10 
stance capable of causing the oxidation — as, for example, the conden- 
sation of oxygen upon platinum, whereby heat was liberated and the 
body (platinum) attained the temperature necessary to accomplish 
the oxidation. 
The discovery of ozone by Schoenbein ( 367 ) in 1840 and the finding 
of this remarkable substance among the oxidation products of readily 
oxidizable substances gave a new impulse to the study of oxidation 
phenomena and led ultimately to a more careful study of the whole 
subject of induced oxidations and of the phenomenon of oxygen 
carrying. This distinguished observer seems to have been the first 
to clearly recognize that in the final products of chemical combina- 
tion, particularly those in which oxygen is concerned, we see, as he 
put it, only the closing scene of a chemical drama which is in reality 
composed of several intermediate acts, and that for a correct under- 
standing of such processes it is quite as essential to know these 
intermediate acts as it is to know the beginning and the end. 
To the investigation of ozone and to the task of learning more of the 
initial and intermediate acts of the oxygen drama, Schoenbein set 
himself with remarkable assiduity and success. It is beyond the 
scope of this communication to attempt anything like a chronological 
account of the numerous investigations on the subject of ozone, which 
in themselves form one of the most interesting chapters in the history 
of chemical science. ( See Engler and Weissberg 164 .) It is sufficient 
to say in this connection that from the time of its discovery until its 
composition and nature were finally settled through the labors of 
Odling, Soret, and Andrews and Tait, Sclioebein himself held different 
notions at different times respecting its composition. As the net 
result of his many researches on the subject, Schoenbein came to look 
upon ozone and the ozonides as containing an atom of negatively 
polarized ox} i 'gen, which in its conduct toward oxidizable substances 
was far more active than oxygen in its ordinary form, and as we 
would interpret these phenomena at the present day, he accounted 
for its production from ordinary oxygen through the action of elec- 
tricity upon the supposition that as a result of the electrical discharge 
the ultimate particle (molecule) of oxygen is resolved into two atoms, 
one of which is negatively polarized and the other positively polarized, 
thus: 
(O) = © 4- 0 or, O 2 = © + O 
The negatively polarized atom them combines with a particle of 
ordinary oxygen to form ozone, O 2 0, whereas the positively polarized 
atom (antozone) combines with water to form hydrogen peroxide, 
H 2 0.©. These two substances, ozone and hydrogen peroxide, were 
regarded as the prototypes of a whole series of compounds to which 
Schoenbein gave the name ozonides and antozonides, respectively. 
