DISOXIDATION EFFECTED BY THE ALKALINE PEEOXIDES. 
853 
That there are important differences in the reaction of the peroxide of barium and the 
peroxide of manganese is not to be denied. But these differences are perfectly con- 
formable to analogy, and are similar in kind to those which distinguish other chemical 
substances. For experience teaches us that no two chemical substances, however close 
may be the analogies which connect them, have identical chemical properties. Hydro- 
chloric acid has not all the properties of hydriodic acid ; soda has not all the properties 
of potash ; chlorine is not the same as iodine ; and sodium is different to potassium. Is 
it then to be a matter of surprise to us that peroxide of manganese has not all the 
properties of peroxide of hydrogen 1 is this case to have a special explanation 1 and are 
we to refer the different properties of these substances, not to the actual and known 
differences in the elements of which they consist, but to an altogether hypothetical 
and imaginary difference in the oxygen, which is the element common to the two bodies ? 
In each different compound, if such conventional language be admissible, oxygen has 
different properties ; and if we are to account for this class of differences by the assump- 
tion of different varieties of oxygen, Ave must assume not two forms only, but an infinite 
number of forms of that element. Of the precise mode in AA^hich the chemical pro- 
perties of the compound are connected Avith the chemical properties of its constituents, 
we are doubtless unable to gh'e an adequate account. But the fact of this connexion 
is not to be doubted. We take the oxygen of the peroxide of sodium, and transfer it 
to the protoxide of manganese. In this neAV combination it Avill no longer produce the 
effects of reduction. Again, Ave transfer the oxygen of the peroxide of barium to 
anhydrous acetic acid, and Ave form one of the most poAverful oxidizing agents with 
Avhich the chemist is acquainted ; Avhile Ave can re-transfer this oxygen to baryta, 
and restore to it its original properties. It is not the oxygen which is different, but 
the elements differ Avith Avhich the oxygen is associated. 
The definite manner in Avhich the final result is affected by modifying the conditions 
of the reaction, is rendered eA'ident by the following series of experiments. 
Peroxide of barium, treated Avith a concentrated solution of hydrochloric acid, evolves 
chlorine : with a dilute solution of hydrochloric acid, peroxide of hydrogen alone is 
formed. It was therefore probable that Avith hydrochloric acid of a certain degree of 
concentration both reactions would simultaneously occur. This is the case, and the ratio 
in which the tAvo reactions occur varies Avith the concentration of the hydrochloric acid, 
according to a definite laAV. 
A weighed quantity of peroxide of barium was placed in a small flask, to which a de- 
livery tube could be attached by means of a caoutchouc connector. The hydrochloric 
acid was poured cold upon the peroxide, the delivery tube attached, and the mixture 
vermag, und die zweite Gfruppe dadurch, dass keines Hirer Superoxyde unter irgend welchen TTmstanden 
aus der Salzsaure oder Irgend einem salzsauren Salze Chlor zu entbinden im Sfcande ist.” — Annalen der 
Chemie, vol. cviii. p. 167. This sweeping statement, in regard to which the truth could have been so readily- 
ascertained, is quite without foundation. 
MDCCCLXII. 6 A 
