071 the Nature of certain Bodies. 407 



are less oxygenated. It may, -I know, be said, that it is 

 possible that they are merely combined with more hydrogen, 

 and that the sulphur in tliis state is analogous tothehydro- 

 genated sulphur of Berthollet, and to the alcohol of sulphur 

 of Lainp.idiiis. 



But whiin [decompounded dry sulphuret of potash by mu- 

 riatic acid, of the same kind as had been used for decom- 

 pounding the sulphuret of potassium, the substanceprodnced 

 seemed to be merely in that form, in which, according to 

 the able researches of Dr. Thomson, it is combined with 

 water; and notwithstanding the ingenious experiments of 

 M. A. Berthollet and M. Robiquct*, the nature of the 

 substance produced during the passage of sulphur over ig- 

 nited charcoal is far from being fully ascertained. In a 

 series of experiments, which my brother Mr. John Davy 

 had the goodness to undertake, at my request, in the labo- 

 ratorv of the I^oyal Institution, on the action of sulphur 

 On charcoal, the products were found to be very ditferent, 

 according as the charcoal employed differed in its nature. 

 ?n an iiistance, in whicli imperfectly made charcoal was 

 empiovcd, the liquor that passed over ]e\'t by combustion a 

 residuunj that h-Tl all the properties of carbonaceous matter; 

 which agrees with the observations of MM. Desormes and 

 Clement ; but when the charcoal had been well burnt, there 

 was no such residuum produced. It was found, that the 

 same charcoal might be cmi)loved in a number of processes 

 till it was nearly entirely consumed, and that the sulphur, 

 not rendered litjuid, might be used for several operations. 

 In all cases mixtures off sulphuretted hydrogen gas and 

 hydrocarbonate v»'ere evolved. 



I particularly examined a specimen of the liquor which 

 had been obtained in the last process from charcoal that had 

 been often used. It was a non-conductor of electricity, and, 

 when the Voltaic spark was taken in it, did not evolve gas 

 with more rapidity than sulphur; and this gas proved to be 

 sulphuretted hydrogen. 



Supposing the liquor to contain hydrogen in considerable 

 quantities, I conceived that it must be decomposed by oxy- 

 muriatic acid ; but it merely absorbed this substance, de- 

 positing crystals of common sulphur, and becoming a 

 fluid siuular to the sulphuretted muriatic acid ; though when 



♦ Aimnln de ChimU, 1807, page 14-1, 148. 



t Fivo meaiurcs of the mixed ^Hfi, aj^itated with solution of potash, left a 

 rcMdiiiim of '.i 5. These were deton:Kcd with rro of oxygen ; the wliole di- 

 rninutioii »va^ to C, of this residuum 'i-Ti appeared to be carbonic acid. 



C c 4 water 



