1911. | The Alcoholic Ferment of Yeast-juice. 471 
Rate in c.c. of carbon dioxide 
C.c. arsenite added. in‘5 minutes. 
SOPRARwWHL 
Onoa PE 
Eapervment 2'77.—The numbers in the following table refer to 20 c.c. of 
yeast-juice and 1 grm. of the sugar in 35 cc. total volume. 
Rate in ¢.c. per 5 minutes. 
C.c. molar arsenite added. | 
Glucose. | Fructose. 
0 0°34 0°5 
2°5 1oly/ 1°45 
5 PASTE 3°5 
10 Dy rf 7°96 
15 1°48 9°8 
It will be noted that the optimum concentration was not attained for 
fructose, whilst for glucose it was between 5 and 10 c.c. 
(5) When a mixture of ferment, co-ferment, and sugar is rendered so free 
from phosphate that no fermentation will take place without the addition 
of phosphate, this added phosphate cannot be replaced by arsenite. Arsenite 
therefore cannot exercise the same function in alcoholic fermentation as 
phosphate. 
Experiment 28.—The following experiment was carried out in a similar 
manner to Experiment 17 dealing with arsenate. | 
To equal volumes of a mixture of 10 ce. of motes zymin suspension 
+20 ¢.c. co-ferment solution free from phosphate+0:22 grm. of fructose 
were added the following :— 
C.c. CO, in 
18 hours. 
MOF Se CLC WRG TMRPE ED aon octet wie sichenieslels adsciecteia cove cosines 1°5 
23416 3 eet 00:.C.C. ee sedan niniwe dew eanseneneles 38 
See eC) i. +0°5 ,, arsenite Pe i Nn Rapa OR 1:4. 
4, 6c... normal hexosephosphate+0°5 c.c. arsenite ...... 33 
_ The result of (4) shows that the amount of arsenite present was not sufficient 
to inhibit the action of the enzyme, whilst (3) shows that arsenite alone 
produced no increase in fermentation. | 
