Bacteria in Market Milk. 2.1.1 



a large amount of dirt will be high in bacteria. The re- 

 verse, however, is not necessarily true. 



2. Acidity test. The acidity of the milk is also an 

 indication of its bacterial content. If the acidity has 



FIG. 40. GOOD MILK. 



A plate culture inoculated with 1/100 of a cubic centimeter of 

 milk containing 67 colonies, which equals 6,700 bacteria per 

 cubic centimeter of milk. Such milk will keep well. 



increased, above the normal for fresh milk, the bacterial 

 content is certain to be high, and the keeping quality 

 poor. An acidity above 0.2 per cent in market milk is 

 to be avoided, as an increase in acidity is always pre- 

 ceded by a great increase of bacteria. 



Whether the acidity is above or below this point can 

 be rapidly and easily determined at the receiving sta- 



