IO8 MODERN METHODS OF TESTING MILK 



the separatory funnels should be thoroughly cleaned. 

 This is easily done with hot water together with soap 

 or cleaning-powder, after which the funnels are well 

 rinsed with clean water and allowed to drain. 



PREPARATION OF SAMPLE OF CHEESE 



Since different portions of the same cheese vary in 

 composition, special means must be used to get a 

 representative sample. The sample for testing is pre- 

 pared as follows: When a cheese can be cut, a nar- 

 row, wedge-shaped segment is taken, reaching from 

 the outer edge to the center. This is cut into strips 

 and passed through a meat-grinding machine two or 

 three times. This mass is carefully mixed, and from 

 this a sample is weighed. 



When cheese can not be cut, samples are obtained 

 by a cheese-trier. If possible, three plugs should be 

 drawn, one at the center, one about an inch from the 

 outer edge, and one at a point half way between the 

 two. If only one plug can be drawn, this should 

 be taken at a point about half way between the mar- 

 gin and center. The plugs should be taken perpen- 

 dicular to the end surface of the cheese and should 

 reach either entirely through the cheese or just half 

 way. The plugs should be made fine by grinding or 

 cutting and carefully mixed before weighing samples. 

 In preparing samples, they should not be exposed to 

 the air longer than necessary, since loss of moisture 

 should be prevented as much as possible before weigh- 

 ing. 



