“On the nutrition of cows for dairy purposes,” Dr. Voelcker still further observes that “milk may be regarded as a material for the manufacture of butter or of cheese; and, according to the purpose for which the milk is intended to be employed, whether for the manufacture of butter or the production of cheese, the cow should be differently fed. “Butter contains carbon, hydrogen, and oxygen, and no nitrogen. Cheese, on the contrary, is rich in nitrogen. Food which contains much fatty matter, or substances which in the animal system are readily converted into fat, will tend to increase the proportion of cream in milk. On the other hand, the proportion of caseine or cheesy matter in milk is increased by the use of highly nitrogenized food. Those, therefore, who desire much cream, or who produce milk for the manufacture of butter, select food likely to increase the proportion of butter in the milk. On the contrary, where the principal object is the production of milk rich in curd,--that is, where cheese is the object of the farmer,--clover, peas, and bean-meal, and other plants which abound in legumine,--a nitrogenized organic compound, almost identical in properties and composition with caseine, or the substance which forms the curd of milk,--will be selected.” And so the quality, as well as the quantity, of butter in the milk, depends on the kind of food consumed, and on the general health of the animal. Cows fed on turnips in the stall always produce butter inferior to that of cows living upon the fresh and aromatic grasses of the pastures. Succulent food in which water abounds--the green grass of irrigated meadows, green clover, brewers’ refuse, distillers’ refuse, etc.--increases the quantity, rather than the quality, of the milk; and by feeding these substances the milk-dairyman studies his own interest, and makes thin milk, without diluting it with water, though, in the opinion of some, this may be no more legitimate than watering the milk. But, though the yield of milk may be increased by succulent or watery food, it should be given so as not to interfere with the health of the cow. Food rich in starch, gum, or sugar, which are the respiratory elements, an excess of which goes to the production of fatty matters, increases the butter in milk. Quietness promotes the secretion of fat in animals and increases the butter. Cheese will be increased by food rich in albumen, such as the leguminous plants.