MILK FOR INFANTS 149 



of the woman and the nervous influences to which she is 

 subject may tend to make her milk more variable than 

 that of the even-going cow. 



The figures, however, that are given in the above 

 table show less proteids than were found by most of 

 the leading authorities. The average composition of 

 woman's milk, as determined by a large number of 

 analyses, is given by Richmond as follows : 



Water. Proteids. Fat. Lactose. Ash. 

 Woman's milk 88.2 1.5 3.3 8.8 02. 



Johanssen, however, found but 1.1 per cent, of pro- 

 teids, as an average for 25 samples, thus agreeing, in 

 this respect, with the figures given on page 148 which 

 are from Gottlieb. L. P.] 



The first thing to be considered is that the quantity 

 of total proteids in cow's milk is more than three times 

 [or more than twice] the quantity in human milk, so 

 that a child nourished with cow's milk has apparently a 

 considerably greater nitrogen assimilation than a child 

 nourished in the natural way. It is not known with cer- 

 tainty what significance this has for the health of the 

 child, but it is not safe, off hand, to conclude that the 

 highly nitrogenous diet is advantageous. Moreover, the 

 chief part of the protein of cow's milk consists of a 

 casein, which, in contrast with the casein of human milk 

 (the proteids of human milk do not give a curd with ren- 

 net), is precipitated in the stomach as large curds and in 

 a form that apparently makes it less digestible. 



Great importance has been attributed by some to the 

 fact that human milk often contains more fat than cow's 

 milk and, it is affirmed, on this account the nutritive 

 value of human milk is greater than cow's milk. But 

 since we know that the fat content of human milk is sub- 

 ject to great variation (for individual peculiarities see 

 page 24) no particular importance can be attributed, in 



