23 
lead to the amount of 912 tons was prepared in 1807. A 
few years will probably accommodate the supply to the de¬ 
mand. At present, the metal, tog-ether with its manufac¬ 
tures, and red and white lead, are imported to the amount 
of 2,375 tons, although the two latter articles are manufac¬ 
tured in considerable quantities in this country.* 
Various species of lead ore have been discovered, such as 
the molybdate , (yellow lead ore) sulphate , (lead vitriol) and 
muriate off lead (Kidd) at Northampton,§ and the phosphate 
of lead (green lead ore) at Perkiomen,f but the common 
ore found, and indeed the only one worked as an article of 
commerce and manufactures, is the sulphuret of lead ov ga¬ 
lena. After roasting it to expel the sulphur, it is mixed 
with charcoal, and reduced in a furnace. Silver which is 
an important result, is obtained by cupellation ; and the 
oxyd which remains in the form of a semivitrified mass, is 
stiled litharge , a substance used together with minium* 
masicot, and ceruse, (all oxides but of different colours)|{ by- 
painters, potters and glass workers. 
The principal manufactures of lead are those of shot, and 
of painter's colours. The former are prepared by pouring* 
the melted metal from a great height, and afterwards sorted 
by passing them through seives of various sized holes. The 
establishments for this purpose, at Philadelphia and in Lou¬ 
isiana, are said to yield 600 tons annually, sufficient for the 
late demand. It has now, since the declaration of war, in¬ 
creased, and thus offered a new argument for exploring and 
working our lead mines. 
Painter’s colours are prepared in several places. Besides 
these, lead is formed in sheets for the covering of houses, 
and into doer and window weights, and alloyed with copper, 
forms what is styled pot metal. 
Mineralogists have generally divided their kingdom into 
four classes. Metals ; Infammable Fossils; Saline Sub- 
* Gallatin’s Report. § By Dr. William Meade, Bruce 3, 149. 
X- By Mr. Godon (Bruce 1, 30.) 
|| Minium , red ; massicot y yellow ; ceruse, white; litharge » 
reddish yellow, or orange. Minium is used in making flint glass, 
and for the glazing of potterv. 
C 
