NEW YORK MILK COMMITTEE 77 



numbers in the mouths and throats of persons who remain free 

 from symptoms of diphtheria. Of typhoid fever, the germs of 

 which also multiply in milk, we cannot say with certainty 

 that the sufferer does not begin to expel infectious material 

 from his body sometimes during the occasionally long period 

 of general depression which is often the forerunner of what 

 is recognized as the real disease. As to convalescents from in- 

 fectious diseases, it is especially in recent times that we have 

 found reasons which justify the belief that a revision of our 

 ideas, relative to the time when a convalescent can safely be 

 released from quarantine, is urgently needed. 



The more I study this subject the more I am impressed with 

 the belief that the pasteurization of milk must come into gen- 

 eral use. Inspection, bacterial counts, chemical examination, 

 and whatever else we can do for the purification of the milk 

 supply may reduce, but cannot prevent the infection of milk 

 by unsuspected but dangerous human disseminators of disease 

 germs. 



I do not mean, however, when I urge pasteurization, that 

 we should regard its practice as a reason for tolerating evils 

 which only inspection, bacterial counts, etc., can correct. The 

 proper kind of milk to pasteurize is that which is as safe and 

 pure in the raw state as milk can reasonably and economically 

 be made. 



In conclusion I wish to say a few words about pasteurization. 

 The pasteurizaton of milk to be reliable and satisfactory must 

 be conducted under close official supervision. So-called com- 

 mercial pasteurization, without official supervision, is not sat- 

 isfactory, because commercially pasteurized milk has repeat- 

 edly been found to contain virulent tubercle bacilli. The 

 living tubercle bacilli indicate that the milk was not raised to 

 a sufficiently high temperature, or that it was not kept at an 

 elevated temperature long enough, or that it was not heated 

 evenly throughout its entire volume. When mistakes in one 

 direction occur it is fair to assume that they also occur in the 

 opposite direction, and this may explain why some persons 

 have objected to commercially pasteurized milk because of 

 its burned or scorched taste. 



Proper pasteurization means the exposure of milk to a tem- 

 perature high enough to destroy pathogenic bacteria in from 



