158 ILiLINOIS STATE DAIRYMEN'S ASSOCIATION. 



skimmed contained five per cent, of fat and there was two- 

 tenths of one per cent, left in the skim milk. In that way 

 there is a difference, but I do not know of any other reason 

 why there should be a larger overrun from rich milk butter 

 than from thin milk. 



Mr. Judd: Have you had experience with the Marchand 

 test and how does it compare with the Babcock test? 



Prof. Farrington: Some years ago I used it some, but I 

 never made any comparisons. I think that accurate results 

 can be obtained with it, but it requires more expert manipula- 

 tion. 



Mr. Townsend : Do you think the composite test as accu- 

 rate as to take the milk fresh drawn from the cow? 



Prof. Farrington: Yes, it is. The composite test is a 

 mixture of half a dozen samples, or perhaps more, and it gives 

 you a very close average test of all those samples of milk, and 

 it is much less work, and I think that if there is a difference 

 it is not sufficient to pay for the trouble of making the separate 

 tests. We made some experiments to demonstrate that at one 

 time, and we were as near the same result as we could expect; 

 perhaps within one or two-hundredths of a per cent., and T 

 think no one ought to expect duplicate tests of one sample to 

 come nearer than that. 



Mr. Johnson: Does the temperature of the milk at the 

 time of testing make any appreciable difference in the showing 

 of the butter fat? 



Prof. Farrington: As I said before, the intensity of th*e 

 action of the acid on the milk is influenced by the temperature 

 of the milk, just the same as if you wanted to dissolve sugar it 

 will dissolve more quickly in hot water than in cold. 



Mr. Johnson : I have seen men working in a factory take 

 a sample of milk just as it comes from the separator, heat it 

 up to about 80 and make a test and it would show but very 

 little butter fat. 



Prof. Farrington: That was not due to the temperature, 

 was it? 



Mr. Johnson: Partially. My idea is that the milk should 

 always be taken cold, or you will not get a proper measure. 



Prof. Farrington : Of course, you don't want to heat it up 

 to boil, but I think a temperature of 80 or 85, as you get it at 



