140 PROFITABLE DAIRYING 



a. To determine the fat content of skim-milk. Trans- 

 fer 17.6 c.c. pipetteful of skim-milk to a double neck 

 bottle. Add about 20 c.c. of sulphuric acid. Mix well 

 and test as in the case of milk, except that only one 

 filling with water is necessary. The points to be observed 

 in testing skim-milk are: 



1. Use excess amount (or over 17.5 c.c.) of sul- 

 phuric acid. 



2. Whirl a minute or two longer than in the case 

 of whole milk test. 



3. Do not allow mixture to cool. 



b. To determine the fat content of buttermilk. Use 

 double neck bottle, as in the case of testing skim-milk; 

 also u~e excess amount of sulphuric acid. 



c. To determine the fat content of whey. Because 

 there is very little casein in whey, it is evident that it is 

 not necessary to use so much acid as in the case of skim- 

 milk or buttermilk; 12 to 14 c.c. are usually sufficient. 



Note: It is very essential that the neck of the double neck 

 bottle be perfectly clean and dry in order that the air may 

 have free access. 



