194 



H. S. H. WARDLAW. 



great majority of the samples dealt with in the present 

 paper were obtained four to five days after the commence- 

 ment of suckling. 



6. Effect of age of woman on composition of milk. 

 In the samples of human milk which Leeds (loc. cit.) 

 examined, he found that the average composition of the 

 milk of women under twenty years of age showed higher 

 values in the amount of every constituent than the milk of 

 women over twenty years of age. In the following table 

 the average compositions and densities of the human milks 

 examined in the present investigation are arranged accord- 

 ing to the ages of the women from whom they were obtained. 

 The samples obtained from primiparse have been kept 

 separate from those from multipara. 



Table VI. — Effect of age on composition of human milk. 





Primiparee. 



Multipara. 



Age. 



20 and 

 under. 



21 to 30 



31 and 



over 



20 and 

 under 



21 to 30 



31 and 



over 



No. of results 



15 



. 28 



1 



8 



37 



12 



Density 



1-0319 



1-0323 





1-0326 



1-0319 



1-0314 



Total solids ... 



12-4 



12-2 



13-3 



12-1 



12-9 



12-4 



Pat 



3-15 



2-67 



3-46 



2-87 



2-98 



2-97 



Solids not fat 



9-4 



9-5 



9-8 



9-2 



9-9 



9-4 



Protein 



1-91 



2-06 



1-68 



1-88 



2-40 



1-96 



Solids not fat 



7-7 



7-1 



8-1 



7-3 



7-5 



7-4 



nor protein 















No very clear evidence of a definite relation between 

 the age of a woman and the composition of the milk secreted 

 by her seems to be shown by the above figures. There is 

 some evidence, however, that the percentage of protein is 

 higher in the milk of women between the ages of 20 and 30 

 than in the milk of women younger or older than this in 

 the case of primiparae as well as in that of multiparse. 



