838 
PEOrESSOE B. C. BEODIE ON THE OXIDATION AND 
ssertion as to the molecular nature of water, we must, in consistency, make certain 
parallel assertions as to the molecular nature of oxygen. Our molecular hypotheses 
may change, but this relation will still remain. 
Views as to the polarization of oxygen, and the cause of the decompositions effected 
by the alkaline peroxides, which to a great extent are identical with the preceding, 
and in which the same language and the same notation are employed, have recently 
been put forward, with considerable pretension, as new and originating with himself, by 
ScHONBEiN, Professor of Chemistry at Basle*. This chemist can scarcely be aware of 
the memoir referred to, as in his numerous publications he makes no allusion to it. A 
reclamation of a priority of ten years ought not to be required, but I am compelled to 
call the attention of chemists to these circumstances in order that I myself may not 
be considered to appropriate without acknowledgment the ideas and discoveries of 
another. ‘ 
The decomposition of the alkaline peroxides by the oxide of silver and other similar 
bodies is complicated by the circumstance that not only is the peroxide decomposed by 
the metallic oxide, but the reduced silver, which is a necessary product of the action, 
and also probably the oxide of silver itself is capable of decomposing the peroxide by 
that continuous form of action which is spoken of as Catalytic. This interferes with 
the result ; the amount of oxygen evolved depends upon the relative velocity with which 
these two forms of decomposition occur ; and while the reduction in equal atomic pro- 
portions is never exceeded, and by certain modifications of the experiment may be very 
closely approximated to, it yet is never absolutely realized, for the catalytic action 
cannot be entirely eliminated. So that the total loss of oxygen from the oxide of silver 
in the experiment represents the relation which subsists between these two forms of 
decomposition, simultaneously occurring, and varies between the limits of the infinite, 
or catalytic action on the one hand, and the reduction in atomic proportions on the 
other. 
That this is the true account of the phenomena is seen from the fact that, where these 
distm’bing causes do not exist, the decomposition takes place in simple atomic propor- 
tions. This was shown to be the case in the decomposition of the peroxide of barium 
by iodine in the presence of water. The final result of this action is expressed by the 
equation 
I2 “h Ba2 O2 = 2 BaI -|- O2. 
It may be considered as taking place by the decomposition and re-formation of water, 
according to the two equations, 
I2 + Ba 2 O2 + H2 O = 2 HI + Ba 2 O + O2, 
2 HI + Ba2 O = 2 BaI -f H2 O. 
* See Aimalen der Chemie, vol. cviii. p. 157, Schonbeik, “ Ueber die gegenseltige Katalyse einer Eeibe 
Von Oxyden, Superoxyden und Sauerstoffsauren, &c.” Also see Phil. Mag. S. 4. vol. xyi. p. 178, Further 
Observations on the AEotropic Modifications of Oxygen, &c.” 
