L. G. M. BAAS BECKING AND H. C. HAMPTON 
267 
This reaction (4) would be true when A — B = o seconds. 
This is the reaction given by most authors. G. Bredig {I.e.), however, 
doubted the value of this equation. He found the reaction velocity con- 
stant. Therefore, he argues, the reaction must be monomolecular, and 
follow the scheme : 
H2O2 -> H2O + o 
But the oxygen liberated is not atomic oxygen; it is not ionized, but 
molecular. T. H. Kastle and A. S. Loevenhart^^ defend on this ground the 
validity of the bimolecular equation. We are not able to follow their 
criticism of Bredig's work, and we will only remark that in the case in which 
A — B>o the whole controversy seems to be solved. In fact, the first two 
reactions in the scheme of Bach are monomolecular. 
IV. 
We will compare now the action of two different quantities of enzym. 
The line A-B'-C (fig. 2) gives the action of the smaller quantity. What 
method must we follow to find out the ratio of their strengths? 
1. Reaction veloeity. The more accurate investigations deal with reac- 
tion velocity. We will show that the enzym is destroyed during the reaction 
(see below). Therefore the reaction velocity diminishes (sometimes very 
slightly) as nearly all authors have shown. (Issajew, I.e., however, finds 
a constancy to the third decimal.) The reaetion veloeity is therefore a mislead- 
ing test for the strength of an enzym. 
2. Amount of peroxide decomposed. This method, though much used, 
has very little value, as figure 2 will demonstrate. A determination of the 
ratio in strength between A-B-C and A-B'-C would give: 
At B', 10:5; 
E, 10:7; 
F, 10:9; 
G, 10:10. 
Still we find in the literature on the subject, expressions like this: 
"There is three times as much catalase in the body wall of Ascaris suum as 
in the leg muscles of Rana pipiens'' (Magath, I.e.). 
3. A better method is the direct measurement of the reaction time 
(see above, II). This is possible only with a self-recording apparatus. 
We prepared our materials by the method thus described. The tops 
of female hemp plants were ground in a meat-grinder with a small amount 
of powdered Na2C03. The ground substance was then squeezed in a fruit 
press. The turbid fluid obtained is very stable and still strongly active 
after the lapse of fourteen days. The determinations all took place at 
20° C. The peroxide was the usual commercial 10- volume H2O2, which 
23Amer. Chem. Journ. 29. 1903. 
