10 
without interest, inasmuch as by means of the oxidase reagents here 
employed we can readily distinguish between this mushroom and man}" 
other species. While it would be premature to say that all mushrooms 
failing to give the oxidase rehctions are poisonous, it can be said that 
any white-gilled fungus failing to show these reactions must be regarded 
with suspicion. 
The glycerin extracts of these fungi prepared during the month of 
July were kept in the cold room — temperature = 15° C. — and practi- 
cally in the dark until December 28, 1905, when they were again tested 
with guaiacum and aloin, with the following results: 
No. 
Name of fungus. 
Color with guaiacum. 
Color with aloin. 
1 
2 
Lactarius piperatus 
Russula emetica 
Very dark blue 
Light blue, slow 
Light red, slow. 
None. 
3 
Lactarius volumen 
Dark blue 
Deep-wine red. 
Faint pink. 
Wine red, slow. 
Do. 
4 
5 
Volvaria bombycina 
Lactarius , indigo 
None 
Dark blue 
6 
Clitocybe ochro-purpurea 
Light blue, darker on stand- 
7 
Yellow fungus, variety un- 
ing. 
do 
Do. 
8 
9 
10 
determined. 
Small white fungus, variety 
undetermined. 
Agaricus campestris 
Amanita verna 
Dark blue 
Light blue, slow 
None 
None. 
Do. 
It is clear from these results that at low temperatures, in the dark, 
glycerin extracts of certain fungi, notably Lactarius pipjeratus , Lccc- 
tarius volumen , and the indigo lactarius retain their oxidizing powers 
practically undiminished for four months. On the other hand, cer- 
tain of these, which in the fresh state possess remarkable oxidizing 
powers, such as Volvaria bombycina and the undetermined yellow 
species, No. T, rapidly lose their power to effect the oxidation of gua- 
iacum and aloin, even when carefully preserved in glycerin, at 15° C. 
As might be expected, the stability of the oxidases seems to be greatly 
influenced by the nature of the other substances with which they may 
happen to be in contact. Thus it has been found that they are less 
stable in water than in glycerin. Further, the stability of their 
aqueous solutions seems to be largely determined by the nature of the 
antiseptic with which such solutions are preserved. That such is the 
case may be gathered from the following observations: 
Aqueous solutions of Lactarius piperatus and fungus No. 7 were 
prepared on August 4, 1905, and preserved in glass-stoppered bottles 
with small amounts of toluene, chloroform, and thymol, respectively, 
as antiseptics, in the dark at 15° C. These solutions were tested 
with guaiacum and aloin on December 28 with the following results: 
