91 
differs from Bertrand’s preparations of laccase chiefly by the fact 
that the ash is rich in iron, but contains no manganese. According 
to Sarthou ( 358 ) , this iron exists in the active ferment in organic com- 
bination, and to this the ferment owes its oxidizing power. 
OLEASE. 
Tolomei ( 424 ) has observed that fresh olives gradually undergo fer- 
mentation when exposed to the air, with the production of acetic and 
other fatty acids and the evolution of carbon dioxide. According to 
this author these changes are brought about by the action of an 
oxidase to which he has given the name “Olease.” This ferment has 
also been found by Tolomei in the olive oil itself, and to its action are 
due those changes which take place when the oil becomes rancid. 
The acids produced by its action serve to gradually weaken the 
ferment . 
PURPURASE. 
One of the most interesting and picturesque changes attributable 
to oxidizing ferments is that described by Dubois ( 148 ) , which results 
in the production of a purple pigment in the mollusc, Murex brandaris. 
According to this author the pigment glands of these gasteropods are 
analogous to the photogenic (luminous) organs of Pholas dactylus, the 
principal difference being that while the fixation of oxygen in the 
latter gives out its energy in the form of light, the latter absorbs 
luminous vibrations with the production of a pigment. In other 
words, the changes occurring in the production of the pigments of 
molluscs are also photochemical. Dubois observed that on extract- 
ing the pigment gland with absolute alcohol the chromogen contained 
in the gland passed into solution. The alcoholic solution of the 
chromogenic substance was concentrated on the water bath and the 
concentrated solution used to impregnate test papers for the purpose 
of experimentation. The residue of the gland remaining after extrac- 
tion with cold absolute alcohol was extracted first with chloroform 
water, and the residue was finally macerated with glycerin, all of 
these operations being carried out in the dark or in the feeble light of 
the dark room. On adding a drop of the glycerin extract of the 
gland to the test paper containing the chromogenic substance of the 
gland and moistening with water and exposing to sunlight, a purple 
color gradually developed on the paper, the intensity of which de- 
pended on the time of exposure and the intensity of the light. The 
glycerin extract alone is not colored on exposure to the light, and it 
loses its activity when heated to 120° C. in the autoclave. Three 
factors are therefore concerned in the development of the purple pig- 
ment in molluscs, (1) a chromogenic substance soluble in alcohol, (2) 
a ferment, and (3) light. According to Dubois, the chromogenic 
