FROM THE PRACTICAL VIEWPOINT 



In 1914, when the writer was connected with 

 the New York City Department of Health, the 

 Board of Health adopted certain modifications in 

 the regulations which had been in force concerning 

 the pasteurization of milk. Among these changes 

 were different rules concerning the temperature to 

 which milk must be heated and the length of time 

 for which it must be held at this temperature if 

 it was to be officially recognized as pasteurized 

 milk. 



Prior to that time, the rules allowed a somewhat 

 wide variation in the heating temperatures, and a 

 corresponding variation in the length of time for 

 which the milk should be held. Thus milk which 

 was heated to 140 must be held at least twenty 

 minutes, while milk heated to 158 need be held 

 but three minutes. Between these extremes other 

 temperatures and holding times were allowed. This 

 sliding scale, as it might be called, allowed such a 

 latitude that milkmen who sold milk in cans only, 

 and were thus not much concerned with the cream 

 line, could heat the milk to a high temperature and 

 hold it for a short time. On the other hand, those 

 dealers who sold bottled milk, and who were desir- 

 ous to obtain as great a volume of cream as pos- 

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