It has already been stated that fresh milk of the cow is the best substitute for the mother's-milk. Some additional observations as to the management of cow's-milk, and as to the substitutes therefor, may, however, be necessary. There can be no doubt that cow's-milk is better than goats' or asses' as a rule, although there are infants who thrive on the two last-named better. In the large cities where it is impossible to procure fresh milk, condensed milk is an efficient substitute. As in the preparation of this the temperature is raised to near the boiling-point of water, it undergoes no change, and can be used when fresh milk is not to be procured, or can not be preserved. Condensed milk is ready for use by mixing it with water in the proportion of one teaspoonful of milk to seven of warm water. When the addition of lime-water is desirable, it can be added in proper proportion. In the author's experience, children, with few exceptions, do well on condensed milk.

Casein is that constituent of milk which is most likely to disagree with infants. Dilution with water, lime-water, barley-water, etc., is not infrequently effective in securing the digestion and absorption of the casein; but some infants are unable to digest it at all. Various expedients are resorted to when the casein fails entirely of digestion. Cream diluted with barley-water sometimes succeeds extremely well. The indigestion of the casein of a given specimen of milk may be due to an insufficient quantity of cream; this defect can be obviated by adding it artificially. When the infant is not nourished sufficiently, and yet does not pass undigested casein, the proportion of cream is probably too low. To assist the digestion of casein, Jacobi recommends that a little well-sweetened oatmeal-gruel be given the infant before taking the bottle, or be mixed with the milk. His method of preparing the food is as follows:

"A teaspoonful of either oatmeal or barley is boiled in from three to six ounces of water, with some salt, for twelve or fifteen minutes, the decoction to be quite thin for very young infants, thicker for later months, and then strained through a linen cloth. Infants of four or six months are to have equal parts of this decoction, which ought to be made fresh for every meal; and boiled and skimmed cow's-milk and sugar are to be added. At an early age, the thin decoction; at a later, the milk ought to prevail in the mixture, which ought to be given at a temperature of 80° to 90°; ought to be neutralized, when acid, with a few grains of bicarbonate or carbonate of potassa or soda, and, until infants are eight or ten months old, thin enough to be taken through a nursing-bottle."

Various substitutes have been proposed for cow's-milk; but they are at best constructed on doubtful principles, and vary greatly in composition. Liebig's preparation has had the greatest celebrity, because of the reputation of its inventor, rather than of its intrinsic merit. It is prepared as follows: An ounce of wheaten flour is mixed with ten ounces of milk; it is then boiled for ten minutes, removed from the fire, and allowed to cool to 90° Fahr. An ounce of malt-powder containing fifteen grains of potassium bicarbonate, and two ounces of water, are then stirred into it, and the vessel, covered, stands for an hour and a half at a temperature of 100° Fahr. It is boiled for a few minutes again, and then strained, when it is ready for use. The object of the malt is to transform the starch into glucose.