Is produced from the females of all the warm-blooded animals, which are enumerated among the mammaliæ. The milk of several animals is employed for domestic purposes, among different nations. That of the camel is used by the Arabs; the milk of the ass by the Spaniards, the Maltese, and the inhabitants of the Levant; that of the mare by the Cossacks, the Kirgheez, and other Tartars; and that of the goat, the ewe, and the cow, by most of the ancient, and with few exceptions, by every modern European nation. Within the last century, however, the use of all excepting cow's milk has been almost entirely discarded, among the most highly civilized people. If we except some few Welsh and Swiss, or other emigrants, who resort to the goat and ewe for their dairy materials, for the first few years of their residence here, the cow is the only animal which is employed in America for producing milk. For this, she is pre-eminently fitted, and the modern improvement of this invaluable animal has carried her product of milk almost as far as can be reasonably looked for from a given amount of food; and although this is of about the average richness of the goat and ewe, and before that of the ass, the quantity she yields is frequently as 60 to 1, in favor of the cow, over the first two competitors. As a milk-giving animal, the cow is the best fitted for the purposes of civilized man; and she is made to contribute, not only to his health, his comfort, and his economy, but to many of his choicest luxuries. Milk contains every element of nutrition necessary to animal existence; and man can subsist, with unimpaired health and strength, if limited to this food alone. The Constituents of Milk Are butter, which varies from 2 to 6 per cent.; casein or cheese, usually 4 to 5, but sometimes varying from 3 to 15 per cent.; (the last excessive quantity, yielded only by the first milk after calving;) milk-sugar, 4 to 6; salts or saline matter, 0.2 to 0.6; and water, 80 to 89. _There is much diversity in the product and quality of milk_ from cows of the same breed, the same food, and other circumstances and conditions, apparently equal. Thus, of a herd of 22, chiefly Ayrshire, one gave 84 quarts in one week, which afforded 3½ lbs. of butter; two others in the same time gave 86, yielding 5½ lbs.; and a fourth gave 88 quarts, making 7 lbs. The amount of butter, however, which a given quantity of milk will produce, is not the only criterion of the value of the milk, except for this purpose alone. Some cows will yield more butter, others will produce more cheese; while for consumption, another may partially compensate, in the increased quantity of milk-sugar, and the saline matters, for a deficiency of both the other ingredients. But for dairy purposes, butter and cheese are the only measure of the value of milk; and a cow is esteemed good or indifferent, as she gives one or the other in the greatest abundance.