Page:Vol 3 History of Mexico by H H Bancroft.djvu/608

588 beds proved to be fictitious. A number of simple stones, considered as precious by the Aztecs, enjoyed the same estimation among the conquerors until the fallacy became known, and since then nothing more has been heard of the supposed emeralds, rubies, and sapphires.

The mining region of New Spain covered in 1800 about 12,225 square leagues, including the northern provinces, and was divided into thirty-seven departments or diputaciones de minería, with about five hundred subdivisions or reales de minas, comprising approximately three thousand mines.

Taking as a guide the product of the different mines, those of Guanajuato, Catorce, in San Luis Potosí, and Zacatecas, rank as the most prominent, all of them situated between latitude 21° and 24°. The first had been discovered in the middle of the sixteenth century by muleteers trafficking between Zacatecas and Mexico, and the principal vein was struck in the shafts of Mellado and Rayas in 1558. The latter mine and the Valenciana take the lead in the district of Guanajato, where the yield, in the beginning of the century, formed about one seventh of the total for all America. Official returns place the aggregate product from 1701 till 1809 at 37,290,017 marks of silver, and 88,184 marks of gold, estimated at