The Babcock Test. 29 



Sulfuric acid is preferable to other 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 application 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, qual- 

 ity or age of the milk are of no importance in using this 

 method, so long as a fair sample of milk can be secured. 

 In cases 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 prod- 

 ucts 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 

 Babcock test are discussed in the following pages; at- 

 tention is drawn to the difficulties which the beginner 

 and others may encaunter 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 ex- 

 haustively and from a practical point of view, so that 

 persons as yet unfamiliar with the test may turn to 

 the pages of this book for help in difficulties which 

 tlicy 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 



