Alcoholic Enzyme in Yeast. 559 
undergoing decomposition, but that the mercury-manometer 
was not sufficiently delicate to give evidence of it. 
In the bulk of my experiments I relied on the plan of 
taking the weight of a specific-gravity-bottle full of the 
fermenting liquor at the same temperature at approximately 
regular intervals. The same course of action could generally 
be observed, and I will therefore only quote two typical 
observations. 
The first of these extended over a period of about ten days, 
the fermenting liquid being a solution of cane-sugar (40°/ o ) 
mixed with an equal volume of the Yeast-extract. This 
was filtered twice through porcelain before being experi- 
mented with, and the flask was allowed to stand in an 
incubator at 33 0 C. The weighings were taken in a sp.-gr.- 
bottle of 25 cc. capacity. The successive weights are given 
in the following table : — 
Date. 
Time of 
day. 
Hours of 
fermentation. 
Weight 
in gms. 
Loss. 
Loss per hour. 
May 5 
12 noon 
— 
40-7445 
— 
— 
„ 6 
11 a.m. 
23 
40-7385 
.006 
•00026 
» 7 
5 P-m. 
30 
40-732 
•0065 
•00021 
„ 8 
5 P-m. 
24 
40-726 
.006 
• OOO25 
„ 10 
11 a.m. 
42 
40 - 7 2 3 
•003 
.OOOO75 
„ 11 
11 a.m. 
24 
40-722 
•OOI 
•OOOO4I 
>, 12 
5 P-m. 
3 ° 
40-7 1 5 
•007 
.OOO23 
» 15 
5 P-m. 
72 
40-702 
•013 
•00018 
During the first three days the course of action resembled 
that of a weak enzyme, and appeared to confirm Buchner’s 
views. After six days the activity had fallen to one-sixth 
the original amount, which again would not be surprising. 
During the next few days, however, it went up again to the 
original amount, which was quite contrary to one’s experience 
of the action of enzymes. 
In the second experiment I wish to quote, the extract was 
mixed with its own volume of 4o°/ 0 solution of glucose and 
digested in an incubator as before. The 25 cc. weighed 
40-0915 gms., and after thirty hours’ digestion it fell to 
40-0905, showing a loss of -0003 gm. per hour. After this 
time it gained in weight, and the mercury in the proximal 
