ioo MILK [vi 



Mare's Milk. 



Water 91-53 



Milk-Sugar . . . . 1-25 



Lactic Acid . . . . 1*02 



Casein . . . . 1-91 



Fat 1-27 



Alcohol . . . . 1-85 



Carbonic Acid . . . '88 



Mineral Matter -29 



100-00 



Koumiss may be made by adding a little cane- 

 sugar and yeast to skim milk. 



Both these beverages have a high dietetic value, 

 and koumiss has of recent years been used by 

 medical men as a tonic. The dietetic value does 

 not seem to be due to the alcohol they contain, but 

 chiefly to the peptonised condition of the casein, 

 which is thus more easily digested. 



Pathogenic Germs. The bacteria which we have 

 just been discussing may be regarded as, for the most 

 part at any rate, normal inhabitants of milk. There 

 are, however, a class of microbes which may be 

 regarded as abnormal. These are the so-called 

 pathogenic or disease-producing bacteria, which we 

 have already mentioned, but not yet discussed. It 

 may be well to discuss very briefly this question. 



The method in which these pathogenic germs act 

 differs in the case of different germs. Some directly 

 absorb their nutriment from the surrounding sub- 



