34 



MODERN METHODS OF TESTING MILK 



fc 



FIG. 7 



MILK-TESTING 

 BOTTLE 



FIG. 7a 



NECK SHOWING 

 TEST-BOTTLE GRADUATION OF 

 8% MILK 8% MILK-TEST 



BOTTLE 



serum, the completion of the separation of fat is ef- 

 fected by centrifugal force. When the bottles con- 

 taining the mixture of milk and acid are whirled, the 

 centrifugal force acts more strongly upon the 

 heavier portion, that is, the mixture of acid and milk- 



