MILK IN ITS RELATION TO INFANT FEEDING 585 



very likely, however, that the difference in the size of the curds 

 given by the two types of milk is due to the difference in the 

 quality and quantity of their salts and probably also the difference 

 in theu' reaction, cow's milk being slightly more acid than human 

 milk. 



In still other ways do human and cow's milk show marked 

 differences. Human milk contains a diastatic ferment which has 

 the power of spUtting starch into maltose and dextrose, and a 

 fat-sphtting ferment, lipase, which is more active than in cow's 

 milk. Human milk also has more antibodies than cow's milk — 

 a factor thought to be responsible for the immunity of breast-fed 

 children to many infectious diseases during their nursing period. 



Whatever the differences between human and cow's milk, one 

 fact is indisputable, and that is that human milk is far better for 

 the human infant than cow's milk. It therefore behooves every 

 mother to nurse her child unless special conditions make it im- 

 possible or inadvisable to do so. Artificial feeding has to be re- 

 sorted to when the mother is suffering from an exhaustive disease, 

 such as advanced tuberculosis, carcinoma, or chronic nephritis, 

 with a constant loss of protein in the urine, the strain of another 

 pregnancy, or the drying up of the breast milk. In cases of this 

 kind the child must be fed on cow's milk. The vital question 

 then arises as to the best modification of cow's milk that will 

 make it approach as nearly as possible the composition of moth- 

 er's milk. 



Milk Modification. — There have been many ways suggested 

 for modifying cow's milk so that it approximates mother's milk. 

 The plan most commonly employed for many years has been the 

 dilution of cow's milk and the addition of sugar and cream to the 

 mixture. In the main, two methods have been followed in the 

 modification of milk. One is based on the percentage principle 

 and the other on the principle of the caloric value of the two kinds 

 of milk. 



The modifioation of cow's milk on a strict percentage basis 

 has been standardized by the late Dr. Rotch, of Boston, who 

 elaborated the methods of Biedert and Meigs. The principle of 

 the percentage system is to modify cow's milk in such a way as 

 to make the protein, fat, and sugar equal the amount present in 

 human milk. To accomplish this it is first of all necessary to 

 dilute the milk so that the protein content is not more than 1.5 

 to 2 per cent. Enough fat in the form of cream is added to make 

 up for the amount of fat lost through dilution. Enough sugar is 

 then added to the mixture to bring the sugar content to 6| or 7 

 per cent, of the total, the exact percentage depending upon the 

 needs of the infant. An illustration will make this clearer: 



