To secure a more uniform flow and a richer quality of milk, cows are sometimes spayed, or castrated. The milk of spayed cows is pretty uniform in quantity, and this quantity will be, on an average, a little more than before the operation was performed. But few instances have come under my observation, and those few have resulted satisfactorily, the quality of the milk having been greatly improved, the yield becoming regular for some years, and varying only by the difference in the succulence of the food. The proper time for spaying is about five or six weeks after calving, or at the time when the largest quantity of milk is given. There seem to be some advantages in spaying for milk and butter dairies, where the raising of stock is not attended to. The cows are more quiet, never being liable to returns of seasons of heat, which always more or less affect the milk both in quantity and quality. They give milk nearly uniform in these respects, for several years, provided the food is uniformly succulent and nutritious. Their milk is influenced like that of other cows, though to less extent, by the quality and quantity of food; so that in winter, unless the animal is properly attended to, the yield will decrease somewhat, but will rise again as good feed returns. This uniformity for the milk-dairy is of immense advantage. Besides, the cow, when old, and inclined to dry up, takes on fat with greater rapidity, and produces a juicy and tender beef, superior, at the same age, to that of the ox. The operation of spaying is simple, and may be performed by any veterinary surgeon, without much risk of injury. The milk of the cow has often been analyzed. It was found by Haidlen to consist of Water, 873. Butter, 30. Caseine, 48.2 Sugar of milk, 43.9 Phosphate of lime, 2.31 Magnesia, .42 Iron, .47 Chloride of Potassium, 1.44 Sodium and Soda, .66 ------- 1000. But its composition, as already intimated, varies exceedingly with the food of the animal, and is influenced by an infinite variety of circumstances. Skim-milk is much more watery than whole milk. It was found by one analysis to contain about 97 per cent. of water and 3 per cent. of caseine. Swill-milk, or milk from cows fed on “still-slops,” in New York, was found by analysis to contain less than 1.5 per cent. of butter, some specimens having even less than one per cent. The colostrum, or milk of the cow just after calving, contains a large proportion of cheesy matter. Its amount of caseine was found by careful analysis to be 15.1 per cent., of butter 2.6, mucous matter 2, and water 80.3, there being only a trace of sugar of milk.