L. G. M. BAAS BECKING AND H. C. HAMPTON 
Amount Peroxide 
in CC. 
Final Pressure 
in cm. 
cc. Oxygen Calculated 
From Titration 
CC. Oxygen Calculated 
From Formula 
I 
1.2 
7-5 
8.2 
2 
2.2 
15- 
16.2 
3 
3-3 
22.5 
23-9 
4 
4.2 
30. 
28.2 
5 
5.6 
37.5 
37.3 
6 
6.8 
45. 
45- 
7 
8. 
52.5 
I 52.5 
8 
9.1 
60. 
' 59-6 
Successive doses of 4 cc. peroxide on the same 4 cc. extract had the 
results shown in figure 6. There are two explanations possible. Either 
(i) the dilution of the solution affects the strength of the enzym, or (2) the 
enzym is ''poisoned" by the peroxide. 
We now made a determination of the influence of dilution by means of 
the titration method. From the results of this experiment we may conclude 
that the action of catalase does not vary with its dilution or with the 
quantity of the peroxide, but only with the absolute quantity of the enzym 
itself. 
The results were : 
Constitution of the Percent Peroxide Decomposed 
Enzym Solution Peroxide after i Minute 
I CC. extract, o H2O 2 cc. 34-6% 
I cc. extract, 3 H20 2 cc. 29.8% 
I cc. extract, 8 H20 2 cc. 33-3% 
I cc. extract, 15 H2O 2 cc. 30.9% 
I cc. extract, 24 H2O 3 cc. 30.3% 
I cc. extract, 35 H2O 2 cc. 31.8% 
I cc. extract, 48 H2O 2 cc. 32.9% 
I cc. extract, 63 H2O 4 cc. 26.9% 
So only the second assumption is valid, the enzym is destroyed by the 
peroxide. 
The reaction times of the successive amounts were : 
T-^ Strength = -r^ 
Time ° time 
1st dose 52 (X I 5/8 sec.) 100 
2d dose 58 89 
3d dose 65 80 
4th dose 75 69 
±10 percent of the enzym is destroyed during every successive reaction. 
This decrease in the reaction velocity supports the unproved assumptions 
of Bredig (I.e.). 
The influence of alkali is very marked. Enzym solutions neutralized 
with Na2C03 hold their power for days. Even neutralized hemp powder 
that had been dried for two weeks showed marked activity. There is a 
strong possibility that the alkali works as a ''peptisator " on the enzym. 
Many peptisators are known in colloid chemistry, alkali acting very strongly 
