Experiments- on Charcoal. 161 



v -Sulphurated hydrogen mixed with nitrous gas produces a 

 ft m liar eflfe&. 



This is the only experiment in which carburated fulphur 

 did not exhibit the fame phenomena as if it contained ful- 

 phura'ed hydrogen; and this fa& cannot certainly deftroy 

 the opinion which we formed, in confequence of all thofe we 

 have compared and repeated, in order to prove the difference 

 of thefe two bodies : befides, it is pothole that the colour 

 and vivacity of the flame may have arii'en from the fulphur, 

 which is a principle of both. 



If a piece of rag be dipped in liquid carburated fulphur 

 and wrapped round the bulb of a thermometer, and if the 

 evaporation be affifted by the wind of a bellows, it will make 

 the thermometer defcend to the freezing at leaft, that is to 

 lay, lower than ether under the fame circumftances. 



This fubftance unites with phofphorus, and diflblves with 

 great facility; but this folution is not more inflammable 

 than phofphorus alone. 



It unites alfo to a fmall quantity of fulphur without chan- 

 ging its ftate, only it becomes more coloured. 



It feems to have no acYion on charcoal. 



The water in which carburated fulphur condenfes during 

 its preparation acquires a greenifh -yellow colour, which in the 

 co'urfe of time becomes white and milky. At firft, this folu- 

 tion precipitates lead of a reddifh-brown colour, and then 

 black, as fulphurated hydrogen does ; and at length, after a 

 considerable time, white, like the fulphuric acid. It is to be 

 prefumed that the water in this cafe is decompofed. If this 

 a&ion of carburated fulphur on water is not very vifible, 

 it is the more fo when the water contains a fixed alkali; the 

 union takes place with difficulty even by heat; the carburated 

 fulphur traverfes the alkaline folution in vapours without 

 uniting fpeedily with it : however, if heated in a veflel almoft 

 clofe,in order to prevent the efcape of the carburated fulphur, 

 it diflblves almoft entirely, and nothing remains but a little 

 charcoal in the form of a black powder. This folution, when 

 recently made is of a dark amber colour, and difengages only 

 a very little fulphurated hydrogen by the addition of an acid ; 

 but at the end of fome time, and particularly when evapo- 

 rated, there is formed a great deal of fulphura ted hydrogen 

 and carbonic acid. The latter is fo abundant that the alkali 

 cryftallizes very eaflly. This phenomenon takes place in par- 

 ticular with foda. The reft of the folution is hydrogenated 

 fulphiiret, which precipitates folutions of lead of a beautiful 

 red colour. This precipitate, which becomes browner in the 



air, 



