contained in the food that is consumed during the twenty four hours, we shall soon find that the remainder will amount to somewhere about fourteen ounces, and this is assimilated with the component parts of the body; the weight of which, however, does not increase, for it is a well-known philosophical axiom, that fourteen ounces of carbon will require thirty-seven ounces of oxygen for its transformation into carbonic acid, which passes off from the lungs and skin. Thus, in this simple manner, we can easily comprehend how it is that the enormous quantity of oxygen which is introduced into the animal body by the progress of inspiration, and the great proportion of carbon which is derived from the food consumed, are removed from the body; and, likewise, how it is that the food required for supporting the animal in its normal condition is in exact proportion to the quantity of oxygen that is absorbed. Now we find that a horse consumes daily, in his food, upon an average, eighty-nine ounces of pure carbon, and a cow seventy ounces; the former requires 212 ounces, the latter 186 ounces of oxygen, in order to transform the consumed carbon into carbonic acid. I have already stated that, in addition to the constituents which I have named, the vegetable is found, upon chemical analysis, to contain a small quantity of fatty matter in addition to the earthy and saline substances of which it is composed. The question is now to be answered, What are the purposes which they answer in the animal economy? Every animal that is in a state of sound health has a layer of fat, which is situated between the skin and the muscles, and likewise between the muscles themselves, by which means they have great freedom of motion. Fat is also deposited in the body of the animal, particularly in the neighporhood of the bowels, also attached to a portion of them, and enveloping the kidneys, (where it is vulgarly called by butchers the suet). In the carnivora, or flesh-eating animals, the fat which is contained in the food they eat is consumed in the lungs for the purpose of preserving the proper quantity of animal heat, and consequently in these creatures we but very rarely find the body of the carnivorous animal to contain much fat. M. Darwin, in his Journal of Researches into the natural history of the countries visited during the voyage of the Beagle, informs us that the Gauchos, or simple countrymen in the Pampas, South America, lived for months together upon flesh; but he observed that they ate large quantities of fat. And Dr. Richardson, in speaking of these people, has also remarked "that, when they have fed for a long time solely upon lean animal food, the desire for fat becomes so insatiable that they can consume a large quantity of unmixed and even oily fat without nausea. This instinc tive desire for fat in man and animals living on flesh arises from the imperative demands which are daily made upon the body for carbon to keep up the proper amount of animal heat, and which is contained in the fat that is consumed as an article of diet. Thus far in the omnivorous and carnivorous animals; but in the herbivorous creatures it is widely different. The supply to the lungs is derived from the starch, sugar, and gum in the vegetable, while the fat which exists in the food is in a great measure laid up as fat in the animal body; therefore it is that we find the bodies of herbivorous quadrupeds generally much fatter than the carnivora. But if the supply of the starch in the food is inadequate to the demands of respiration, then the elements * One ounce of oxygen equals 1,416.5 cubic inches. of the fat become consumed in the lungs, exactly as it is in the carnivorous animal; the sugar, gum, and starch become speedily transformed into aqueous vapor and carbonic acid in the animal system. These are the first consumed; and if this supply proves to be inadequate for the purpose required, then the fat, next the fat of the animal body, and, finally, the tissues themselves, are placed under contribution; the animal becoming thin, feeble, and emaciated, and ultimately dying from starvation. REDUCING THE FOOD OF CATTLE BEFORE GIVING IT. As I have just concluded the experiments you wished, I hasten to forward you the results, which are as follow: Two horses in good health, in daily work, and as nearly as possible equal in size and age, were selected for the experiment. They were each allowed 5 lbs. of oats, 42 lbs. per bushel, and a sufficiency of good hay, of which they consumed about 17 lbs. per diem each horse. The only difference in the feeding consisted in one horse having the oats thoroughly crushed, and the other being allowed the oats uncrushed. On the fourth day of the above mode of feeding the solid excrements of each horse were examined; 100 parts of the dung from the horse fed on crushed oats were found to be deprived of all the nutricious matter contained in the food, and to consist of woody fibre, mixed with the animal secretions and some salts; while 100 parts of the dung from the horse fed on uncrushed oats were found to contain one-quarter per cent. of nutritive matter, consisting of starch and gluten, which had not been acted on by the stomach, mixed with the ordinary constituents of the solid excrements of the animal-this arising from the inability of the horse to perform perfect mastication, and must vary with circumstances, such as age and rapidity of feeding. The same horses were then fed with cut and uncut food, consisting of hay cut into chaff and hay uncut. At the expiration of the third day the excrements were examined, but no chemical difference in their composition was detected; the food, in both instances, was found to be equally exhausted of its nutritive matter. The shorter period occupied by the horse in filling its stomach, and consequently greater amount of rest obtained, and the means of mixing food and preventing waste by cutting it into chaff, require no observation from me, but will be material points in this mode of feeding. A. GYDE. SHEEP. I received, a short time since, a copy of the printed Agricultural Circular issued from the Patent Office. Several points in the inquiries have attracted my attention, but I can only devote a leisure hour to a response to that relating to "sheep." The subject is so full of interest and so important, that a volume would be necessary to approach an adequate examination of the various topics it involves. I will attempt to compress in a small space some prominent considerations which are founded upon the experience and reflection of years. I think sheep husbandry in many sections of the country eminently profitable. The extent of this depends of course upon the scale in the prices of wool. A medium price now prevails, and in those districts appropriated to the purpose, few occupations to the farmer can be more attractive or