FOODS FOR USE IN THE DAIKY. 141 



conditions as the general churning, and this test deter- 

 mines not only the quality of the milk and the butter, 

 but the time occupied in the churning, which is quite 

 important. The butter made is accurately weighed, and 

 compared with the quality* of the milk, and that of the 

 cream known from the test in the per cent glass. The 

 buttermilk is also tested by the ether test, which is by 

 using a long test-tube marked with equal spaces — tenths 

 of an inch — and putting into it a certain quantity of but- 

 termilk, then a small quantity of ether, and shaking the 

 tube for a few minutes, after which it is set to rest, and 

 any butter in it appears on the top dissolved in the ether. 

 The tube is set in a warm place and the ether evapo- 

 rates quite quickly, leaving a film of butter on the butter- 

 milk. This test is not of much practical importance, be- 

 cause a small quantity of butter will remain in the but- 

 termilk in spite of the best churning; but it serves to 

 show that some milk leaves more butter in the butter- 

 milk than others. But when all the different miilks are 

 mixed, the butter which escapes from one milk may be 

 caught and gathered by the other milk, and while the 

 butter globules of one cow's milk are so small that some 

 will be lost when her cream is churned alone, they are 

 picked up by tlie Lirger globules of other milks. This 

 fact is proved by the n^e of a microscope, which shows 

 clearly how the milk of various cows differs in this re- 

 spect. The quality of the butter is learned by taste and 

 by the melting point, which indicates its hardness and 

 firmness. This is an important test, because at times the 

 cream of some cows varies in character, and especially 

 as the cow approaches a new calving the flavor becomes 

 quite distinct and will affect the butter of other cows. 



The feeding test is the most interesting and soon 

 gives the dairyman a very clear idea of the value of his 

 cows. The food is changed in quantity — decreased or 

 increased — and the result is noted by the previously de- 



