194 THE MILK QUESTION 



tempted. It is true that if milk is heated to or near the 

 boiling temperature it afterwards putrifies, but temper- 

 atures between 60 and 65 C. do not kill all the lactic acid 

 bacteria. Ayers and Johnson showed that milk as it is 

 pasteurized in America sours normally. These results have 

 been confirmed by the Chicago Board of Health and also 

 by Dr. Schorer in my laboratory. Therefore the bug- 

 aboo that nature's danger signal is destroyed in pasteur- 

 ized milk vanishes before the facts. 



Pasteurized milk, therefore, does not keep much longer 

 than the raw milk, and the question of the limitation of 

 the age of pasteurized milk, therefore, partly answers itself. 



Laws and regulations concerning pasteurization 



The cities of New York and Chicago were tbe first 

 to recognize pasteurization as a public health measure 

 upon the statutes and to proclaim laws regulating its prac- 

 tice. 



There is no regulation of the health department of the 

 city of Boston covering the pasteurization of milk and milk 

 products. In the year 1908 a state law was adopted by 

 Massachusetts, which, however, is inoperative because of 

 the high temperature specified therein (167 F.). 



In Chicago, Commissioner Evans promulgated compre- 

 hensive regulations anent the pasteurization of milk and 

 milk products. These regulations go into the subject in 

 commendable detail. 



In New York City the sanitary code of the department 

 of health adopted regulations April 22, 1908, containing 

 rules for pasteurization, amended January 4, 1912. 



Bother cities and states appear backward in promulgat- 

 iws and regulations upon the subject of pasteuriza- 



The temperature and time of heating 

 The dominant factor that controls the temperature and 

 time at which milk should be pasteurized is the thermal 



