PUEE versus, purified milk 251 



Before making any attempt to judge the value of 

 this criticism, let us first of all make sure that we 

 mean the same thing by the use of the word " pas- 

 teurization." There is no legal definition of pasteur- 

 ization. There is no city or state anywhere, so far 

 as I know, which has established a legal standard 

 of what constitutes pasteurization. The result is 

 that every dealer is entitled to adopt a standard of 

 his own. There is less difference between raw milk 

 and some kinds of pasteurized milk than there is 

 between different kinds of pasteurized milk. A 

 great deal of the milk which is commercially pro- 

 duced and sold as pasteurized milk is simply heated 

 to a temperature of about 150° Fahrenheit for twenty 

 or thirty seconds and then rapidly cooled. It is 

 admitted that this does not very greatly reduce the 

 number of tubercle bacilli, though it may kill prac- 

 tically all the germs of scarlet fever, 95 per cent of 

 typhoid and diphtheria germs, and as much as 90 

 per cent of all the bacteria." Of the tubercle bacilli 

 a very large proportion are not killed.* 



So far, then, much of the criticism is justified when 

 directed to a great deal of milk ordinarily sold as 

 pasteurized milk. It does not follow, however, that 

 it also holds true of scientific pasteurization, such 

 as that practised in many foreign cities and at the 

 Straus laboratories in -this country. This scientific 

 method is to keep the milk at a temperature of 167° 



