206 



In the same way, if milk be " sold on test " by cream- 

 ery patrons, or on any regular route, is the composition 

 of milk uniform enough to depend on one test of it 

 every seven, ten or thirty days, oris the cow machinery 

 set to such an uneven gauge and the tendency of man 

 to err so great, that a test must be made of every lot 

 of milk in order to deal fairly and do justly with all % 



At the present time almost every one, and especially 

 the farmer, works on such a narrow margin of profit, 

 that the necessary expense of time makes it impracti- 

 cable to test every lot of milk each day. 



A satisfactory substitute for this large amount of 

 test work is obtained by collecting and testing " com- 

 posite " samples of milk. 



If a small quantity of a cow's milk is put into the 

 same glass fruit-jar after each milking, the jar will 

 contain at the end of a week a mixed milk representing 

 14 milkings, provided the cow was milked twice each 

 day. 



This mixture of milk is called a "composite" sample- 

 A test of such a sample has been proposed in place of 

 testing each of the 14 samples. 



When more than one cow is to be tested in this way, 

 each one must have a separate " contribution box," 

 plainly marked, so that the daily sample will be put in 

 the right place. 



This system has been adopted by creameries where 

 the patrons are paid for the test or butter fat in milk 

 instead of the pounds of milk. A common pint or 

 quart glass fruit- jar is a very convenient receptacle 

 for holding the composite sample of milk. 



A jar is provided for each patron and marked w T ith 

 his name. Every time he brings milk to the creamery, 

 it is weighed and a small quantity, about 1-10 of a 



