202 



can turn a crank. Supplied with these advantages the 

 process can be easily demonstrated to be worth its 

 weight in gold. 



Nearly everyone knows that generally the differ- 

 ence between what is called rich milk and skim- 

 milk is in the amount or per cent, of butter fat each 

 contains, hence the butter fat in milk is for all prac- 

 tical purposes a good measure of its value. Usually 

 the butter fat is only one of the constituents of milk, 

 and of the other the casein is of greater importance to 

 the cheese-maker, while the protein substances, as well 

 as the milk sugar and ash, are valuable food. But the 

 greatest importance must be ascribed to the fat, not 

 only because it supplies us with butter, but it is also 

 essential for the best cheese. It may also be accepted 

 as a general rule that milk rich in butter fat has a pro- 

 portionally high content of other solids not fats. 



Observation has repeatedly taught that cream may 

 be " a delusion and a snare " when it is used as evidence 

 for judging the richness of milk. The following inci- 

 dent illustrates this point: 



A person using the milk supplied on a city route 

 complained that the milk was poor, almost no cream 

 Avould rise on it. A chemical analysis of this milk 

 showed it to be slightly above the average composition. 

 This person was accustomed to using milk on the 

 farm where it was subject to no great amount of 

 agitation, and set under favorable conditions. The 

 cream rose much differently on such milk than on the 

 milk bought in the city; although there was not much 

 difference between the two milks in the actual percent, 

 age of water, solids, and fat. We can no more accur- 

 ately judge of the composition of milk by its color 

 and appearance than we can decide on the flavor of an 



