CHAPTER XV.

Nature and Character of Mineral Veins—Metalliferous Deposits— Mines—Their Drainage and Ventilation—Their Depth—Diffusion of the Metals—Gold—Silver—Lead—British Mines—Quicksilver—Copper—Tin— Cornish Mines—Coal—Iron—Most abundant in the Temperate Zones, especially in the Northern—European and British Iron and Coal— American Iron and Coal—Arsenic and other Metals—Salt—Sulphur— Diffusion of the Gems 168