THE DAIRY 



101 



tial both for health and for profit on the market. Bad 

 flavors and bad odors in milk are caused by the cows 

 eating improper food and drinking impure water, and 

 by uncleanliness on the part 

 of the dairyman in handling 

 the milk. 



Essentials in caring for 

 milk. In another lesson we 

 shall speak of little plants 

 called bacteria, which live at 

 the roots of the legumes and 

 take nitrogen from the air 

 to help make the plant food. 

 In this lesson we are to 

 learn of another kind of 

 bacteria living in milk and 

 causing it to sour. In the 

 first place, milk sours because 

 bacteria from the air fall into 

 it, begin to grow, and 

 soon change the sugar of the 

 milk to an acid. 



These bacteria are in the air, in water, in barn dust, 

 on bits of hay, and on the cow. They are most plentiful 

 in sour milk, and if we should pour a little sour milk 

 into the fresh milk the latter would sour more quickly. 

 The same thing happens when people put fresh milk 

 into poorly cleaned pails. It follows that all utensils 

 used in the dairy should be thoroughly scalded so as to 

 kill all the germs that cause the milk to sour quickly. 



FIG. 33. A CREAM SEPARATOR 



