256 ECONOMY OP THE HOUSEHOLD. 



cheesy matter from three to ten per cent., and the serous 

 matter or whey from eighty to ninety per cent., the pro 

 portions of these several substances varying according 

 to the kind of animal, the food used and other circum 

 stances. 



931. Though to the naked eye it appears to be of the 

 same character throughout, under the microscope a 

 myriad of little round or oval globules, of unequal sizes, 

 are seen floating in the watery matter. These globules 

 arc particles of butter enclosed in a thin film of cheesy 

 matter. They are so minute that they filter through the 

 finest paper. 



932. Milk weighs about four per cent, more than water. 

 Cold condenses while heat liquefies it. The elements of 

 which it is composed, being different in character and 

 specific gravity, undergo rapid changes when at rest. 

 The oily or butter particles being lighter than the rest, 

 soon begin to rise, to the surface in the form of a yellowish 

 semi-liquid cream, while the greater specific gravity of 

 the whey carries it down. 



933. The butter particles in rising to the surface, bring 

 up with them many cheesy particles, which mechanically 

 adhere to their external surfaces, thus giving the cream 

 more or less of a white instead of a yellow color, as well 

 as many watery particles which make it thinner than it 

 would otherwise be. 



934. If the globules rose up free from the adhesion of 

 other substances, they would appear in the form of pure 

 liu tter, and the process of churning would bo unnecessary. 

 The collection, or coagulation of the cheesy particles, by 

 which the curd Incomes separated from the whey, some- 

 limes lakes jilacc so rapidly, (Vom llic effect of great heat 

 and sudden changes in the atmosphere, that there is not 



