Dr Davy's Observations on Euchlorine. 5 1 



disengaged, with the occasional aid of a gentle heat, and collect- 

 ed in different receivers over mercury. After standing twenty- 

 four hours, there was very little absorption of gas. It possessed 

 all the characters of euchlorine, as described by my brother : ori 

 agitating it, and transferring it from one receiver to another, the 

 effects were different ; sometimes it appeared to be pretty rapid- 

 ly absorbed, at other times very slightly, or, indeed, hardly per- 

 ceptibly, the surface of mercury retaining its lustre. The drier 

 the mercury was, and the vessels, the less tendency there was to 

 absorption. In some experiments, by repetition of transfers of 

 the same portion of gas in mercury not carefully dried, the 

 whole was absorbed ; and, in other experiments, stopt, when 

 about half the volume of the gas was absorbed. The residue had 

 less intensity of colour, coloured water less strongly when ab- 

 sorbed by it, and had ceased to be explosive on the application 

 of heat. The compound formed in the jars was bulky, of a 

 darkish-gray hue, and had somewhat the appearance of an amal- 

 gam. I could obtain no euchlorine from it, either by the action 

 of heat or of acids ; it soiled the fingers like black oxide of mer- 

 cury, and appeared to consist of calomel, corrosive subhmate, 

 and this oxide of the metal. 



The inference I drew from the experiment was, that euchlo- 

 rine may remain in contact with dry mercury without altera- 

 tion ; and that, when it is absorbed, it is in consequence of its 

 decomposition, the liberated oxygen combining with the mercu- 

 ry at the same time that the chlorine did. 



These results may tend to reconcile the apparently contradic- 

 tory statements of my brother and of M. Soubeiran. The for- 

 mer using dry mercury, and making his experiments, as well as 

 I recollect, at a cold season of the year, and being chiefly intent 

 on procuring the gas as pure as possible, for examination, was 

 most struck by its want of action on mercury, and justly so. M. 

 Soubeiran, on the contrary, viewing the gas as a mixture of 

 chlorine, and deutoxide of chlorine, rather looked for its absorp- 

 tion. He supposes that its action on mercury, '« a echapp^ k 

 H. Davy, sans doute parce que le protoxide de chlore pent etre 

 conserve assez long- temps sur le mercure a la faveur de la croute 

 superficielle qui recouvre bientot le metal, et le preserve d'une 

 alteration plus profonde :'' An explanation hardly to be admit- 



D 2 



