60 
ew» FORMIC ACID 
—_S 
2.0; 
BOTANICAL GAZETTE 
[JULY 
It is evident that the oxygen concerned in this reaction is 
derived from the platinum, and that the more frequently the 
Bh 
A 
Co) 
(e) 
0 
25 ‘50 
SUINGTES 
2.—Curves of the rate of oxidation of 
ecg by hydrogen peroxide: OA repre- 
sents oxidation in absence of a catalyzer; OB repre- 
sents oxidation in presence of colloidal platinum; 
OC represents activity of the catalyzer; ordinates 
represent amount of formic acid produced (stated 
as the difference in number of cc. 0.05M HCl 
required to neutralize the NaOH in 5 cc. of the 
mixture at the beginning of the experiment and 
after a part of it was neutralized by the formic acid 
produced); abscissae represent time in minutes 
platinum is recharged 
with oxygen the higher 
will be the rate of forma- 
tion-of formic acid. It is 
of theoretical interest to 
determine whether the 
rate can thus be made to 
approximate that of the 
production of formic acid 
in the presence of hydro- 
gen peroxide. The latter 
reaction was accordingly 
investigated. 
Since hydrogen perox- 
ide has considerable oxi- 
dizing action on the 
aldehyde in the absence of 
a catalyzer, it was neces- 
sary first of all to deter- 
mine the effect of the 
colloidal platinum on the 
reaction. For this pur- 
pose the following method 
was adopted. Toa solu- 
tion containing the same 
concentration of formic 
aldehyde and sodium hy- 
droxide as used in the 
previous experiment suffi- 
cient hydrogen peroxide 
was added to make the 
concentrationo.5M. The 
rate of oxidation of the 
formic aldehyde in the mixture (which was kept well stirred and at 
a constant temperature of 30° C.) was determined, as in the former 
