METHODS OF REDUCING THE GERM CONTENT 



539 



one of the milk bottles. Experience has shown that home treat- 

 ment of water or milk is not always successful. For the greater 

 part of the population, milk pasteurized on a large scale is prob- 

 ably the safer milk. 



Directions for home pasteurization of milk are given by Rogers 

 as follows: A small pail with a perforated false bottom is used. 

 An inverted pie tin with a few holes punched in it answers the 

 purpose. The bottles of milk are placed on this false bottom and 



Fig. 219.— Desirable arrangement for Fig. 220. — An especially con- 



pasteurizing mili for infants' use. structed pail devised in dairy labo- 



ratory for efficient pasteurizing and 

 cooling of milk. Can be made by 

 any tiimer. 

 (Frandsen in Bull. No. 39, Univ. of Neb. Agri. Exp. Sta.) 



a good thermometer inserted into one of the bottles. The pail is 

 filled with water nearly to the surface of the milk, and heated until 

 the thermometer shows a temperature of not less than 145° F. 

 nor more than 150° F. (Figs. 219, 220). The bottles are then re- 

 moved and covered with a towel to hold the temperature for 

 twenty to thirty minutes. The milk is cooled by placing the 

 bottles first in warm water — to avoid breakage — and then in cold 

 water. Lastly they are placed on ice. A wire basket can be used 

 to hold the bottles, as shown in Fig. 221. In this case the bottles 



