200 BOTANICAL GAZETTE [SEPTEMBER 
flasks approximately 4.5%™ of a yeast cake were added, to the fourth 
flask nothing. The yeast had been quickly rubbed up in a sterilized 
mortar, with a sterilized pestle, in a small quantity of the sterile 
sugar solution. Thus, on shaking the flask after adding the yeast, I 
hoped to mix the yeast thoroughly with the whole volume of fer- 
mentable liquid. The fourth flask contained, then, only sterilized 
sugar solution, which had been exposed to the air for only a moment 
in transferring it from one sterilized vessel to another. The data 
follow. 
Date Time Flask 1 2 3 4 Room temp. 
no yeast) 
Art Oye: 6:00PM. | r9%rC.} 18°6 18°6 738 
Apt 955250: 9:15 A.M. Cr ee 4 20.5 aI.t 17-5 ‘ 
: 5:30 P.M. 23.3 21.5 22.3 17-7 oy 
PAR 10. oa 8:00 A.M. 24.2 20.6 23.0 17-2 15-3 
12:30 P.M. 24.5 20.8 23-4 ed a? 
Apa 2055 3... 8:15 A.M. 25.0 20.6 24.0 17-3 
12:30P.M. | 25.1 20.7 24.2 17-4 20:2 
At this point, two days and eighteen hours after the experiment 
was started, it was ended and the flasks opened. The odor and 
flavor of the solutions were pleasant. I used the same thermometers 
as in the preceding experiment, but for the reasons previously given 
record here nothing less than tenths of degrees. Of course the ther- 
mometers were sterilized, by standing in saturated corrosive sub- 
limate solution, and afterward washed in sterile water, before being 
introduced into the flasks. The efficiency of a good Dewar flask 
as an insulator is indicated by flask 4 in this experiment; for although 
the temperature of the room varied at least 5° C., as the record shows; 
the temperature within this flask varied only 0°6 C., according to the 
readings taken at the same times. Whether flask 2 was a poor on 
or whether the yeast was poor, or what the trouble was, I do aie 
know. In the other two flasks the mercury rose to a degree which 
surprised me, considering the small amount of yeast sown jn each of 
the three flasks and the small volume of fermentable liquid. This 
rise in temperature indicates the liberation of considerable enetsy 
in the form of heat. 
In connection with these experiments on the respiration of healthy 
