1916] REED—OXIDASE REACTIONS 307 
The peroxidase activity of the two preparations was then com- 
pared by removing them from the electrolytic apparatus, washing 
them quickly by dipping them several times into a considerable 
volume of distilled water, 
and placing them sepa- 9 
rately in flasks, each of 8 
which contained 100 cc. 
of the following mixture: 
0.1M_ fermaldehyde, 
0.03M NaOH, and ap- 
proximately o.1M H,0,. 
The solutions were kept 
well stirred and at a con- 
stant temperature of 18° 
C. on a water bath. At 
frequent intervals por- 
tions consisting of 2 cc. 
each were removed and 
titrated with o.o5M HCl 
for the amount of formic 
acid produced from the 
oxidation of the formal- 
dehyde. The results are 
indicated in fig. 1, where 
the curve representing the 
action of the oxidized 
platinum is seen to be 
identical with that which 
represents the action of 
the reduced platinum. 
The points indicated by 
an©represent the reac- 
tion of oxidized platinum, 
and the points indicated 
by a X represent the reac- 
“tor fe hei 
& 
A. 
8 10 
SUNUTES 
Fic. 1.—Curve showing oxidation of for- 
maldehyde by hydrogen peroxide in presence s 
colloidal platinum: points indicated by © a 
from an experiment in which the platinum had 
been subjected to active oxygen just previous 
to placing it in the formaldehyde mixture; 
points indicated by Xare from * end © expe ri- 
tin in whi ch the Ti Ly 
subjected to active hydrogen; ordinates repre- 
sent amounts of formic acid formed (expressed 
as the difference in number of cc. of o.o5M HCl 
required at the beginning and during the course 
of the experiment); abscissae represent time in 
minutes. 
platinum h 
tion of reduced platinum. It is thus apparent that the two prepara- 
tions of platinum are equally effective in this oxidation. Oxidation 
