Almadén: the mercury of the Indies, and the ledger its own state kept

The oldest known mercury mine in the world became, after about 1550, the European supply for a Mexican invention: Bartolomé de Medina's silver amalgamation. By 1861 a Spanish government memoir could argue that almost the whole consumption of Almadén's quicksilver was the treatment of American silver ores by the patio system. The same memoir prints the miners' hospital returns for 1844–1855 and the physician's account of what mercury did to the men.