38 A DAIRY LABORATORY GUIDE 



EXPLANATION. USE OF HAND MACHINE 

 IN BABCOCK TEST 



It is a popular notion that milk cannot be tested 

 accurately in a hand machine. This is a mistaken 

 idea, as a hand machine should do as good work as 

 any other machine. One of the chief reasons for 

 inaccuracy in using a hand machine is the inatten- 

 tion paid to the temperature. It is necessary to 

 have the proper degree of heat in order to perform 

 properly the Babcock test. To provide the proper 

 temperature the hand machine should be filled with 

 hot water up to the bottle cups if the room is at all 

 cold. The small two-bottle and four-bottle hand 

 testers have no frame, and so the bottle cups are 

 made large in order that they may be filled with 

 hot water if necessary. While it is not absolutely 

 necessary to use hot water at all times, its use is 

 always advisable. By its use the danger of test- 

 ing milk at too cold a temperature is largely done 

 away with. The operator should be careful to keep 

 the machine to its proper speed during the entire 

 run. 



