I must stop for a moment to consider the proper and natural food for infants. This is, of course, mother's milk; but if not obtainable either from the child's own parent or a foster mother, then cow's or goat's milk, treated so as to resemble human milk, should be substituted. Milk is a typical food, inasmuch as it contains all the elements necessary for nutrition, namely, albumen or nitrogenous matter, fat, a carbo-hydrate in the form of sugar of milk, salts, and water. The albumen is chiefly in the form of casein, which can be precipitated or thrown down from the milk by an acid or rennet. It is thus that cheese is made from milk. The fat is suspended in the milk as minute globules, which can be clearly seen under the microscope. These globules of fat, being light, rise in the form of cream when milk is left standing for some time. Thus skimmed milk is milk deprived of its fat, though as its albumen remains it is still a highly nutritious food for adults, but is inadmissible for infants. The sugar in milk is called lactose. Unlike ordinary sugar it cannot cause alcoholic fermentation. The mineral salts, though small in amount, are of great value from a dietetic point of view.

To know how to feed an infant properly when human milk is not available, it is necessary to know the nutritive value of other kinds of food, and to ascertain if they contain, in the proper proportions, the four necessary elements, namely, albumen, fats, carbo-hydrates, and mineral salts.

The following table gives the comparative analysis of the various kinds of milk: -

From this we see that cow's milk is richer in nitrogenous elements and fat than human milk, so that to make it suitable for infants it must be properly diluted; goat's milk is also richer, but ass's milk is much poorer than human milk. Now compare these perfect foods with the materials frequently given to hand-fed infants, and which are productive of rickets. To do so the following table should be studied: -

It will be apparent on comparing this table with the previous one giving the various milk analyses, that the farinaceous foods which are given to children and frequently to hand-fed infants, are deficient in fat and contain a superabundance of starch. This deficiency may be made good by the addition of milk, or still better, of cream to the bread, flour, or biscuit used. Obvious as may appear the teachings of nature, it is a fact that some mothers, finding cow's milk disagree with their infants, and not knowing how it should be diluted and treated to make it digestible, will proceed to feed them on biscuits soaked in water, arrowroot, bread and skimmed milk, or on patent foods mixed with water, with the inevitable result of producing rickets. The fat and the albumen necessary for nutrition are withheld, and the child is fed, or rather starved, on starch. Now starch, it will be observed, has no place in milk, and it forms, moreover, no element in the proper dietary of an infant, inasmuch as infants in the early stage of existence have no power of digesting or assimilating starch. Dr. Cheadle, in his admirable book on the Artificial Feeding of Infants, gives an instructive case of the production of rickets by deficient food, in children of ignorant, though well-to-do parents. The parents were prosperous tradespeople, but the mother was too much occupied with business to suckle or attend to her children. Of five born healthy three had died in infancy. The child Dr. Cheadle was called to see was eleven months old, and had all the signs of well-marked rickets. The symptom which had, however, alarmed the parents was spasm of the glottis, so severe as to threaten suffocation. On inquiry it was found that all the children had been hand-fed on a patent farinaceous food, cornflour, and arrowroot made without milk, cow's milk having disagreed with them. Thus these little ones were starved to death, though abundantly fed. A proper dietary effected a cure in the case of the infant yet alive.