LEAD. — GOLD. 
47 
sulphuret of lead or Galena^ they are of great impor- 
tance. Lead is used, iu its metallic state, for the 
construction of aqueducts, covering the roofs of 
houses, the composition of amalgams, as pewter, 
&c. ; its oxides and salts are employed as paints, 
in the composition of glass, in medicine, and in 
several of the more common arts. Galena occurs 
both granular, compact, and crystallized, and is the 
variety which is so extensively worked in Missouri 
and other parts of the Union. 
Gold is only found in the native* state, though 
often alloyed with other metals. It is of a bright 
orange yellow, and does not tarnish on exposure to 
the air like iron pyrites. It is found in granite, 
quartz, slate, hornstone, sandstone, and limestone ; 
also in veins of iron ore, antimony, barytes, blende 
(zinc), and especially in alluvial soils. The gold 
of commerce is chiefly found in alluvial deposites, 
where it occurs in small particles or grains, called 
gold-dust. Thus the gold-mines of Brazil and Af- 
rica are entirely on the surface, the gold being sep- 
arated from the sand and gravel among which it is 
found by washing. In Brazil alone, according to 
Maowe, above 20 tons weight of gold ore is annually 
procured, which forms a large portion of the metal- 
lic circulation of the world. The gold-dust of Af- 
rica is an extensive article of commerce. 
Gold has sometimes been found in masses of con- 
siderable size. In 1730, a mass was found in Peru 
■weighing 45 pounds. In Paraguay, several masses 
have been found weighing from 20 to 50 pounds. A 
mass was once found in North Carolina, according 
to Cleaveland, which weighed 28 pounds. 
The gold-mines of the United States are chiefly 
confined to North Carolina, where they are spread 
over a space of not less than a thousand square 
* By this term is meant a state in which the metal is mallea-' 
ble or workable without refining or roasting. 
