25^3 Prof. Schonbein on the Connexion of 



Similar to this salt iu its comportment is peroxide of hydrogen, 

 which shows a perceptible increase of temperature on its resolu- 

 tion into water and common oxygen. And the surprising phseno- 

 raenon, that the oxides of the noble metals, in catalysing peroxide 

 of hydrogen, are themselves decomposed into metal and oxygen, 

 might be ascribed, at least partially, to the heat which becomes 

 free in consequence of the decomposition of HO^. The circum- 

 stance, however, that many of the substances which convert 

 free O into 0, or catalyse peroxide of hydrogen and chlorate of 

 potash, are oxygen compounds which themselves contain O, ap- 

 pears to allow the assumption that the combined O^ of certain 

 substances possesses the property of changing the Oof certain 

 other compounds into 0, undergoing in general themselves the 

 same change of condition, so that many compounds containing 

 O can mutually catalyse each other. MnO + O and HO + both 

 lose oxygen by mutual contact ; and the temperature at which, 

 under these circumstances, is disengaged from peroxide of 

 manganese, is perceptibly lower than that at which this peroxide 

 of itself disengages oxygen. 



By using for catalysis peroxide of hydrogen strongly diluted 

 with water, the action may take place so slowly that the tem- 

 perature of the mixture during the decomposition of the HO^ is 

 very inconsiderably raised ; and yet experience teaches that even 

 under these circumstances the oxides of the noble metals are 

 reduced, and the peroxides of lead, manganese, &c. give off a 

 part of their oxygen in the condition. These facts show that 

 in the catalysis of peroxide of hydrogen, the oxide of gold, oxide 

 of silver, peroxide of lead, &c. are decomposed not only by the 

 heat, but by the deozonizing influence M'hich the of the HO + O 

 exercises on the associated with the gold, sdver, or protoxide 

 of lead. Only when concentrated peroxide of hydrogen is cata- 

 lysed, can a part of the oxide of gold, &c. used for this purpose 

 be decomposed, in consequence of the strong disengagement of 

 heat Avhieh takes place under these circumstances. 



In respect to the subject of our discussion, the different oxides 

 of chlorine possess a special interest, on which account we will 

 submit them to a closer consideration. 



These compounds, as is well known, are distinguished by their 

 powerful oxidizing properties ; and it is also a fact, that none of 

 them are produced by the direct union of chlorine and common 

 oxygen, any more than peroxide of hydrogen can be formed by 

 the direct union of water and O, a further reason why I assume 

 that the oxygen of the said compounds exists in the condition. 

 But it would also follow, if this supposition be correct, that the 

 oxides of chlorine must be^ catalysed by all the agents which are 

 capable of converting the of these compounds into 0. 



