CHAPTER III. 



THE BABCOCK TEST. 



34. The Babcock test is based on the fact that strong 

 sulfuric acid will dissolve all non-fatty solid constitu- 

 ents of milk and 

 other dairy products, 

 and thus enable the 

 fat to separate on 

 standing. To effect a 

 speedy and complete 

 separation of the fat, 

 the bottles holding 

 the mixture of milk 

 and acid are placed 

 in a centrifugal ma- 

 chine, a so-called 

 tester, and whirled 

 for four minutes ; hot 

 water is then added 

 so as to bring the 

 liquid fat into the 

 graduated neck of 

 the test bottles, and 

 after a repeated 



Fig. 4. Tlie first Babcock tester made. ^ • ■•• ,, , ,, 



whirling, the length 

 of the column of fat is read off, showing the per cent, 

 of fat contained in the sample tested. 



