THE MICROBE OF MILK 87 



the milk to some extent to sour, they work not a 

 little mischief. Some cause the milk to curdle, 

 make it ropy, or even taint it. Others give the 

 milk different hues of color, of blue, red or yellow. 

 They have no business to meddle with the milk 

 enemies to the milkman, pure and simple. 



The milkman has two means of successfully 

 avoiding these pests. First, cleanliness. Keep 

 the cows clean. Keep clean the stable. Keep 

 clean the milk cans and other utensils. Second, 

 as soon as the milk is taken from the cow, reduce 

 it to a low temperature, and keep it there until 

 used. 



The microbe that simply causes the milk to sour, 

 without any attendant mischief, is the real friend. 

 True, the early souring of the milk may be trouble- 

 some to the milkman. But he has an easy remedy. 

 He should Pasteurize the milk; that is, before dis- 

 tribution, heat the milk to 165 degrees. This de- 

 stroys all the germs in the milk which sour it. 

 The milk will then keep sweet practically long 

 enough. 



The milk, before used by the customer, should be 

 Pasteurized anyway. After it comes from the cow, 

 several hours usually intervene before it reaches 

 the customer. By this time every glass of it, as 

 we have said, contains millions upon millions of 

 germs. To the adult, or persons in vigorous 

 health, these germs are harmless. But to invalids 

 and young children it is not safe. If, therefore, 

 the milkman Pasteurizes his milk just before distri- 



