290 DAIRY FARMING 



Pasteurization of Milk. Where no ice is available, 

 the keeping quality of milk may be materially prolonged 

 by a process of heating and cooling known as pasteuriza- 

 tion. This process consists in exposing milk to a tem- 

 perature of about 150 degrees F. for thirty minutes, after 

 which it is immediately cooled to the lowest temperature 

 possible with water. This treatment destroys practically 

 all of the bacteria in milk and thus not only materially in- 

 creases its keeping quality, but also renders it free from 

 harmful or disease-producing bacteria. 



Definition of Technical Terms. A list of technical 



terms not specially defined in the text is presented be- 

 low : 



ALBUMENOIDS. Substances rich in albumen, like the 

 white of an egg, which is nearly pure albumen. 



ANAEROBIC. Living without free oxygen. 



CENTRIFUGAL FORCE. That force by which a body mov- 

 ing in a curve tends to fly off from the axis of motion. 



CHEMICAL COMPOSITION. This refers to the elements or 

 substances of which a body is composed. 



COLLOIDAL. Resembling glue or jelly. 



CONCUSSION. The act of shaking or agitating. 



CUBIC CENTIMETER (c. c.). See metric system p. 203. 



EMULSION. A mixture of oil (fat) and water contain- 

 ing sugar or some mucilaginous substance. 



ENZYMES. Unorganized ferments, or ferments that do 

 not possess life. 



FIBRIN. A substance which at ordinary temperatures 

 forms a fine network through milk which impedes 

 the rising of the fat globules. 



FOREMILK. The first few streams of milk drawn from 

 each teat. 



