The search for the precious metals had long shared with slave-hunting the efforts of the _Paulistas_ and others. Rumours of the existence of silver and gold had long excited the hopes of the Portuguese Government, and from time to time a stray specimen was procured from some unknown spot in the interior. But up to the close of the seventeenth century nothing was actually known as to the localities where the precious minerals were concealed. With the opening of the eighteenth century, however, a new era dawned upon _Brazil_; and the discoveries which were now about to be made were destined to determine the site of her future capital. In anticipation of the finding of gold and silver, a code of regulations had long since been issued relative to mines. Of the regulations in question, one provided that all persons in authority were bound to afford discoverers the necessary assistance; but when, about the middle of the seventeenth century, Marcos de Azevedo and a companion brought back from the _Rio Doce_ samples of silver and emeralds, the only result to the discoverers was that they were thrown into prison at _Bahia_ and detained there for life, because they obstinately refused to communicate the scene of their discovery to the Government. On their death renewed search was made for these mines, but in vain. A veteran, named Fernando Diaz, however, at the age of eighty, obtained permission to undertake a fresh search; and he explored the entire country now included in the captaincy of _Minas Geraes_, where he formed a number of settlements. The court of Lisbon had so often been excited by hopes which proved delusive, and so many searching expeditions had failed, that its patience was now exhausted. The old man, during four years, underwent a series of privations and hardships such as wore out his more youthful companions; but he was at length rewarded by his being shown by a young Indian the spot where emeralds were found. The explorer, however, did not live to return to _St. Paulo_, having been overtaken by a fever, which cost him his life. The first gold known to have been produced from this district was found about the year 1691, and in the following year an expedition was formed to explore the district (now called _Villa Rica_) where it had been found. Some further specimens having been obtained, they were exhibited at _Rio de Janeiro_ in 1693, in which year a commission was granted to one Carlos Silveria as _Capitam Mor_ of _Taboate_ and _Provedor_ of the royal fifths, with orders to establish a smelting-house in that town.