EFFECTS ON ALCOHOLIC FERMENTATION 215 



When portions of a Fleischmann's yeast cake of like weight were 

 exposed to radium rays before being placed in a sugar solution to 

 ferment, the exposure to the preparation of 1,500,000 activity was 

 followed by acceleration of fermentation from the start and through- 

 out, but, following exposure to the salt of 10,000 activity, there was 

 an initial retardation in the rate of fermentation, followed by recovery 

 and acceleration. The quantity of the less active salt in this experi- 

 ment was about five times that of the more active. 



Microscopic examination showed that the budding of the yeast 

 cells was considerably increased by exposure to the rays. 



The fermentation tubes were found to be affected by the rays 

 after being used a number of times so as to cause acceleration of 

 fermentation, even though no radium was present. Reliable re- 

 sults, therefore, may be obtained only by using fresh tubes for each 

 experiment. 



