Asses’ milk is probably the best substitute for an infant’s natural food; and failing this, goats’ milk is to be preferred to that from the cow. Whichever is employed, it is best to buy the animals and have them kept in one’s own compound, so that one can ensure, by personal supervision, their being cleanly kept and carefully fed. Before milking, the animal’s teats and the hands of the milker should be washed in boracic solution, which should be kept ready made up in a large earthen vessel (an Indian gurrah, for example). A great drawback of cows’ milk as a food for infants in India lies in the fact that, whereas human milk has a distinct alkalinity, that of the breeds of kine indigenous to that country is often (in my own experience, always) rather strongly acid, even when freshly milked from perfectly sound and well-cared for animals. Generally speaking, indeed, the acidity is so considerable that the amount of alkali contained in even twice its bulk of lime water, is quite insufficient to neutralise it. In place, therefore, of the conventional lime water, it is better to add about as much as will stand on a sixpence, of a mixture of equal parts bicarbonate of soda and citrate of potash, to each bottle. Of course, if you wish to be exact, you can get from your chemists some books of litmus paper which change to a redder tint when dipped into an acid fluid and become bluer when moistened with an alkali; and it is a good plan to test in this way, at any rate to commence with, in order to ascertain roughly the amount required for the milk of the particular cow that yields the milk. The citrate of potash, besides being for practical dietetic purposes an alkali, has the additional valuable property of preventing the milk, after it has reached the infant’s stomach, from curdling in large masses, as cows’ milk is apt to do unless treated in this way. Human milk, when curdled in the process of digestion, does so in small flocculi; and the tendency of cows’ milk to curdle in large masses makes it a frequent cause of dyspepsia as well as of diarrhœa. Whether or no the peculiarity of possessing a so strongly acid reaction is shared with the milk yielded by cows in other hot climates I cannot say. Whatever may be the source of the artificial food, it is needless to remark that it should be sterilised by means of one of the numerous appliances now sold everywhere for the purpose, and that care should be exercised to guard against chill to the abdomen. The prevention of infantile diarrhœa is in fact purely a question of guarding against impure and unsuitable food, and though the same is no doubt also true for more temperate climates, precautions which may be sufficient in an English summer, break down at once in a moist heat of 90° in the shade.