274 Klaproth on the Chemical Analysis 



riferous titanium, and some small particles of sulphur, which 

 burned away with a blue flame. The muriatic solution when 

 cold, was duly diluted and precipitated by carbonate of soda ; 

 the precipitate, collected, dried, and ignited, gave 139 grains of 

 oxide of iron. The remaining fluid boiled with excess of car- 

 bonate of soda afforded a trace of oxide of manganese: 100 

 parts of this ore therefore contain, 



Silver 14, 



Brown oxide of iron . . .71. 



Silica 3.50 



Sand, §-c 1. 



Water 8.50 



98. 



Chemical Analysis of the Hepatic Mercurial Ore from Idria. 



The specimen employed in the following analysis was com- 

 pact, and its colour intermediate between cochineal red and lead 

 grey; it is opaque, gives a dark red streak, and acquires a shining 

 surface when rubbed ; it is soft, tasteless, and of a specific 

 gravity=7.100 It is susceptible of a bad polish, and then ap- 

 pears of a liver brown colour. 



A. 1000 grains of this ore, distilled with half its weight of 

 iron filings, gave 818 grains of pure mercury. The residuary 

 sulphuret of iron was mixed with a black powder. 



B. a. lUO grains of the ore in fine powder were boiled with 

 500 grains of muriatic acid, which occasioned the evolution of 

 sulphuretted hydrogen: 100 grains of nitric acid were then 

 gradually added, by which the whole of the ore was dissolved 

 with the exception of a black residue of 10 grains; this re- 

 sidue was carefully heated upon a porcelain capsule, so as to 

 burn away the sulphur only : there remained three grains of 

 carbonaceous matter, which, when more strongly ignited, left 

 one grain of red ash. 



b. The above nitromuriatic solution was precipitated by mu- 

 riate of baryta, and the sulphate of baryta thus produced weighed 

 after ignition 46.5 grains, whence it appears that 6.5 grains 



