cluding the loss of quicksilver, which, in 1826, was worth six reals per pound.
Nov. 15. We devoted the whole of this day to the Valenciana mine, it being impossible to form an idea, in less time, of the extent and importance of this vast undertaking. The history of the Valenciana, like that of the Biscaina Vein, was first made known to us by Humboldt, and is now almost forgotten; it may be advisable therefore to state that the mine is situated to the North of the town of Guănăjūātŏ, upon a part of the Vĕtă Mădrĕ, which, after being slightly worked towards the end of the sixteenth century, had been neglected as unpromising until the year 1760, when Mr. Ŏbrĕgōn, a young Spaniard of very small fortune, resolved to explore the vein upon one of those points where it was believed to be emborrascada, or destitute of mineral riches. For six whole years he continued to work upon this spot, with a perseverance which nothing but a presentiment that he was to make his fortune there can account for; and in 1767, having exhausted his own means, as well as the patience of those from whom he had occasionally obtained supplies, (Avios,) he entered into partnership with a shopkeeper of Rāyăs, called Ŏtērŏ, wielding with his own hands, it is said, the tools of the miner, until the year 1768, when the works having attained the depth of eighty metres, the vein suddenly began to produce enormous masses of rich ore; which continued to increase in value and extent to such a degree, that the profits
