The Eabcock Test. 29 



Sulfuric acid is preferable to other strong mineral 

 acids for the purpose mentioned, on account of its affinity 

 to water; when mixed with milk, the mixture heats 

 greatly, thus keeping the fat liquid without the applica- 

 tion of artificial heat and rendering possible a distinct 

 reading of the column of fat brought into the neck of the 

 test bottles. 



So far as is known, any kind of milk can be tested by 

 the Babcock test. Breed, period of lactation, quality or 

 age of the milk is of no importance in using this method, 

 so long as a fair sample of the milk can be secured. In 

 case of samples of milk or other dairy products rich in 

 solids it requires a little more effort to obtain a thorough 

 mixture with the acid than with dairy products low in 

 solids, like skim milk or whey, which may be readily 

 mixed with the acid. 



A DIRECTIONS FOR MAKING THE TEST. 



35. The various steps in the manipulation of the Bab- 

 cock test are discussed in the following pages; attention 

 is drawn to the difficulties which the beginner and others 

 may encounter in the use of the test, and the necessary 

 precautions to be observed in order to obtain accurate 

 and satisfactory results are explained in detail. The 

 effort has been to treat the subject exhaustively and from 

 a practical point of view, so that persons as yet unfamil- 

 iar with the test may turn to the pages of this book for 

 help in any difficulties which they may meet in their 

 work in this line. 



36. Sampling. The sample to be tested is first mixed 

 by pouring the milk from one vessel to another two or 



