308 Messrs. A. Harden and W. J. Young. [ Mar. 6, 
Hzpervment 20.— 
(1) 25 cc yeast-juice+ 5 c.c. phosphate+15 c.c. bicarbonate. 
(2) e2dne%c: “ +10 cc. Bs +10 ce. r. 
(3) 29: ¢.¢, . +15 ce. F + 5 cc. " 
(4) 25 ee, re +20 cc. re + 0c. 7 
The concentration of glucose was 4°5 grammes per 45 c.c., and the experi- 
ment was carried out at 25° in presence of toluene. 
Carbon dioxide evolved in preceding 5 minutes with » cubic centimetres 
Time after of 0°3 molar phosphate added. 
addition 
in minutes. 
nm =.5 C.C. nm = 10 c.c. Ny —=wlanescs nm = 20 cc. 
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ep 
me 7 0 bo 7 
oo 30H 
a 
ern p we oom Ddy 
TWOOMOAKOHENW-T 
ONTIATSCOHODNDIHAMSTNbwWwnwe 
SDODHAAUIMHMWMOHROHAOKRG 
ANMIAHaHBWnAnKRRWOWWNYDNYDNNDOHE 
SEMODODNIDOLANHWAWDOOANSA 
Meealey all eae ected eet 
Pea ale biped 
et | 
Curves A, B, C, and D (fig. 1) show the rate of evolution per five minutes 
for the four solutions in experiment 20. The time of addition is taken as 
zero, the rate before addition being constant, as shown in the curves. 
It will be observed that in experiment 19 practically the same maximum 
is attained with 10 and 15 cc. of phosphate, whereas, in experiment 20, 
5 and 10 cc. give the same maximum, whilst 15 ¢.c. produce a much lower 
maximum, and 20 cc. a still lower one, the rate at which the velocity 
diminishes after the attainment of the maximum being correspondingly 
slow in these last two cases. By calculating the amount of phosphate which 
has disappeared as such from the amount of carbon dioxide evolved, it is 
found that the maximum does not occur at the same concentration of free 
phosphate in each case. 
These results suggest that the phosphate is capable of forming two or 
