58 
Resell ( 352 ) distinguishes between extra-and intra-cellular ferments, 
and divides the oxidases into the following groups: 
(1) Aldehydases (Jacoby), such as salicylase, etc. 
(2) Indophenol-oxidase (Spitzer), found in aseptic pus (Achalme). 
(3) Guaiacum oxidase (Schoenbein), found in plant tissues. 
(4) Hydrogen peroxide ferment (Rosell), peroxidase (Linossier), indirect oxidase 
(Bourquelot), and possibly includes catalase under this head. 
(5) The glycolytic ferment (Lepine). 
(6) The purin oxidase (Spitzer). 
The following classification of the oxidases and other oxygen-car- 
riers concerned in biological oxidations would seem to be more in line 
with present requirements: 
(1) Laccase; ferments oxidizing guaiacum, guaiacol, hydroquinone, phenolphthalin, 
tannin, etc., directly by means of atmospheric or dissolved oxygen and without the 
intervention of hydrogen peroxide. According to Bach and Chodat, laccase consists 
of a peroxidase, together with an oxygenase (a peroxide). In this connection, see also 
a recent communication by Moore and Whitley ( 306 ). 
(2) Tyrosinase; ferments acting on tyrosin and related substances. 
(3) Aldehydase; ferments oxidizing aromatic aldehydes and related compounds. 
(4) Indophenol oxidase (Spitzer), ferments oxidizing a mixture of a-naphthol and 
para-phenylene diamine to indophenol and other substances. 
(5) The purin oxidases. 
(6) Glycolytic ferments, causing the disappearance of sugar from animal tissues. 
In addition to the oxidases proper, we have among related ferments 
and carriers the following: 
(1) Peroxidases; oxidizing oxidase reagents only in the presence of a peroxide, 
such as hydrogen peroxide. These are the indirect oxidases (Bourquelot) and the 
^-oxidase of Griiss. According to Moore and Whitley ( 306 ) the peroxidase is the only 
type of enzyme concerned in oxidizing processes occurring in living cells and tissues. 
(2) Catalases (Loew). These ferments actively decompose hydrogen peroxide, but 
are incapable of effecting the oxidation of oxidase reagents by means of the peroxide. 
(3) Oxygen carriers (not true ferments). This class includes such substances as the 
iron-containing pigments of the blood, hemoevanin, and the /--oxidases of Griiss. 
They activate the oxygen of a peroxide, but differ from the true peroxidases in having 
greater stability. (See Kastle ( 240 ).) 
Whether the laccase, tyrosinase, aldehydase, etc., obtained from 
different vegetable and animal sources are really in all cases the same 
substances can not be determined with certainty in the present state of 
our knowledge respecting these substances. As already indicated, a 
very large number of plant tissues contain an oxidase capable of 
bluing guaiacum and oxidizing hydroquinone; whether this is the 
same chemical substance which is responsible for these oxidations in 
all cases can not be definitely decided. For certain reasons it would 
seem probable that the substances responsible for such oxidations, in 
case there were several, are at least closely related chemically. On 
the other hand, certain facts are known which would seem to indicate 
that they might have the greatest diversity of composition and yet 
