The intendancy of Guancavelica is chiefly of note on account of the mercury mines it contains, there being only one silver mine of any importance. The quicksilver of Peru is only found near Valdivui in the district of Pataz, near the great Nevado de Pelagato; in the district of Conchucos, to the east of Santa; in the district of Huamalics, to the south-east of Guarachuco, at the Banos de Jesus; in the district of Guialas near Guaraz, and near Guancavelica; of all those places _Guancavelica_ is the only one which has ever produced that useful mineral in great abundance, the principal mine being situated in the mountains of _Santa Barbara_, south of the town of Guancavelica at the distance of more than a mile; it was discovered by the Indian Gonzalo de Abincopa, in the year 1567; but appears to have been known in the time of the Incas, who used cinnabar in painting themselves, and they are said to have procured it in this neighbourhood. The mine was opened in September 1570; it is divided into three stories, named _Brocal_, _Comedio_ and _Cochapata_, the last of which the government forbid to be worked, the bed containing red and yellow sulfuretted arsenic or orpiment, which was the cause of many deaths. This mine is free from water, and contains galleries cut in the solid rock at an immense expence. There has been extracted from it up to the year 1789, 1,040,452 quintals, or 136,573,162 pounds troy, being 4 or 6000 quintals annually; 50 quintals of tolerable mineral containing and yielding by distillation eight or twelve pounds of mercury. The cinnabar is found in a bed of quartz freestone of about 1400 feet in thickness, in strata and in small veins, so that the metalliferous mass averages only from 196 to 229 feet in breadth. Native mercury is rare, and the cinnabar is accompanied with red iron ore, magnetic iron, galena and pyrites, the crevices being frequently variegated with sulphate of lime, calcareous spar, and fibrous alum, and the bottom of the mine is 13,805 feet above the level of the sea. This mine employed seven thousand Peruvian camels, or alpacas, and llamas in carrying the ore to the furnaces of the town; which animals were governed by dogs trained for the purpose.