374 BOTANICAL GAZETTE [NOVEMBER 
centage of CO, given off in these was greater for a given period than 
in some of the others. All of the other experiments were run at room 
temperatures, which in some instances were fairly good, and in others 
the room was too cool to expect much activity on the part of the yeast. 
The small amount of CO, given off in some instances is therefore due 
to the temperature conditions under which the experiment was made, 
and moreover, since these experiments in some instances lasted four 
days, there was more or less absorption of CO, by water in the 
graduated cylinders. 
TABLE XIII 
Showing the influence of electricity on yeast 
NUMBER OF cc OF CO2 GIVEN OFF IN 
NATURE OF ELEC- DURATION OF 
EXPERIMENT TRICAL STIMULUS EXPERIMENT 
Normal Electrical 
Wiese cis oak galvanic 2 hours 174 212 
| ree ay Ponce ae galvanic 3 days 752 838 
Cis wees galvanic 2 hours 189 232 
C By ree galvanic 3 days 540 700 
Oita galvanic 4 days 20 296 
Vacs See galvanic 4 days ° 1200 
Pee ee es static* 1.5 hours 112 129 
| oe gre See static 2 hours 74 102 
ae Brewer static 7 hours 82 I 
| aes See i 3 days 922 1035 
Pee eee ae static 2 days 300 575 
by eyed Sante static 4 days 15 140 
* ¢ gi 8 sparks; j and /, 5 each; k, x spark; h, 2; and #, 3. 
The absorption of CO, by water was noticeable when the yeast 
cultures were left over night, especially when the room temperature 
was low and the yeast not active. The absorption of water, however, 
was apparently the same in both the treated and untreated series and 
did not affect the relative results. In some cases, therefore, a larger 
amount of CO, was given off than is shown by the records in the 
tables. 
Frequent observations and readings were made of the amount of 
CO, given off, but to make the tables brief we have given only the 
final readings. 
The effects of electrical stimulation seem to be more pronounced 
in the lower temperature experiments than in those where there was 
a high temperature. In some instances the untreated cultures gave 
