100 SECRETION. 



seine was increased from the first day to the second month, 

 inclusive, and diminished from the tenth to the twenty- 

 fourth month ; there was a constant and considerable increase 

 in the proportion of butter, from the first day to the fifth 

 month, and a diminution from the fifth to the sixth, and 

 from the tenth to the eleventh month ; there was a slight, 

 feeble, but almost constant and progressive increase in the 

 proportion of salts from the first day to the fifth month, and 

 a diminution at all other periods. 1 



The differences noted between the milk of primiparse 

 and multiparse were very slight and not very important. As 

 a rule, however, the milk of primiparae approached more 

 nearly the normal standard. 



The menstrual periods, when they occur during lactation, 

 have been found by most observers to modify considerably 

 the composition and properties of the milk ; and it is well 

 known to practical physicians that the secretion is then liable 

 to produce serious disturbances of the digestive system of 

 the child, though frequently these effects are not observed. 

 The changes in the composition of the milk which com- 

 monly occur during menstruation are, great increase in the 

 quantity of caseine, increase in the proportion of butter and 

 the inorganic salts, and a slight diminution in the propor- 

 tion of sugar. The common impression that the milk is 

 unfit for the nourishment of the child if pregnancy occur 

 during lactation is undoubtedly well-founded, though analy- 

 ses of the milk of pregnant women have never been made 

 on an extended scale. Yernois and Becquerel made but 

 one examination of this kind, at the third month of gesta- 

 tion, and found a great increase in the proportion of butter, 

 slight increase in sugar and the inorganic salts, and a slight 

 diminution in the proportion of caseine. 2 



The question is frequently discussed by physiological 

 writers, whether the milk of fair women is different from 

 that of brunettes. There are hardly sufficient data, however, 



1 Op. tit., p. 31. 2 Op. tit., p. 38. 



