Oo” 
only 21 ce. of oxygen in fifteen minutes, and the entire yolk yielded 
only 1 ce. 
Milk sometimes contains only traces of catalase. In one case 20 cc. 
of fresh cow’s milk gave, upon the addition of 10 cc. hydrogen peroxid, 
only 2.4 ec. oxygen in fifteen minutes. In another instance 20 ce. of 
fresh milk yielded, after the addition of 15 cc. hydrogen peroxid, 9.2 
ec. oxygen in the same length of time.” 
Some observations made by Spitzer* with regard to the amounts of 
oxygen produced by various organs may be added here: 
Dog. Cattle. | Frog. 
ees ae | Blood _Liver Brain | Muscles | Pancreas) Ovaries 
| (1 gram).' (1 gram).|(2 grms.)./(2 grms.)., (1 gram).|(2 grms.). 
ce. G0: cc. G0. - |»! 00) 9a eae 
A NIUGES oe a eee ee | 85 65 30.8 22 | 
Eh hash tee wee, tp an ee eee Ae ee [oeeeeeeees 76 56 54 | 82 48 
| | 
IS CATALASE AN OXIDIZING ENZYM? 
The simple fact that catalase energetically decomposes hydrogen 
peroxid would not in itself justify the inference that catalase is also an 
oxidizing enzym. Such a deduction has, however, some probability, 
since we find this catalytic property together with the power of induc- 
ing oxidations in one other substance, viz, platinum black. But 
platinum black furthermore shows the chief characteristic of the ordi- 
nary oxidase—that of causing, even in the absence of hydrogen per- 
oxid, a blue reaction with guaiac, which reaction is not obtained with 
catalase. With platinum black even reducing actions are known,* the 
writer having years ago shown that nitrates are reduced to ammonia 
by glucose in aqueous solution upon the addition of some very active 
platinum black.’ In this process the oxygen of the nitrates is thrown 
upon the sugar, which is thus converted into acids, while hydrogen 
from the sugar migrates to the nitrogen of the nitrates, yielding 
ammonia. This interesting process, which demonstrates that an agency 
causing oxidations can under other circumstances also cause reductions, 
seems to have remained unknown to some recent writers, to judge from 
their peculiar discussions of the reducing actions in the living cells. 
‘Since catalase and other oxidases are not constant concomitants of milk, it might 
be of interest to compare, in this regard, milk from healthy with that from diseased 
animals. 
* The so-called test of Storch to distinguish boiled from unboiled milk has nothing 
to do with catalase. 
> Pfluger’s Archiv, vol. 67 (1897). 
* Berichte der Deutschen Chemischen Gesel!schaft, Vol. X XIII, p. 675 (1890). 
°The decrease of the nitrate content during the sweating process of tobacco and 
the formation of nitrite (and probably of ammonia) thereby may be due to an 
analogous action of catalase. A short contact, however, does not suffice to accom- 
plish such a change, as a special test showed. 
