298 BOARD OF AGRICULTURE. [Pub. Doc. 



antee a certain specific quality. If lie can secure supplies 

 of extra quality, and can find customers who are willing to 

 pay extra price if the quality is assured, he can warrant that 

 the customer will receive what he pays for. With the Bab- 

 cock tester the farmer can know what he is selling. If he 

 ships to the Boston contractors, he can, by the use of the 

 Babcock tester, remove nmch of the mystery which has 

 hitherto enveloped the statute standard. He can keep su- 

 pervision over the quality of his milk sales and can know 

 whether he is sending standard milk or not. If he receives 

 complaint from the contractors, he has proof from his own 

 tests of the kind of milk that has left his farm. 



In order to understand the use of the Babcock tester in 

 the sale milk business, a few fundamental principles about 

 milk must be understood. First, the milk of individual 

 cows varies from day to day. If the milk of a cow were 

 to be analyzed every day, and the results of those analyses 

 represented pictorially ])y a line which should go up as the 

 quality of the milk increased, and vice versa, the line would, 

 speaking in a general way, be something like a row of V's : 



vvvvvvv- 



This is a somewhat exaggerated statement, because the 

 irregularities will not be as uniform as is indicated by the 

 above, and because, as the period of lactation increases, the 

 amount of solids in the milk will increase ; ])ut in a general 

 way the above is a representation of the quality of milk 

 from day to day of individual cows under normal conditions. 

 Ordinarily this variation is less than one per cent, and when 

 the quality goes up one day it usually comes down about as 

 much the next day. Second, when the milk of several 

 cows is considered we find that these {variations in the dif- 

 ferent animals are not all alike at the same time, ])ut where 

 the milk of one cow shows an increase, this increase may 

 be offset by a decrease in the quality of milk of another 

 cow. Hence the mixed milk of a herd is more constant in 

 quality than the milk of single animals, and does not vary 

 much from day to day. Where the conditions of barn and 

 feed are such that the cows can have an adequate amount of 

 food under comparatively uniform conditions, when they 

 are neither too cold in winter, nor obliged to tramp long 



