If the additional expense of certified milk can be met, it is advisable to use it in preparing the baby’s food, as it is reasonably constant in its composition and is prepared under the most hygienic conditions, in accordance with the requirements of the American Association of Medical Milk Commissions. All utensils used in preparing the baby’s milk must be absolutely clean. Bacteria develop very quickly in milk and, therefore, the bottles, nipples, etc., should be kept as germ-free as possible by being boiled daily, and the nipples, when not in use, should be kept in a solution of boracic acid (one-fourth ounce boracic acid to one-half pint of water). The artificially fed baby does not usually thrive as well as the breast-fed infant. It does not gain in weight as fast and the teeth are slower in coming. The general condition of the baby, and a steady, even if slow gain in weight, will indicate whether the food is agreeing. Every baby, however, is a law unto itself and it sometimes requires considerable study to determine what is the best food. Even with the utmost care a cow’s-milk preparation cannot be made identical with mother’s milk and sometimes an entirely different mixture must be resorted to. However, no mother should attempt to experiment on her baby or permit herself to be misled by the advertisements of so-called Baby Foods. It is only when these are used in the right proportion and in combination with other ingredients that they can be suited to the requirements of the infant. * * * * * [Sidenote: Milk Modifications] Malt used in place of milk-sugar or cane-sugar will greatly assist the absorption of fat and decrease the tendency to fermentation and colic. It is being extensively used in milk modifications. It is best to use the dextrin-maltose preparations that do not contain sodium chlorid, as it is rarely advisable to add this salt to the infant’s food. Some physicians have been securing very satisfactory results with a preparation containing whey. Whey is a thin, watery fluid, looking very much like skimmed milk; its caloric value is about 300 per quart, 9 per ounce, barely one-half that of whole milk. It is therefore adapted only to temporary feeding, while its low fat content is of great value in cases of fat dyspepsia.