PACHUCA

in full Pachuca De Soto, capital city, Hidalgo estado (state), east-central Mexico. It was one of the first settlements in New Spain and lies in a rich mining district in the Sierra Madre Oriental, 7,959 feet (2,426 m) above sea level. Its first silver mine was discovered in 1534, though it is said that some of the mines were known to pre-Columbian Indians. The nearby Real del Monte mine, begun in 1739 and still in operation, is one of the most extensive mining properties in the world. The patio, or Mexican, process of separating silver from the ore by amalgamation with mercury was perfected in Pachuca by Bartolom de Medina in the 16th century, and the Pachuca tank used in the cyanide process was developed there in the 20th century. The government has sought to counteract declining mineral production by increasing industrialization. Industries include smelting works and numerous metallic-ore reduction plants. Pachuca has a school of mines and metallurgy, founded in 1877, and it houses the Autonomous University of Hidalgo (1961). Pop. (1980) 110,351.