“from AIRTHREY. 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 fteam-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 takenup. 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 6.9 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. Tue three acid folutions being mixed together, no cloudi- 
nefs appeared, nor was any change produced; a proof that the 
ore contained no filver. 
»4. Tue 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; a proof that no arfe- 
nic acid was prefent. 
5. THE 
