88 Transactions of the 



Similarly, potassic permanganate (KMnOj and peroxide 

 of hydrogen (H2O2) evolve oxygen, and Lydrated peroxide of 

 manganese (MnHgOa) is precipitated ; also chromic acid 

 (H2CrOJ, sulphuric acid (H^SOg), and peroxide of hydrogen 

 (H2O2) give off ordinary oxygen with the production of 

 chromic sulphate (Cr23S04) ; and again argentic oxide 

 (AggO) is reduced to the metallic state by peroxide of 

 hydrogen. Thus : — 



Ag^e + HjG © = Ag2 + © + ii„e 



Such peculiar reactions are not characteristic of hydroxyl 

 (H2O2) only ; many other peroxides exhibit the same pro- 

 perties, viz., those of the alkalis, alkaline earths, &c. It is 

 assumed that these reactions are due to the tendency to 

 union between the two different modifications of oxygen 

 contained in the substances brought into contact, it being 

 supposed that the principle of ozone (0) is present in per- 

 manganic and chronic acids, and in barium dioxide, while 

 that of antozone (©) is in the peroxides of hydrogen, man- 

 ganese, &c. The following reactions Schonbein thought 

 confirmatory of his theory : — 



Baric dioxide (Ba02), when acted on by hydrochloric acid 

 (HCl), forms baric chloride (BaCl2) and peroxide of hydrogen 

 (H2O2), but when hydrochloric acid acts upon manganese 

 dioxide (MnOj), the hydrochloric acid is decomposed, and 

 chlorine evolved. Thus : — 



(1) BaO. + SHCUHjO^ + BaCU 



(y) MnO^ + 4HC1 = OI3 + MnClj + 2R^0 



And again, when sulphovinic acid (C2HgS04) is heated in the 

 presence of baric dioxide (BaOj), ether (C^HjqO), bicarburet 

 of hydrogen (C4H2), and sulphuric dioxide (SO2) are the 

 produce, biit the substitution of manganic dioxide (Mn02) 

 for baric dioxide results in the production of aldehyde 

 (C^O). 



Nevertheless, hydroxyl can be prepared from both manga- 

 nese and baric dioxides, but each hydric dioxide so produced 

 is decomposed by the peroxide employed to form the other, 

 .and they wUl also decompose each other. 



Von Babo's experiments appear to indicate that Schon- 

 bein' s antozone is peroxide of hydrogen. 



Sir B. C. Brodie has objected to this complicated theory of 

 the existence of two opposite corresponding modifications of 

 oxygen — ozone and antozone, but explains these decomposi- 

 tions by reference to the general laws of chemical change. 

 He says (P/a7. Trans. 1862, p. 852), ' No such fundamental 



