THIRTY-FIFTH ANNUAL CONVENTION. 117 



two factors are inseparable, it would be inconsistent to charge 

 the whole difference to mechanical loss. 



In making comparisons like the above, it is perfectly obvious 

 that certain natural difficulties are bound to present themselves 

 which tend to prevent us from obtaining absolute checks. As an 

 example for determining the per cent of fat in butter, it is almost 

 impossible to say just when we have a correct analysis of our 

 butter, due to the fact that butter in the churn is not a homo- 

 genous mass, and portions taken promiscuously here and there 

 may or may not represent an accurate sample of the butter. 

 Then, too, we find that testing of butter fat requires some skill 

 and care, but if the samples are carefully mixed and weighed, 

 very satisfactory results may be obtained. While the presence 

 of these outside factors, causing apparent differences in results, 

 is a source of annoyance to the investigator, they are by no means 

 disastrous to our practical results, but they do serve often to ex- 

 plain apparent error or lack of uniformity in results. 



We also find by comparing the Babcock tests with a number 

 of the chemical determinations for fat in butter that we are able 

 to obtain results which warrant us in using this test in a practi- 

 cal way for determining fat in butter, so it is possible to make 

 the Babcock test our servant to the extent of a complete check 

 from the time the butter fat enters the creamery in the form of 

 milk or cream, until it is sold as marketable butter. 



The accompanying chart seems to illustrate in the best pos- 

 sible way all conditions and gradations where we are making 

 comparisons and seeking for losses when butter fat in the same 

 cream is determined by several testers. The period represented 

 covers fifteen days, or the first half of the month of December. 

 The checks employed are daily testing on individual patrons' 

 cream, made by our regular tester, as compared with similar 

 tests made by the short course buttermakers, a class of eight 

 creamerymen, coming from Northern, Central and Southern 

 Illinois. In addition to using regular checks, composite samples 

 were prepared by each set of testers, so we have not only a 

 comparison of daily checks, but also a comparison of daily and 



