HEPATIC MERCURY. 231 



this mixed mineral. By shewing that the sulphur is com- Analjrsis of the 

 bined Avith the metal in the same proportion as in cinna- hepatic^ ore of 

 bar, namely as 1 to 6 in round numbers, we are taught 

 liow little foundation there is for the opinion of thosi 

 who, like Sage and.Kirwan, think that a part only of the 

 mercury is in the state of sulphurated mercury, and that 

 the other is in the state of a simple oxide. If that were 

 the case, the non-sulphurated part would certainly be 

 soluble in the nitric acid. Experiment shews that this is 

 not the case, because the acid cannot dissolve any part, 

 even when boiling, the mineral powder remaining un- 

 changed at the bottom of the vessel. This opinion has 

 perhaps been taken up from observing that in sublima- 

 tion a part only of the mineral rises ia the state of cin- 

 nabar, while the other passes in the form of fluid mer- 

 cury. But this arises from the presence of charcoal 

 among its ingredients, which decomposes cinnabar at an ^ 



elevated temperature : whether it be that the carbon 

 takes from the mercury the minimum of oxygen neces- 

 sary to the formation of cinnabar, or whether it be that 

 the sulphur which combines at an high temperature with 

 the carbon, and forms carbonated sulphur, is put into a 

 state in which it cannot combine chemically with the 

 mercury. The facts shew that it is really so ; for having 

 as a direct proof sublimed artificial cinnabar with lamp 

 black, the greatest part of the cinnabar was decomposed 

 in the same manner as the hepatic mercury, and the re- 

 sult was a mixture of Ethiops mineral and globules of 

 metallic mercury. 



As an observation on the state in which mercury ex- 

 ists in cinnabar, I shall add that the antient opinion that 

 it has the state of a perfect oxide cannot be maintained 

 from th« proofs which have been given by Proust, Bu- 

 cholz, and others. 



But does cinnabar absolutely contain no oxigen ? and 

 is the mercury in the metallic state ? For my part, I 

 think the question requires to be examined more exactly. 

 From the appearances it seems that the mercury must 

 exist in cinnabar at a very low degree of oxidation ; 

 which on that account has not yet been examined by 

 observers. On this question, respecting which the pre- 

 Hh^ sent 



