Obfervations on Lead Ore. 871 
continued fox' a longer time, the quantity of liquid would 
have been augmented. The liquid did not effervefce 
with either acids or alkalies; nor did it produce any 
change in the colour of blue paper, though I am certain, 
from experiment, that one drop of oil of vitriol, though 
diluted with two ounces of water, would have produced a 
^ v / # 
fenfible rednefs on the blue paper which I ufed. The 
liquid, notwithftanding, had an acid tafte, and a pungent 
fmell, refembling that of the volatile vitriolic acid. The 
experiment ought to be repeated with a larger quantity 
of ore, in order to afcertain the quantity and quality of 
the liquid, feparable therefrom by fimple diftillation. 
The black matter which had been fublimed into the 
neck of the retort, was examined with a microfcope, and 
it appeared to be pure lead ore; hence it is probable, that 
by a due degree of heat in clofe veflels, lead ore might 
be intirely fublimed without being decompofed; for the 
melted ore which was found at the bottom of the retort, 
had not any appearance of either fcoria, or of lead, upon 
its furface. Finding that fulphur could not be feparated 
from lead ore by diftilling it without addition , and yet being 
much difpofed to think, that it contained a confiderable 
portion of fulphur, I firft thought of diftilling it with 
charcoal duft, iron filings, fand, and other additions; but 
recollecting that fulphur might be feparated from anti- 
mony 
