TESTING DAIRY PRODUCTS BY THE BABCOCK TEST. 79 



about 70 F., if not already at that temperature, then fill the bot- 

 tle up nearly to the base of the neck (point A, fig. 8) with sul- 

 furic acid, specific gravity 1.82. The acid can be handled in a 

 sharp-nosed pitcher or run in from a syphon affixed to a carboy. 

 Mix the acid and cream together thoroughly, which is best done 

 by grasping the neck with the hand, pressing the thumb tightly 

 over the opening and then giving the bottle a rotary motion, 

 holding it upright all the time. The confined air prevents the 

 curd from coming up and sticking to the sides of the neck. The 

 mixing is just as easily done in this as in the old style bottle. 

 The remainder of the process is conducted exactly the same as 

 in testing milk, described on pages 70-72. 



If the above directions are followed, a perfectly clear separa- 

 tion will be obtained, with a considerable saving of time over the 

 old method, as only one pouring of the acid and one whirling of 

 the machine are made. The precautions given on page 72 

 under "Testing Milk" apply also to cream. 



APPLICATION OF THE TEST. 



The test is applicable to all problems involving a knowledge 

 of the content of butter fat in dairy products. In the pages 

 which follow, the most important uses of the method are pointed 

 out. • 



THE TEST APPLIED TO THE FARM. 



The Babcock test may well be said to be invaluable to the 

 farmer, as it gives him a simple and accurate method of testing 

 his cows with much less labor than was required by the old 

 method, with the churn. By its use he can weed out his poor 

 and unprofitable animals, which are eating up the profits of the 

 good cows. Every farmer keeping five or more cows should 

 have access to a tester. 



How to Test a Cozv. Milk the cow thoroughly dry at the 

 usual hour. A pail sufficiently large to hold the entire amount 

 of milk given should be used. After the milking is completed, 

 mix the milk thoroughly by turning it two or three times from 

 one pail to another, then immediately take out the sample to be 

 tested. Testing a single milking, however, shows only whether 

 the cow is giving very rich or very poor milk, and does not fur- 

 nish an accurate knowledge of the quality of her product, for 



