from AIRTHRET. 265 



each other. Streak fimilar, opake, brittle, eafily frangible; 

 fpecific gravity 4.878. 



1. To free the ore as completely as poflible from foreign 

 matter, it was reduced to a coarfe powder, and carefully pick- 

 ed. It was then digefted in diluted muriatic acid, which dif- 

 folved a quantity of carbonate of lime, amounting to 13 per 

 cent, of the original weight of the ore. 



2. Thus purified, it was dried on the fleam-bath, and 100 

 grains of it were reduced to a fine powder, and digefted in di- 

 luted nitric acid, till every thing foluble in that menftruum 

 was taken up. The refidue was digefted in the fame manner, 

 in muriatic acid; and when that acid ceafed to act, the refidue 

 was treated with nitro-muriatic acid till no farther folution 

 could be produced. The infoluble matter was of a white co- 

 lour ; it weighed 6,g grains, and was almoft entirely fulphate 

 of barytes. No traces of fulphate of lead, nor of oxide of anti- 

 mony, could be detected in it by the blow-pipe. 



3. The three acid folutions being mixed together, no cloudi- 

 nefs appeared, nor was any change produced ; a proof that the 

 ore contained no filver. 



4. The folution being evaporated nearly to drynefs, was di- 

 luted with water, and precipitated by muriate of barytes. By 

 this means, the fulphuric and arfenic acids, which had been 

 formed during the long-continued action of the nitric acid on 

 the ore, and the prefence of which had been indicated by re- 

 agents, were thrown down; for nitrate of lead, added to the re- 

 fidual liquid, occafioned no precipitate j a proof that no arfe- 

 nic acid was prefent. 



5- The 



