214 effects on alcoholic fermentation 



Experiment 90 

 In order to see if the fermentation tubes had been affected in the 

 preceding experiments by the rays of radium, they were filled with 

 similar amounts of a yeast mixture, made as already described, and 

 placed in the thermostat oven without any radium preparations. 

 Observations were recorded as follows of the volumes of gas given 

 off in fermentation : 



1, 800,000 X 1,500,000 X 10,000 X Ra.-Tel. Control Temp. 



15.60 20.15 22.46 19.12 16.55 



Fermentation in the tubes that have been used a number of times 

 with the radium preparations is more vigorous than the normal 

 (figure 61). The slower acceleration in the tube used with the 

 strongest radium preparation (1,800,000 x ) is possibly due to the fact 

 that this fermentation tube has only been used twice with the radium, 

 while the others have been used 10 or more times. 



Summary 



When sealed glass tubes containing radium bromide of various 

 activities, from 7,000 to 1,800,000, and radio-tellurium were inserted 

 into fermenting mixtures of commercial yeast, the uniform result, as 

 measured by the evolution of gas, was a stimulation of alcoholic fer- 

 mentation. The same kind of result was produced by the celluloid 

 rod coated with a Lieber's radium coating (10,000 x ). 



Observation of the rate of absorption of the evolved gas by the 

 yeast mixture showed different results following exposure to the radium 

 preparations of different activities. This is taken to mean, either 

 that the products of fermentation varied, or that the yeast mixtures 

 were differently affected by the unlike treatment, one or both. No 

 definite explanation is attempted at this time. 



* Estimated. The surface of the mixture had moved off the scale. 



