THE BABCOCK TEST 



385 



284. The quality of milk varies mainly in the matter of 

 the fat. Milk fat is found in milk as microscopic globules, 

 one drop of milk containing more than 100,000,000 of them. 

 Eight thousand fat globules placed side by side would reach 

 one inch. The globules are lighter than the other parts 

 of the milk, and therefore rise to the surface or may be 

 removed by the whirling of a separator. About eighty- 

 four per cent of butter is fat. 



285. The Babcock Test. In 1890, Dr. S. M. Babcock, 

 chief chemist of the Wisconsin Experiment Station, in- 



TESTING MILK BABCOCK TESTER. 



vented a method of ascertaining the amount of fat in milk 

 and in milk products. The testing outfit consists of 

 (1) a centrifugal machine, (2) two or more test bottles, 

 (3) a pipette for accurately measuring the milk, (4) an 

 acid measure, and (5) common sulphuric acid. A small 

 testing outfit, suitable for school purposes, or for a small 

 herd of cows, can be bought from any dairy supply house 

 for about five dollars. 



The following is a brief outline showing the successive 

 steps of milk testing : 



