IS 
LfiPIOTA AMERICANA IN AIR AND HYDROGEN. 
We have seen that the presence of these powerful oxidases in this 
fungus is closed associated with the development of its splendid red 
color. Such being the case, it occurred to me that it would not be 
without interest to observe its changes in an atmosphere of air and 
hydrogen. According! j 7 a freshly cut piece of the pileus of a young 
specimen of the fungus, the gills of which were practically white, was 
sealed up in a tube in an atmosphere of hydrogen, while another 
similar piece of the same fungus was sealed up in a tube in an atmos- 
phere of air, due precaution being taken, of course, not to injure the 
specimens of fungus by heat. Even after six hours it was evident 
that the specimen in hydrogen was decidedly whiter and less altered 
in appearance than the specimen which had been kept in air. 
These two tubes were kept in a dark closet at ordinary temperature 
for three days. At the end of this time the two specimens presented 
a markedly different appearance. The specimen in hydrogen was 
white, with a small amount of clear yellowish exudate in the tube. 
The specimen in air was dark brown in color, black in spots, and the 
exudate was coffee colored. On opening the tube filled with hydrogen, 
a distinctl} 7 cheesy odor was perceptible and both the fungus and the 
clear yellow exudate rapidly took on the beautiful rose-red color char- 
acteristic of the more highly colored parts of the young fungus itself. 
This in itself shows that the natural color changes occurring in the 
fungus are the result of oxidation. The conduct of the clear yellowish 
exudate toward guaiacum proved to be exceedingly interesting. On 
adding tincture of guaiacum, the characteristic blue color showed itself 
at once. On shaking the solution, however, the blue color showed a 
tendenc}" to disappear; but on allowing the liquid in the tube to come 
to rest the deep indigo-blue coloration of the guaiacum developed on 
the upper surface of the liquid, the depth of the blue zone depending 
on the time of exposure to the air. The middle layer of the liquid 
exhibited various shades of color, varying through dirty shades of blue 
and green, and finally the lower layer of the liquid took on a salmon- 
pink tint, the color of the exudate originally after a brief exposure to 
the air. 
The phenomenon first brought about by shaking the liquid and allow- 
ing it to come to rest could be repeated at will, and always on stand- 
ing the three different^ colored layers made their appearance — the 
top, dark blue, the middle, greenish blue, and the lowest layer, pink. 
In order to show conclusively that the production of the guaiacum 
blue was brought about by the action of the atmospheric air, acting 
through the oxygen carriers present in the original exudate, a small 
amount of the lower layer was pipetted off and transferred to a small- 
bore glass tube in such a way as to inclose a bubble of air. Under 
