200^ Prof. Schoenbein on some Properties of Ozon'B*^ 



to mind certain acids and peroxides. Half the oxygen con- 

 tained in chromic acid exhiijits such a high degree of chemica^^ 

 excitement, tliat at the common temperature it sets on fire, . 

 not only aether and alcohol, but also ligneous substances, as 

 paper and wood ; whilst under the same circumstances, free 

 oxygen does not act at all, or at any rate very slowly upon" 

 the above substances. Nitric acid offers a similar instance; 

 and the peroxides of lead and manganese being put in contact 

 with a solution of indigo, destroy, like chlorine, that colour- 

 ing matter; and the same peroxides, when brought into the 

 presence of a solution of iodide of potassium, eliminate iodine^ 

 But the most striking instance of the exalted oxidifying power 

 of latent oxygen we have in ozone itself. The affinities of free 

 oxygen are generally called forth by the agency of heat, so 

 that at the common temperature even potassium is not acted 

 upon by oxygen, if the latter happens to be completely an- 

 hydrous. 



Starting from the hypothesis of BerthoUet, according to 

 which chlorine is composed of muriatic acid and oxygen, we 

 can easily conceive why chlorine at the common temperature 

 acts upon so gi'eat a number of oxidable substances. The 

 oxygen being latent in chlorine, is in a state of great chemical 

 excitement, similar to that in which the same element exists 

 in ozone, chromic acid, nitric acid, the metallic peroxides, 

 &c. ; and in which state oxygen is so very apt to unite, even 

 at the common temperature, with most of the oxidable mat- 

 ters. If these substances happen to be of such a kind as to 

 combine readily in their oxidized condition with the muriatic 

 acid of the older chemists, which is the case with hydrogen, 

 phosphorus, sulphur, and the greater part of the metals, 

 that circumstance must prove an additional reason why, in 

 most instances, oxymuriatic acid acts at the common tempe- 

 rature upon those bodies. There are two facts that have, as 

 already observed, much contributed to set aside Berthollet's 

 views, and gain to oxymuriatic acid the i-eputation of being a 

 simple body. Those facts are, the chemical inactivity exhi- 

 bited by chlorine towards carbon, and the discovery of cya- 

 nogen. As to the difficulty arising out of the first fact, it is 

 easily removed by admitting that anhydrous muriatic acid 

 unites only in one proportion with carbonic acid to form what 

 Davy called phosgene gas, and that there does not exist a 

 compound consisting of muriatic acid and carbonic oxide. 

 These suppositions, taken together with Berthollet's view, ac- 

 cording to which muriatic acid cannot be obtained in an iso- 

 lated state, satisfactorily account for the inactivity alluded to. 

 Giving anhydrous rnuriatic acid the sign M, we must consider 



