COMPOSITION OF HUMAN MILK IN AUSTRALIA. 



193 



normally does not last longer than forty-eight hours, does 

 not seem to have been examined in detail. Practically all 

 of the human milk, the analyses of which are given iu this 

 paper, were obtained during this immediately post-colostral 

 period, and the results of these analyses have been arranged 

 in the following table so as to indicate how the average 

 composition alters during these first few days of lactation. 

 The samples from which the table has been compiled were 

 obtained from women who had been suckling for periods 

 ranging from two to eleven days. 



Table V. — Variation of composition of human milk with stage of 



lactation. 



Sucklia g 

 for 



Number 



of 

 samples 



Density. 



Total 

 solids. 



Fat. 



Solids 

 not fat. 



Protein. 



Solids 

 not fat 



nor 

 protein. 



1 - 2 days 



3 



1-0337 



14-8 



2-84 



12-0 



3-30 



8-7 



3-4 „ 



39 



1-0322 



12-2 



2-84 



9-4 



2-33 



7-0 



5-6 „ 



36 



1-0320 



12-2 



2-64 



9-6 



2-06 



7-5 



7-8 „ 



13 



1-0319 



12-3 



3-27 



9-0 



2-02 



7-0 



9-11 „ 



11 



1-0308 



13-5 



4-13 



9-4 



1-69 



7-7 



It will be seen from this table that the average values 

 of the density and protein fell during the period of obser- 

 vation ; the fat remained almost constant for a time and 

 then rose considerably; the amount of total solids fell 

 rapidly at first, this fall being due to the large decrease in 

 the amount of protein associated with the disappearance 

 of colostrum, then rose again as the amount of fat present 

 increased; the amount of solids not fat fell rapidly at first, 

 and then fluctuated slightly, but did not move steadily in 

 any direction; the amount of solids not fat and not protein 

 varied in the same way as the amount of solids not fat. 

 On the whole the composition did not alter materially after 

 the second day. The author hopes to deal with the later 

 stages of lactation in detail in a subsequent paper. The 



M— August 4, 1915. 



