RECEIVING, SAMPLING, AND GRADING. 



83 



practised to a considerable extent. This test is in common 

 use in Canada. It consists of heating a small sample of the 

 milk to be tested to 120° F. If it will stand this temperature 

 without coagulating, it is considered to be good milk. If it 



Fig. 25. — Troemner's Babcock creain-te.sting seale.s. 



Fig. 



26. — Tortion cream test- 

 ing scales. 



Fig. 27. — Troemner's Bab- 

 cock cream-testing scales. 



coagulates when heated to this temperature, it is too sour- 

 to be used for cheese. 



This heating may be considered an acid test. When milk 

 contains about .3% acid, it usually coagulates when heated. 

 It should be borne in mind in this connection that different 

 samples of milk do not coagulate when containing exactly the 

 same amount of- acid, and at the same temperature. Some 

 samples will coagulate upon heating when containing little 



