The Wealth of Nations by Part 4 Chapter 7 Page 25

The quantities of those metals which the first adventurers are said to have found there had probably been very much magnified, as well as the fertility of the mines which were wrought immediately after the first discovery. What those adventurers were reported to have found, however, was sufficient to inflame the avidity of all their countrymen. Every Spaniard who sailed to America expected to find an Eldorado. Fortune, too, did upon this what she has done upon very few other occasions. She realized in some measure the extravagant hopes of her votaries, and in the discovery and conquest of Mexico and Peru (of which the one happened about thirty, the other about forty years after the first expedition of Columbus), she presented them with something not very unlike that profusion of the precious metals which they sought for.