LEAD. GOLD. 



47 



sulphuret of lead or Galena, they are of great impor- 

 tance. Lead is used, in 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. Tt 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. 



