132 
vation, the changes taking place might be represented graphically 
as follows: 
(1) 
and 
(2) 
or 
(3) 
and 
(4) 
and since, as has been shown by Bach and Chodat ( 27 ) the oxidases 
consist of an oxygenase (an organic peroxide) and a peroxidase, it is 
readily conceivable that oxidations accomplished by the oxidases 
might also be accelerated bv certain oxidizable substances. Thus 
laccol itself might function as a peroxidase accelerator and in its 
oxidation by laccase it might accomplish the oxidation of other less 
readily oxidizable substances contained in the juice of the lac-tree. 
CATALASES. 
One of the most characteristic properties of hydrogen peroxide is 
the ease with which it is decomposed into water and oxygen. Thus 
in the earlier researches on this substance by Thenar d ( 420 ’ 421 ) it was 
observed that this decomposition can be effected by finely divided 
metals, by the oxides and peroxides of the heavy metals, and also 
by substances of animal origin such as fibrin. We have already seen 
that these observations were greatly extended by Schoenbein ( 383 ). 
He proved that certain plant juices blued guaiacum directly; after 
standing for a short time, however, they lose this property but still 
retain the power to blue guaiacum in the presence of hydrogen perox- 
ide, although this property is also lost after a time. Such extracts 
and juices were also found to have the power of decomposing hydro- 
gen peroxide with the evolution of oxygen gas, and as a general thing 
he observed that extracts and tissues having the power to decom- 
pose hydrogen peroxide have also the power to blue guaiacum if 
hydrogen peroxide is present. Yeast and rennin, however, proved 
to be exceptional in their conduct in this regard. Both of these 
substances were found by Schoenbein to decompose hydrogen per- 
oxide, yet neither had the power to blue guaiacum in the presence 
of hydrogen peroxide. According to Schoenbein the power to decom- 
pose hydrogen peroxide and to blue guaiacum containing small 
amounts of the peroxide were not specific properties of any particu- 
lar class of substances but rather general properties of all soluble fer- 
ments, since the soluble ferments exhibit these changes and since the 
loss of its specific activity on the part of any particular soluble fer- 
ment by the action of heat or otherwise is attended with the loss of 
P + H 2 0 2 — >P0 2 ; 
P0 2 +H=P+A0 2 ; 
2P0 2 +A =2PO +H0 2 , 
H0 3 +P=H0+P0, 