remunerative. It should always be recollected, in forming an opinion on this subject, that lands of little value, and worthless for most agricultural purposes, are those best adapted to a summer range for sheep. Luxuriant pasturage is afforded to them by the scanty herbage that springs up in the fissures of the rocks and the gorges of mountain nooks, and by the briers and bushes which mantle their cliffs. Sheep range and fatten upon precipitous crags inaccessible to cattle and horses. Sandy plains are in the highest degree congenial to the health and habits of sheep. They are often relieved from epidemic and hereditary diseases, contracted in cold and moist pastures, when transferred to a range upon light, dry lands. They feed with great avidity upon the sprouts and bushes, the spontaneous products of sandy soils. This vegetation, and the rank and coarse herbage which infest these lands in their native condition, are extirpated by the sheep, and white clover rapidly introduced. This clover always indicates the presence of sheep, and is, perhaps, the most delicate and nutritious grass for pasturage. It springs early, and affords an early and enduring feed. It is of immense importance in the renovation and fertilizing of these lands. Its fibres spread gradually a massive net-work over the entire surface, that binds the soil together, protects it from the sun and winds, and affords, in tillage, a rich basis for agricultural operations. Neat cattle or horses would starve upon a tract of sandy soil where sheep will thrive and fatten, whilst they maintain the land in constant progression in value and fertility. The continual and gentle pressure of their feet consolidates, without penetrating, the earth. The light and diffused droppings of sheep fertilize the soil, when the copious excrements of larger animals destroy vegetation and rapidly deteriorate pastures by the introduction of coarse and worthless herbage. In my personal experience I have known pasture ranges occupied for dairies become, from this cause operating a few years, totally infested by bushes, johnswert, and other noxious weeds, and of little practical value. The introduction of sheep in two seasons has thoroughly subdued this rank vegetation and dotted the earth with a rich and delicate growth of nutritious clover. When the great value of sandy lands in sheep husbandry becomes understood, vast tracts of barren and desolate wastes, which are now unoccupied and deform our country, will be appropriated for sheep ranges, and with the most profitable results. The immense and beneficial influence of this system-not alone on the wool-growing interest, but upon the wealth and producing capital of the nation-can scarcely be appreciated. Each class of these lands, specially adapted to sheep, may now be purchased at almost a nominal price. Sheep will nearly maintain themselves during the winter whilst they have access to the earth, or good opportu nity of browsing, and uniformly long after other stock have demanded vigilant care and incurred heavy expense. They have been known to subsist in vigor and health an entire winter with no food or protection other than the boughs and limbs of the pine. They eat greedily, and are sufficiently nourished by the poorest hay mingled with ferns and bushes. A great proportion of the winter fodder of hardy sheep may consist of bean and pea straw, with other refuse of the barn. No animal known to the economy of our agriculture can be maintained with so much easo and so little expense. These remarks apply to this branch of husbandry when there is occupation of the lands I have underrated, which are peculiarly adapted to sheep. Low and damp loam or clay are not congenial to their health. Lands of great value, from their locality or productiveness in tillage, can more profitably be appropriated to other purposes. Another prominent fact must be regarded in an estimate of the advan tages of sheep husbandry. Horses, as they become aged, grow worthless. The ox and swine can only be prepared for the shambles with great toil and expenditure; but the sheep, when turned off at his maturity, is ready for market, with no other expense or charge than his ordinary pasturage. The summergrazing of sheep upon appropriate lands is a trifling consideration in calculating their disbursements. One ton of hay, under ordinary circumstances, will keep ten sheep through a winter in the meridian of New England. The average value of hay in that district is $8 per ton. The incidental expenses of the ten sheep, particularly if no credit is given to their manure or fertilizing effect upon pastures, cannot exceed $2 in addition. With proper management, and the usage, which should uniformily prevail, of turning off sheep in a vigorous maturity, that estimate will cover the usual contingent loss from disease and accident. An average yield per head of full-blooded merinos should reach 3 cents of wool. The price of the current year is probably a fair medium, and presents for that grade of wool a minimum of about 40 cents. The ter sheep will average three lambs, worth at least three dollars when weaned. The account may, I think, be stated thus: DR. Ten sheep, to one year's keeping By do. 3 lambs, at $1 each - $10 0013.00 3 00 Leaving an excess of $6, the annual profit of ten sheep. I think facts and observations will sustain this calculation. I can more readily illustrate my views by a brief statement of the management and profits of a single flock, with which I am familiar. This flock consists during the winter of about 350 sheep of all classes. The manager selects annually about 100 choice young ewes, not under two years old, for breeding. He usually raises as many lambs as he appropriates ewes to breeding, twins often more than equalizing any occasional losses. He turns off each autumn fat sheep, equal in number to the lambs which he raises. The sheep are at the period of their full vigor and highest value, and command from $1 25 to $1 75. The flock averages 3 centa of wool, which at the present season sold for 44 cents per lb. The casual loss in this flock is so insignificant as scarcely to enter into the estimates of the manager. I am aware that this case exhibits remarkable results, but none that cannot be attained by an exercise of the same judgment and skill. The only peculiar features of this management are those which I have already referred to in the habit of disposing of the refuse of the flock before they become deteriorated by age or disease, and their careful protection from the changes and severity of the climate. The sheep, particularly the feebler portion of the flock, are studiously housed throughout the winter. They are supplied with running water by pipes within the building, which they only leave an hour or two each day for air and exercise. They consume much less fodder by this ar |