whereas to the latter the laccase ow T es its zymotic characteristics, 
such as destructibility by heat, poisons, etc. 
According to Portier ( 330 ), the following properties are characteristic 
of an oxidase : 
(1) The power to oxidize certain substances in the presence of free oxygen, gaseous 
or dissolved . 
(2) The power to cause the absorption of oxygen during oxidation. 
(3) Destruction by heat. 
(4) Nondialyzability. 
According to Bourquelot ( 84 ), the oxidases belong to the class of 
enzymes and possess the following characteristics common to enzymes 
in general: 
(1) Catalytic power, viz., power to effect the transformation of an indefinite amount 
of material by means of an infinitesimal quantity of the ferment. 
(2) Like other ferments, their activity is subject to regular and constant influence 
by heat, increasing in oxidizing power with rise in temperature to 42°-45° C. (optimum 
temperature), then falling off in activity with further rise to 60°-70° C., and finally 
completely destroyed at 100° C. 
(3) Insolubility in alcohol. 
(4) Solubility in water, even after precipitation by alcohol and desiccation. 
(5) Adsorption by precipitates (colloids). 
(6) Absence of power to dialyze. 
In addition to these general characteristics, they possess, according 
to this author, the following properties properly belonging to the 
oxidizing ferments : 
(1) Power of accomplishing oxidation by means of gaseous or dissolved oxygen. 
(2) The accompaniment of the oxidations accomplished by them with a notable 
absorption of oxygen. 
Duclaux ( 150 , vol. 2, p. 565), has defined oxidases as substances 
which at ordinary temperatures and under physiologic conditions, 
carry oxygen rapidly to substances upon which, without the inter- 
vention of oxidases, ordinary ox}^gen would act very slowly. 
The oxidases are very readily soluble in water; they are also readily 
soluble in glycerin, but in other organic solvents thus far investigated 
they seem to be insoluble. Thus I ( 238 ) have found the oxidase of 
Lepiota americana to be very soluble in water, glycerin, 40 per cent 
formaldehyde, and mixtures containing water and alcohol, but insolu- 
ble in ethyl, amyl, and allyl alcohols. This fungus also gave up its 
oxidase to a preservative solution containing equal quantities of 
water and alcohol to which a small amount of formaldehyde had been 
added. Some observations seemed to show that it was soluble in 
toluene to some extent. It has also been my own experience that 
aqueous solutions of the oxidases are very unstable even in the pres- 
ence of mild antiseptics. Thus aqueous extracts of the potato soon 
lose their power to blue guaiacum, even when preserved under anti- 
septic conditions. Bourquelot observed that an aqueous extract of 
Russula delica when preserved with chloroform first loses its power to 
