324 ANALYTICAL EXPERIMENTS ON SULPHU1. 



Attempt to as- The oily substances in combustion produce two or three 

 certain whether f j mes their weight of carbonic acid and some water. I 

 sulphur form '*»•** 



water by burn- endeavoured to ascertain, whether water was formed in the 



tag in dry combustion of sulphur in oxigen gas, dried by exposure to 



potash ; but in this case sulphureous acid is produced in 

 much larger quantities than sulphuric acid, and this last 

 product is condensed with great difficulty. In cases, how- 

 ever, in which I have obtained, by applying artificial cold, 

 a deposition of acid in the form of a film of dew in glass 

 retorts out of the contact of the atmosphere, in which sul- 

 phur had been burned in oxigen gas hygrometrically dry, it 

 has appeared to me less tenacious and lighter than the com- 

 mon sulphuric acid of commerce, which in the most con- 

 centrated form in which I have seen it, namely, at 1*855, 

 gave abundance of hidrogen as well as sulphur at the 

 negative surface in the voltaic circuit, and hence evidently 

 contained water. 

 Reddening of The reddening of the litmus paper, by sulphur that had 

 the litmus been acted on by voltaic electricity, might be ascribed to its 

 sulphuretted containing some of the sulphuretted hidrogen formed in the 

 fttdrogen. process ; but even the production of this gas, as will be 



immediately seen, is an evidence of the existence of oxigen 

 in sulphur. 

 Fotassiumhcat- la my early experiments on potassium, procured by elec- 

 edin«*J- tricity, I heated small globules of potassium in large quan- 



hidrogen. titie* of sulphuretted hidrogen, and I found that sulphuret 



of potash was formed; but this might be owing to the 

 water dissolved in the gas, and I ventured to draw no con- 

 clusion till I had tried the experiment in an unobjectionable 

 manner. 

 Perfectly dried, * heated four grains of potassium in a retort of the capa- 

 city of twenty cubical inches ; it had been filled after the 

 usual processes of exhaustion with sulphuretted hidrogen, 

 dried by means of muriate of lime that had been heated to 

 whiteness; as soon as the potassium fused, white fumes 

 took fire were copiously emitted, and the potassium soon took fire, 



and burnt with a most brilliant flame, yellow in the centre 

 and red towards the circumference *. 



. The 



* In the Moniteur, May 27, 1808, in" the account of M. M. 



pay-Lussac and Thenard's experiments, it is mentioned, that 



potassium 



