1911.] The Alcoholic Ferment of Yeast-juice. 473 
The effect of adding glycogen to the juice is to 
micmense the total Dy > s.c.....s.sececeeseeeSveesescuas To ( 078 = 59 
The effect of adding the arsenite alone to the juice 
mate.imerease the total by 2 ./...........0..0eseeeeees 118:°3—67°8 = 50°5 
Sum of separate effects of glycogen and arsenite... 505+ 5°9 = 56-4 
Effect of adding glycogen and arsenite together is 152°1—67:'8 = 843 
Hence at least 843—56-4 = 27-9 cc. more carbon dioxide have been 
derived from the glycogen in the presence of arsenite than in its absence in 
the same time. 
(7) Arsenite produces its effect by accelerating the action of the hexose- 
phosphatase. 
Experiment 32.—The experiments on this point were carried out exactly 
as described under arsenate (Experiments 19, 20,21), but, in addition, the 
auto-fermentation of the juice (d) was observed— 
Total c.c. evolved in time f. 
a | b | C. d. | a—b | c—d 
5 4:1 2°6 1:0 0°6 1°5 0°4 
10 TG. 4°8 2°2 i fo | 2°9 1:1 
15 11°2 7°0 3 °4 1°9 4 °2 1°5 
20 14 °8 9 °4 4,°6 2 °4 5 °4 2°2 
25 17°9 1:7 5°6 2°8 6 °2 2°8 
55 35 °7 24 °2 10 °7 6 °2 11°5 4°5 
60 38-7 26 °7 12°3 6°8 12-0. 5°5 
65 41 °7 28 °8 13 *2 7°3 12°9 5°9 
As already explained, the original fermentation due to hexosephosphate 
alone is given by c—d, and the enhanced fermentation due to hexose- 
phosphate by a—0. The effect of arsenite on the hexosephosphatase is very 
much less than that. of arsenate, as was to be expected from the relative 
effects of the two on the fermentation of sugar, and is only clearly visible 
when the original auto-fermentation is subtracted from the fermentation in 
presence of hexosephosphate. The result in this case therefore depends on 
the assumption that the presence of the hexosephosphate and the products 
of its hydrolysis does not seriously affect the rate of hydrolysis of the 
glycogen. 
Euperiment 33.—An experiment was also carried out with washed zymin 
in precisely the same way as described for arsenate (Experiment 23) 
hexosephosphate being made the sole source of phosphate. 
10 c.c. of washed zymin suspension+15 c.c. of co-ferment solution free 
d 
