This section is from the book "A Library Of Wonders And Curiosities Found In Nature And Art, Science And Literature", by I. Platt. Also available from Amazon: A library of wonders and curiosities.
There are great numbers of very rich mines which the waters of the ocean have invaded:. The disposition of the ground, which from the summit of the Cordilleras goes continually shelving to the South Sea, renders such events more common at Peru than in other places. This has been in some instances remedied. Joseph Salcedo, about 1660, discovered, near Puna, the mine of Laycacoto. It was so rich that they often cut the silver with a chisel. It was at last overflowed with water; but in 1740, Diego de Bacua associated with others to divert the springs. The labours which this difficult undertaking required, were not finished till 1754. The mine yields as much as it did at first. But mines still richer have been discovered; such as that of Potosi, which was found in the same country where the Incas worked that of Parco. An Indian, named Hualpa, in 1545, pursuing some deer, in order to climb certain steep rocks, laid hold of a bush, the roots of which loosened from the earth, and brought to view an ingot of silver. The indian had recourse to it for his own use. The change in his fortune was remarked by one of his countrymen, and he discovered to him the secret. The two friends could not keep their counsel, and enjoy their good fortune. They quarrelled; on which the indiscreet confidant discovered the whole to his master, Villaroel, a Spaniard. Upon this the mine was worked, and a great number of others were found in its vicinity, the principal of which are in the northern part of the mountain, and their direction is from north to south. The fame of Potosi 6oon spread abroad; and there was quickly built at the foot of the mountain a town, consisting of 60,000 Indians, and 10,000 Spaniards. The sterility of the soil did not prevent its being immediately peopled. Corn, fruit, flocks, American stuffs, and European luxuries, arrived from every quarter. In 1738 these mines produced annually near £978,000, without reckoning the silver which was not registered, and what had been carried off by fraud. From that time the produce has been so much diminished, that not above one-eighth part of the coin which was formerly struck, is now made. At all the mines of Peru, the Spaniards, in purifying their gold and silver, use mercury, with which they are supplied from Guanca Velica. The common opinion is, that this mine was discovered in 1564. The trade of mercury was then free; it became an exclusive trade in 1571. At this period all the mines of mercury were shut; and that of Guanca Velica alone was worked; the property of which the king reserved to himself. It is not found to diminish. The mine is du in the very large mountain of Potosi, sixty leagues from Lima. In its profound abyss are seen streets, squares, and a chapel, where the mysteries of religion on all festivals are celebrated. Millions of flambeaus are continually kept to enlighten it. The mine of Guanca Velica generally affects those who work in it with convulsions; and the other mines, which are not less unhealthy, are all worked by the Peruvians. These unfortunate victims of an insatiable avarice are crowded all together, and plunged naked into these abysses, the greatest part of which are deep, and all excessively cold. Tyranny has invented this refinement in cruelty, to render it impossible for any thing to escape its restless vigilance. If there are any wretches who long survive such barbarity, it is the use of cocoa that preserves them.