140 



MILK HYGIENE 



terial content furnish sufficient evidence regarding its 

 true condition. 



4. The bacteria surviving pasteurization are, for the 

 most part, the quick growing bacteria of putrefaction 

 wliich are inhibited in raw milk by the lactic acid bac- 

 teria, but in pasteurized milk they multiply very fast and 

 undoubtedly they are capable of generating poisonous 

 substances. It has been suggested, therefore, that a 

 pure culture of lactic acid bacteria be added to milk 

 after pasteurization in order to check the bacteria of 

 putrefaction. 



5. In purchasing pasteurized milk, one cannot tell if 



it be fresh or old and cannot determine, from its appear- 

 ance, if putrefaction has begun or if only a few bacteria 

 are present. That this objection to the sale of pasteur- 

 ized milk is valid, is shown by the Copenhagen health 



