443 Prof. Schonbein on the Connexion of 



in contact with a number of inorganic and organic substances. 

 Phosphorus, as need scarcely be mentioned, is especially distin- 

 guished among inorganic substances. When shaken in a finely- 

 divided condition with atmospheric air and solution of indigo, 

 the latter is decomposed with tolerable rapidity at ordinary tem- 

 peratures, and very rapidly at a somewhat higher temperatiu'e. 



We are no longer surprised at this action ; for we know now, 

 that under these circumstances phosphorus ozonizes atmospheric 

 oxygen; and the decomposition of the indigo solution can be 

 eflPected even without the presence of phosphorus, that is, by 

 first leaving atmospheric air for some time in contact with phos- 

 phorus, then removing the phosphorus, and shaking the air thus 

 treated with the tincture of indigo. It is scarcely necessary to 

 say that this action is produced by the oxygen allotropized by the 

 phosphorus. 



Among organic substances, the camphene oils and common 

 aether ai'e similar in their comportment to phosphorus ; with 

 this difference, however, that these substances act less power- 

 fully than the latter body, and that their activity is essentially 

 increased by light, while that of phosphorus appears to be wholly 

 independent of this agent. This chemically exciting influence 

 is conveniently proved with water which has been coloured blue 

 by solution of indigo, and which^is brought in contact with oil of 

 turpentine, or sether free from O. Under these circumstances 

 the coloured water becomes decolorized, and in the light with 

 greater rapidity than in the dark. 



Similar results are obtained if the diluted solution of indigo is 

 mixed with spirit of wine, wine, beer, wood-spirit, tartaric acid, 

 oleic acid, linseed oil, &c., and exposed to the action of air under 

 the influence of light, from which it is clear that these substances 

 also possess the property of inciting to oxidize dissolved indigo 

 toisatine, that is, of transforming it into O. 



That the latter substances have themselves undergone an oxi- 

 dation by the oxygen which they have modified, in consequence 

 of the oxidizablity of their constituents, is just as self-evident 

 as that oxygen ozonized by phosphorus unites with that body to 

 form phosphorous acid. It would therefore, I believe, be an in- 

 coi'rect view were we to regard the oxidation of oil of turpentine, 

 of tartaric acid, &c., as the immediate cause of the oxidation of 

 indigo-blue. The ozonization of common oxygen must precede 

 both acts of oxidation, and hence these do not follow each other, 

 but are simultaneous. 



I must mention here the remarkable compounds of the alcohol 

 radicals with metallic bodies, which are distinguished by their 

 high degree of oxidizability. Stibsethyle, cacodyle, &c. take fire 

 even at ordinary temperatures ; and they also, in contact with 



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