272 MEASUREMENT OF THE CATALYTIC POWER OF CATALASE 
reaction : 
1 Vi - (Vh + Ve) + aVe 1 . ^ 
V2 = 1 ~ (H + 2a) 
H 
or the oxygen produced 
V2- {Vi- (Vh + Ve)) =-[2{Vi- (Vh + Ve)} +Ve(H+2a)]. 
ri 
In one case we found : 
Oxygen discharged : 
Vi = 272.19 
Vh = 2 
Ve = 2 
a = 2.3 
H = 76 
Vc = 0.29^ 
^ [2 X 268.19 + 0.29 X 80.6] = 17.2 cc. 
Now the original peroxide was supposed to be 10- volume. We checked 
the experiment by titration at the same temperature and found 8.7-volume. 
This signifies that 2 cc. peroxide would yield 17.4 cc. oxygen. 
Fig. 6. Autogram showing the influence of successive doses of peroxide. 
Thus we see that the autographic method can be used to determine the 
strength of a peroxide solution. 
We can make this clear with an experiment done with 7.5-volume per- 
oxide and 4 cc. extract. The autographic record showed: 
