128 
Robin and Bordet ( 35 °) have also investigated the action of 
artificial oxidases in infectious diseases and have arrived at the con- 
clusion that the colloidal metals, especially manganese, promote 
oxidation in the tissues and intensify metabolism . 0 They claim also 
to have confirmed the work of A. and L. Lumiere and Chevrotier 
(supra) on the curative action of such substances. Fouard ( 174 ) has 
observed that the halides of the alkalis and the alkaline earths 
exercise a catalytic action in the fixation of oxygen by the polyphe- 
nols, and that the chlorides of the rare earths act even more vigor- 
ously as oxygen carriers ( 175 ). In the title of the latter article, ( 175 ), 
he refers to these reactions as of the oxidase type, and yet there is 
nothing to indicate that the activity of these carriers is destroyed 
by heat, so that, to my mind, the analogy is only the product of a 
very active imagination. 
Martinand ( 288 ) has also pointed out that the oxides of the alkalis 
and alkaline earths which form soluble peroxides and percarbonates, 
give reactions similar to organic peroxidases. He calls attention to 
certain analogies existing between the oxides of the alkalis and the 
alkaline earths and the organic oxidases on the one hand and to those 
existing between certain metallic salts and the peroxidases on the 
other. He is of the opinion that these inorganic oxidases can be 
considered as similar to the organic oxidases in that the former are 
made up of a peroxidase, which is a salt of the metal, and an oxy- 
genase, which is the peroxide formed by the action of the air on the 
salt. Like the organic oxygenases, the inorganic oxygenase can be 
replaced by hydrogen peroxide. These analogies fall short, however, 
in that they fail to take into account the destructive action of heat 
on the oxidases and peroxidases. Wolff f 455 ) has shown that certain 
mineral salts can play the part of peroxidases. Thus, if a trace of 
ferrous sulfate (less than one part per million) be added to an old 
tincture of guaiacum, or to a fresh tincture containing a trace of 
hydrogen peroxide, a very intense blue coloration is obtained. On 
heating’the solution containing ferrous sulfate and hydrogen peroxide, 
it loses its power to blue guaiacum, and traces of mineral acids 
prevent the bluing of guaiacum by the ferrous sulfate and hydrogen 
peroxide just as they prevent the action of the peroxidases, the dosage 
required to inhibit the reaction being the same in both cases. Accord- 
ing to this author these reactions closely resemble those produced with 
plant extracts containing peroxidase, such as extract of malt, etc., 
and he is of the opinion that special interest attaches to these obser- 
vations in view of the fact that salts of iron, like the peroxidases, 
are very widely distributed among living things. He has shown ( 456 ) 
further that certain colloidal compounds of iron are practically 
identical with the peroxydiastases (a name recently proposed by 
a In this connection see also See ( 39S ) and Schade ( 36 °). 
