112 
Quantitative studies of the oxidation of pyrogallol by hydrogen 
peroxide and a peroxidase have also been made by Bach and Chodat ( 31 ) 
with the following results: 
(l) 
[Pvrogallol, 1 gram; hydrogen peroxide, 0.1 gram; peroxidase, from 0.01 to 0.1 gram, 
in 50 c. c.] 
Peroxidase 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 
Purpurogallin 0.021 0.042 0.066 0.083 0.102 0.123 0.145 0.166 
(2) 
[Pvrogallol, 1 gram; peroxidase, 0.1 gram; hydrogen peroxide, from 0.01 to 0.1 gram.] 
Peroxide 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 
Purpurogallin 0.020 0.042 0.060 0.078 0.099 0.121 0.142 0.168 
(3) 
[Peroxidase, 0.1 gram; hydrogen peroxide, 0.1 gram; pvrogallol. 1 to 4 grams.] 
Pyrogallol 1.0 1.5 2.0 3.0 4.0 
Purpurogallin 0.168 0.205 0.203 0.208 0.202 
It would seem therefore that the amount of pyrogallol oxidized 
under these conditions is proportional to both the quantity of the 
peroxidase and of the hydrogen peroxide, but independent of the 
quantity of pyrogallol present, provided that the latter is in excess 
of the quantity capable of being oxidized within the given time by the 
several amounts of the peroxidase and hydrogen peroxide employed. 
NATURE AND MODE OF ACTION OF THE OXIDASES, PEROXIDASES AND 
CATALASES, AND THE CHEMICAL RELATIONSHIPS EXISTING AMONG 
THESE SUBSTANCES. 
The question still remains to be considered as to how these sub- 
stances act as oxygen carriers. We have seen that according to 
Schoenbein they react by ozonizing the oxygen of the air, and in the 
case of the peroxidases, by converting hydrogen peroxide, an anto- 
zonide, into an ozonide, after the manner of lead acetate. On the 
other hand, according to Bach ( 18 ) the oxidases are substances hav- 
ing a special aptitude for forming peroxides. Similar views have 
been advanced by Kastle and Loevenhart ( 244 ). Thus according to 
the peroxide theory of oxidation, when molecular oxygen finds itself 
in contact with the complex autoxidizable substances contained in 
the plant cell, it combines with the same in much the same way that 
it unites with rubidium or benzaldehyde. There is produced under 
these circumstances a complex unstable peroxide which, in turn, can 
give up a part, if not all of its oxygen, to any oxidizable substance 
or acceptor that may happen to be present, or in the event that no 
other oxidizable substance is present, it may oxidize a part of itself. * 
