ON THE STABILITY OF THE OXIDASES AND THEIR CONDUCT TOWARD 
VARIOUS REAGENTS. 
By Joseph Hoeing Kastle, Ph. D., 
Chief of Division of Chemistry , Hygienic Laboratory , U. S. Public Health and Marine- 
Hospital Service. 
THE STABILITY OF THE OXIDASES. 
It has been observed that as a class the vegetable oxidases are 
extremely unstable substances. Fresh aqueous extracts of the potato, 
for example, rapidly oxidize guaiacum and phenolphthalin, but on 
standing at room temperature, in the presence of mild antiseptics, 
such extracts soon lose their oxidizing power. The same thing has 
been found to be true of plant oxidases from a great many other dif- 
ferent sources. 
During the past several years a number of fungi indigenous to cen- 
tral Kentucky and the District of Columbia have been examined with 
reference to their oxidizing power. As a general thing these obser- 
vations have afforded nothing of particular interest. 
In the case of the fungus Lejiiota americana , however, the results 
would seem to indicate that, as compared with most vegetable oxidases, 
those present in this mushroom are unusually stable substances. In 
the } T oung state this fungus is nearly white, with a few red spots on 
the pile us. With age, or as the result of injury, it becomes darker 
and of a more pronounced red color. On drying it finally turns to a 
dark brown or black mass, so dark, indeed, as to suggest that it has 
been charred. So far, then, as its general appearance is concerned, and 
the rapid development of pigment in its tissues, everything points to 
the presence of powerful oxidases in its juices. 
With the view of determining its oxidizing powers a 10 per cent 
extract of the fungus was prepared b} 7 macerating the freshly gath- 
ered material with coarse white sand and water, using a small quantit} 7 
of toluene as antiseptic. The filtered extract thus prepared was found 
to be deep wine red in color and to possess remarkable oxidizing 
powers. It gave a splendid guaiacum reaction with fresh tincture of 
guaiacum, and it also oxidized phenolphthalin much more rapidl} T than 
does any other preparation of plant oxidase that has ever come under 
( 7 ) 
