20 
and certainly for most, if not all, of the actual cases thus far investi- 
gated, such an assumption is, as we shall see, more in harmony with 
the facts, since the formation of such peroxides as A0 2 rests on indis- 
putable experimental evidence. 
From his studies on the electrification of gases, Schuster ( 392 ) as- 
sumes that under the influence of the electric current the molecules 
of gaseous substances are broken up at the negative pole. A number 
of chemists in attempting to account for the activation of oxygen 
have thought it necessary to assume the decomposition or disruption 
of the oxj^gen molecule through the action of oxygen carriers. Thus 
in 1870, Loew ( 276 ) advanced the view that in slow and rapid oxidation 
the splitting of the oxygen molecule into its atoms occurs. Fuda- 
kowsky ( 177 ) concurs in this view. 
From his study of fermentation, more especially of those changes oc- 
curring in putrefaction and anaerobic fermentation, Hoppe-Seyler ( 217 ) 
in 1878, arrived at the notion that oxygen is rendered active through 
the agency of active (nascent) hydrogen, which in all processes of 
this kind appropriates to itself an atom of oxygen to form water, 
thereby leaving the other atoms of oxygen free or in the active condi- 
tion. Thus, 
h+h+o 2 =h 2 o+o 
and 
R + 0=RQ, 
where R represents a substance which can not ordinarily combine 
with molecular oxygen. In many processes of putrefaction and 
anaerobic fermentation, he observed that hydrogen is a constant 
product. Furthermore, he found it to be active, in the sense that it 
has the power of accomplishing the reduction of many substances not 
ordinarily reducible by molecular hydrogen. In other words, Hoppe- 
Se} r ler ( 217 ) assumes that the nascent hydrogen splits the oxygen 
molecule, forming water and liberating atomic oxygen, which can 
then combine with easilv oxidizable substances, or if no such, sub- 
stances be at hand, with water to form hydrogen peroxide, or with 
oxygen to form ozone, or with carbon monoxide to form carbon 
dioxide, as was shown by Baumann ( 39 ). 
In the field of pure chemistry many facts of similar import were 
already known, so that in seeking for an explanation of his own 
results, Hoppe-Seyler found many analogies to draw upon. For 
example, as early as 1853, Osann ( 314 , 315 , 316 ) had made the observa- 
tion that carbon and platinum which had been charged with hydrogen 
at the cathode in the electrolysis of dilute sulfuric acid, could effect 
the reduction of silver compounds in solution, etc., and somewhat 
later Beketoff ( 42 ) had shown that copper could be reduced from 
solutions of copper sulfate and silver from solutions of silver nitrate 
by passing hydrogen through such solutions containing a piece of 
