342 



FARM ANIMALS 



FIG. 181. Milk-testing Machine. 



Note. 17.6 c.c. of the milk to be 

 tested is put into a test bottle. An equal 

 amount of sulphuric acid is added. This 

 dissolves all the solids of the milk except- 

 ing fat. The mixture is shaken thoroughly 

 until it becomes of an even dark brown 

 color. The bottle is then put into the 

 machine and is made to revolve rapidly 

 for five minutes. The machine is then 

 stopped and the bottle filled to the neck 

 with hot water, then whirled again for 

 three minutes, then filled again with hot 

 water to about the 3 mark on the neck. 



c.c. 



\ 



a 

 rt 



Testing Milk. All creameries now pay for their 

 milk on the basis of the percent- 

 age of butter fat present as re- 

 vealed by the Babcock test. This 

 is a device invented by Dr. Bab- 

 cock of the Wisconsin Experi- 

 ment Station. 



c.c. 



FIG. 182. 



1 



PQ 



It is now whirled again 



