ILLINOIS DAIRYMEN'S ASSOCIATION. 55 



Air. Hayden: — Lactic acid would be killed first. 



Prof. Farrington : — I do not think you can safely assume 

 that tbe spore bearing germs will always produce this poison; 

 but when you hold milk that contains any number of germs fully 

 developed, lactic acid germs or spore bearing germs, the lactic acid 

 germs are killed first and the spore bearing germs injure the 

 casein, and when they do the products they produce are putrefied 

 products, so when pasteurized milk spoils it is spoiled by the 

 putrefication germs developing there, acting on the casein, which 

 produces this repulsive odor and smell by their action. I do not 

 think it is safe to conclude that because they do this the spore bear- 

 ing germs produce this odor and that they are always the source 

 of potomaine poisons. 



Mr. Smith : — Would not that be more apt to be harmful 

 upon the children? 



Prof. Farrington : — I do not think anyone knows. 



Mr. Smith : — We do know that lactic acid germs are not 

 harmful. Perhaps you don't know 7 that even if a buttermilk had 

 some sour milk in it it is acceptable on account of the acids it 

 contains, whereas I imagine that a milk in which they had been 

 killed but which had suffered from effects of putrefication would 

 be not only repulsive but unhealthy. 



Member : — Sour milk would not be good food for little 

 children. 



Mr. Smith : — I don't know, we have no children in our 

 family, but I think if you started out in that way you would have 

 to keep it up. We do with calves. 



President : — What temperature kills lactic acia germs, how 

 long at that temperature, and what temperature kills other 

 germs? 



Prof. Farrington : — I never made a special study of this 

 question. Mr. Hayden is one of the students from our bacter- 

 iological department, but I had the impression that a temperature 

 of 130 degrees F. if milk or cream is exposed to that temperature 

 five minutes would kill the lactic acid germs, and a temperature 



