on the Nature of certain Bodies. IS 



transparent when fluid, and scmi-transparenl when solid, 

 and highly retractive ; their affections by electricity are like- 

 wise similar to those of sulphur ; for the oily bodies give out 

 hydrocarbonate by the agency of the Vohaic 6pail<, and be- 

 come brown, as if from the deposition of carbonaceous 

 matter. 



But the resinous and oily substances are compounds of a 

 small quantity of hydrogen and oxygen, with a large quan- 

 tity of a carbonaceous basis. The existence of hydrogen in 

 sulphur is iuHy proved, and we have no right to consider a 

 substance, whicli can be produced fronj it in such large 

 quantities, merely as an accidental ingiedient. 



The oily substances in combustion, produce two or three 

 times their weight of carbonic acid and some wafer; I en- 

 deavoured to ascertam whether water was formed in the 

 combustion of sulphur in oxva;en gas, dried by exposure to 

 potash; but in this case sulphureous acid is produced ia 

 much larger quantities than sulphuric acid, and this last 

 product is condensed with great difficulty. In cases, however, 

 in which I have obtained, by applymg artificial cold, a depo- 

 sition of acid in the form of a film of dew in glass retorts out 

 of the contact of the atmosphere, in which sulphur had been 

 burned in oxvgen gas hygrometrically dry, it has appeared 

 to me less tenacious and lighter than the common sulphuric 

 acid of commerce, which in the most concentrated form in 

 which I have seen it, namely, at 1-853, gave abundance of 

 hydrogen as well as sulphur, at the negative surface in dm 

 Voltaic circuit, and hence evidently contained v>atcr. 



The reddening of the litmus paper, by sulphur that had 

 been acted on by Voltaic electricity, might be ascribed to its 

 containing some of the sulphuretted hydrogen formed in the 

 process ; but even the production of this gas, as will be im- 

 mediately seen, is an evidence of the existence of oxygen ia 

 si^iphur. 



In my early experiments on potassium, procured by elec- 

 tricity. I lieatcd small globules of potassium in large quari- 

 .fi{ics of sulphuretted hydrogen, and I found that sulphurct 

 ttt" potash 'va? fprmtd ; but this mi^Ut be owing to the water 



dJs;5olvcd 



