246 NATIVE etNNABAR. 



digested with muriatic acid ; the iron from the pyritous 

 particles ^as dissolved and the quartzQse gangue re- 

 mained. 

 Solution of the B' One lumdrcd and four grains of the mineraj, which 

 nic.allic part, (^qj,^ ^jje preceding experiment contained 100 grains of 

 pure cinnabar, Mere reduced to an extremely fine powder, 

 and put into 500 grains of muriatic acid (sp. grav. 1,125) 

 and heated : sulphurated hidrogen gas was disengaged. 

 Into the solution was poured drop by drop, 100 grains of 

 nitric acid (sp. grav. 1,235). Every time the acid was 

 added, there was an immediate effervescence. In this 

 manner the process was carried on till the decomposition 

 of the cinnabar, and the complete solution of the metallic 

 parts were effected. 



Combustion of ^^ f he sulphur that remained was of a greyish yellow 

 the sulphur. , ^.^ ^ . . , .. . i i , V « • 



colour and m some degree viscid : it weighed 11,8 grains. 



It was burned in a roasting test and left a blackish resi- 

 due of 1,5 grains, so that the contents of pure sulphur 

 were 10,3. 



c. The lively action of the nitric acid upon cinnabar, 

 gives reason to believe that part of the sulphur was con- 

 verted into sulphuric acid, by the oxigen of the decom- 

 posed nitric acid. 

 Deduction of In order to ascertain the quantity of sulphur which had 

 lulphur^whidi iindergone this change, the solution of the metallic part of 

 had been acidi- the cinnabar (which was of a yellow colour, on account 

 fied,andthence ^f j^Qn) ^as taken and decomposed by means of a solu- 

 of mercury and tion of muriate of barytes. The sulphate of barytes 

 sulphur in the which fell down, after having been ignited, weighed 30 

 grains ; which answers to 4,2 grains of sulphur. A small 

 quantity likewise escaped which has contributed to the 

 formation of sulphurated hidrogen gas; but as this quan- 

 tity did not exceed one fourth of a grain, we may conclude 

 that 100 parts of pure cinnabar contain 14,75 of sul- 

 phur. 

 Analysis in the C 1040 grains of the mineral, containing, according 

 drywayafFord- ^q ^Jj^ essay A, 1000 grains of pure cinnabar, were mixed 

 gult. ' with half their weight of iron filings, and distilled in a 



suitable apparatus: the mercury thus obtained, being 

 carefully collected weighed 845 grains, 



FroDi 



