1909] STONE—ELECTRICITY AND MICROORGANISMS 375 
off very little gas, while the treated, under the same temperature con- 
ditions, gave off considerable. The electrical stimulation, under these 
conditions, appeared to act very much as yeast would if subject to an 
increase in temperature. 
In those experiments where the carbon dioxid gas readings were 
made at short and regular intervals, we were able to observe the effects 
of the stimulation on the organisms at different periods. 
In some experiments the observations were made every five minutes 
from the start, and after a number of observations were made and 
recorded, the stimulus was applied. The results obtained in one of 
the experiments, in which five-minute observations were made, are 
given in the curve shown in fig. 2.3 This curve is based on 
the increased amount of carbon dioxid given off by the normal or 
untreated; in other words, the amount of CO, generated by the nor- 
mal in this case would be represented by the base line, or it would be 
equivalent to zero. The treated yeast was given two very small 
sparks from a static machine at 1:50 P. M., or one-half hour after the 
experiment was started. A temperature of 30—35°C was main- 
tained during the experiment. 
The relative amount of CO, given off by the electrically treated 
and untreated yeast before the stimulation was applied showed quite 
a uniform activity on the part of the yeast. Following the latent 
period, which is usually of 15 to 25 minutes’ duration, the results of 
the treatment were manifested in considerable acceleration in gas 
production. This reached its maximum effect at 3:20 P. M., or 1.5 
hours after the stimulation had been applied. Another stimulus 
Consisting of two minute sparks from a Tépler-Holtz machine was 
applied at 3:45 Pp. M. and produced a brief reaction, as shown by the 
curve. The experiment, however, was discontinued at 4:20 P. M. 
In the experiments with yeast there was considerable variation in 
the number and size of the sparks applied to the treated jars, and there 
appears to be an indication, from the results obtained, that in some 
instances the electrical charge was too severe. This was noticed 
in the short-interval readings immediately following the stimulation, 
and in such cases the maximum acceleration period was more remote 
3 We are indebted to Mr. G. H. CHAPMAN, assistant in the laboratory, for super- 
vising this experiment, as well as one other in this se 
