ANIMAL. PRODUCT 8 



265 



to high temperatures in shipment to the 

 receiving centers and frequently begins 

 to decompose before being placed in cold 

 storage. It is necessary to check this 

 process by extreme cold. Moreover, cold 

 storage poultry is not drawn, and the 

 bacteria and feces in the intestines pene- 

 trate into the meat more slowly at low 

 than at high temperatures. Experiments 

 have shown that drawn poultry will keep 



result of the rapid multiplication of bac- 

 teria in it. In fact, milk spoils more 

 quickly than any other animal food 

 product. Milk as such does not require 

 preservation for more than one or two 

 days. Bacteria grow 10 to 20 times as 

 fast in milk at a temperature of 75° F. 

 as at 32° F. Milk is considerably altered 

 in its chemical and physical properties 

 by freezing. When milk is partly frozen, 



Fig. 193 — TWO VERTICAL CHEESE SECTIONS. CHEESE CURED AT 40° ON RIGHT 

 AND CHEESE CURED AT 60° ON LEFT 



longer than undrawn birds, but poultry 

 dealers for some reason persist in recom- 

 mending this insanitary method of mar- 

 keting poultry. 



Refrigeration in the dairy — The de- 

 velopment of the dairy industry, the 

 transportation of milk to market, the 

 preservation of market milk, the proper 

 care of milk in the household, the pres- 

 ervation of butter, cheese and other milk 

 products depend on refrigeration. With- 

 out cooling, milk soon becomes sour as a 



the solid portion contains more fat and 

 water and less ash, casein and sugar 

 than the fluid part of the milk. In 

 certain German experiments it seems 

 that if butter be cooled down to a tem- 

 perature of 10° F., it takes on a crystal- 

 line structure, the fat globules are 

 broken up, and the odor and flavor are 

 largely destroyed within a month. At 

 temperatures of 25 to 27° F., butter may 

 be kept in cold storage rooms for six 

 months or longer without harm to its 



