156 ILIilNOIS STATE DAIRYM'ElN'iS ASSOCIATION. 



in testing milk should not be taken as an infallible rule, and 

 understood to mean that the color of the fat is always an indi- 

 cation of the strength of the acid used, but rather an attempt 

 to demonstrate and explain some of the various difficulties met 

 with in testing milk, and to be of some aid in overcoming 

 them. 



There is generally a reason for allthe peculiar effects met 

 with in milk-testing and satisfactory explanations for them 

 can usually be obtained by using one's mind as well as a 

 mighty manner. 



DISCUSSION. 



The Chairman: I think this milk testing is a part of our 

 creamery work that is not understood, and especially by the 

 patrons. I am convinced from frequent experiences that pa- 

 trons do not understand the necessity of the thorough mixing 

 of the milk before they take the sample for testing. We can- 

 not see the process of cream raising, and it is very hard indeed 

 to realize it. I hope the patrons will not hesitate to ask Prof. 

 Farrington questions. 



Mr. Dean: Will the Professor please tell us how he gets 

 the butter test after he gets the oil test — what rule he goes by? 



Prof. Farrington: Of course you all understand that the 

 butter contains a variable quantity of substances that are not 

 fat. It contains some water, some salt and some casein, and 

 most any two lots differ in the amount of water which they 

 contain. The fat which separates in the Babcock test is 

 always the same thing ; there is no water in it ; it is a definite 

 substance. Now, that is the basis for paying you for the 

 amount of butter that you brought to the creamery, and in or- 

 der to get the increase of the churn over the test, as it is often 

 called, why the factory keeps a record of the amount of butter 

 that they made during the month from a certain amount of 

 milk. Then, of course, from the test of each patron's milk and 

 the weight of the milk, they can figure up how much butter fat 

 there was in that butter, and the difference between the two 

 represents the overrun, and the creamery managers generally 

 claim that percentage; that is, the difference between the 



