182 



H. S. H. WARDLAW. 



Although the significance of the mean values of the 

 results of a series of analyses such as the above is in general 

 not so apparent as might be desired, the mean values of the 

 results of the above series have been given, together with 

 the maximum and minimum values, both for comparison 

 with the results of other investigators, and because, as 

 will be shown later, mean values may approach values 

 having a definite significance when the number of observa- 

 tions is fairly large, as in the present case. 



Table III. — Maximum, mean, and minimum values of the density 

 and composition of the samples of human milk examined. 



Maximum 



Mean 



Minimum 



Density. 



1-0370 

 1-0321 

 1-0260 



Total 

 Solids. 



15-5 

 131 



9-4 



Fat. 



7-65 

 3-14 

 0-56 



Solids 

 not fat. 



12-2 



10-0 



6-2 



Protein 



4-2 



2-00 



0-95 



Solids not 

 fat nor 

 protein. 



11-9 



8-0 

 3-8 



The results for sample 29, which was colostrum, are not 

 included in the above table. The figures in the table show 

 how widely separated are the limits between which the 

 composition of the samples of human milk examined in the 

 present case varied. The mean values, it will be noticed, 

 are not very different from those of the investigators quoted 

 at the beginning of the paper, with the exception of the 

 values for the percentage of protein given by Oamerer and 

 Soldner {loc. eit.), which differ from the values given by 

 the majority of other workers. It must be remembered, 

 however, that the present results are for the milk of the 

 first week of lactation only. 



4. The most probable composition of human milk. 



When a series of measurements of a certain quantity is 



made, the results of these measurements are found, in 



general, not to be identical, but to differ among themselves, 



even when the quantity measured is assumed to remain 



