est stones, to 2,100 grains in the marc; and in the ores called "Guija de Oro," native gold is found disseminated in considerable quantities in the Quartz. I had an opportunity of observing in this mine, as well as in the Valenciana, the weight of the loads of ore brought up to the mouth of the shaft by the Tenateros, (carriers;) I saw myself loads of thirteen, fifteen, and one of sixteen and a half Arrobas, (325, 375, and 412½ English pounds,) delivered at the despacho, or receiving-rooms, by Indians, not distinguished by any appearance of extraordinary muscular strength, but inured from their infancy to this species of exertion, by which the muscles of the neck and back acquire a strength much beyond that possessed by any other member of the body.
Since its first discovery in 1556, Rayas appears, by the books of the proprietors, to have paid to the Provincial Treasury, as the King's fifth, the sum of 17,363,000 dollars. It has not yet nearly approached the depth at which the produce of the Veta Madre is supposed by Humboldt to become less valuable; and as a large tract of virgin ground will be laid open by the Tiro General, it may be considered almost as a new mine, with all the security for its future productiveness that an experience of three centuries can give. In the course of the present year, the works may be expected to be completed, and the company may then look for immediate and valuable returns.
The mine of Sĕchō was worked formerly without
