m 
Lead . 
have been saved* if the fire had at first been kept so gen- 
tle as to have allowed twelve hours for finishing the ope- 
ration. 
Sulphur cannot be separated from lead ore in close ves- 
sels, and the lead ore melts with so small a degree of heat* 
that there may be more difficulty in procuring the sul- 
phur from the ores of lead, than from those of copper or 
iron, however, I am far from thinking the matter imprac- 
ticable, though I have not yet hit upon the method of do- 
ing it ; and the following reflections may, perhaps, tend 
to supercede the necessity of collecting the sulphur in 
substance. 
When it is said that the sulphur is consumed by the 
flame of the furnace as soon as it is separated from the ore, 
the reader will please to recollect, that sulphur consists of 
two parts,— of an inflammable part, by which it is rendered 
combustible,— and of an acid part, which is set at liberty* 
in the form of vapour, during the burning of the sulphur. 
Now this acid, though it may be driven out of the furnace 
in the form of a vapour, yet it is incapable of being there- 
by decomposed ; it still continues to be an acid ; and, 
could the vapour be condensed, might answer all the 
same purposes as the acid of vitriol ; since all the acid 
of vitriol, now used in commerce, is actually procured 
from the burning of sulphur. That the fact, with respect 
to the acid not being decomposed, is as I have stated it, 
may be readily proved. The smoke which issues out of 
the chimney for some hours after each fresh charge of ore, 
has a suffocating smell, perfectly resembling the smell of 
burning brimstone ; and if a wet cloth, or a wet hand, be 
held in it for a very short space of time, and afterwards 
applied to the tongue, a strong acid will be sensibly per- 
ceived. Various methods may be invented for condens- 
ing this acid vapour, and, probably, more commodious 
than the following one, which, however, I will just take 
