30 
Copper, 
a variety of ores from different places and of different spe- 
cies are brought to the same smelting-house (which is the 
case in many of the houses at Swansea and different parts 
of the Bristol coast) much technical judgment is exercised 
in sorting the ores and distributing the charges for the 
furnace in such a manner that the more fusible will assist 
the reduction of the refractory, and the poorer will be 
made more worth working by the addition of a portion of 
the richer ores, and the like. 
The subsequent operations whereby the ingots or pigs 
of malleable copper are formed into sheet copper, wire, 
nails, bolts, cauldrons, and an infinite variety of manu- 
factured articles* do not come within the province of pure 
chemistry : it may be sufficient to observe that the ham- 
mering renders the metal much more uniform, close, and 
ductile, but this requires to be frequently alternated with 
annealing at a full red heat, to prevent the metal from 
cracking under the powerful pressure to which it is ex- 
posed. Immediately after the last annealing, the copper 
plates are quenched in urine, which somewhat hardens the 
surface, and gives it that redness which is considered by 
the merchant as one mark of the purity of the metah 
In the reduction of the copper ores of Neusol in Hun- 
gary, lead is used in the refining part of the process* in 
the following manner : the rough copper is spread on the 
bed of a furnace, and when it has been six hours in fu- 
sion, some lead, in the proportion of from 6 to 8 per cent* 
of the copper, is thrown in, which immediately begins to 
vitrify and to form a thick scoria along with the impuri- 
ties of the copper, which is scummed off successively till 
the whole is exhausted and the copper remains fine and 
clear. This process lasts from ten to twelve hours, with 
fifty quintals of raw copper. The scorise retain a portion 
of copper, which makes it answer to work them again. 
* Jars Voyages MetalL tom, 3s. 
