MINERALOGY.--Gold, platina, silver, and brass, iron, pewter, lead, mercury, antimony, bismuth, amianthus, talk, calcareous stone, granite, black jasper marked with white; _amolar_, or grindstone, fossil-coal, saltpetre; white, red, yellow, grey, and black argils; diamonds, rubies, emeralds, chrysolites, topazes, sapphires, _aqua-marinas_, agates, amethysts, petrifactions, (_pingos d’agua_,) crystals, flintstone, and _pedra sabao_, of a pearl colour, very compact and heavy, but easily worked; images, candlesticks, and vessels by the turner are made of this stone. It affords excellent chalk, and its very fine dust is sought after by travellers. Many profound caverns and excavations are met with, from whence immense quantities of gold have been extracted. Some rocks are perforated from one side to the other; others have disappeared entirely, in the course of withdrawing their rich contents. Many mountains frequently reverberate, demonstrating that they are fully charged with minerals. A great number of torrents have been diverted, for a greater or less space, from their natural beds, to facilitate the extraction of gold and diamonds. ZOOLOGY.--All the species of Spanish domestic animals are bred here; the oxen and hog are the most numerous; the savage quadrupeds and birds met with in the adjoining provinces are common in this. The population principally consists of negroes, the property of the miner and the agriculturist. Indians exist only upon the eastern boundaries of the province. Many persons of all complexions are met with of the age of one hundred years. PHYTOLOGY.--The soil produces in abundance the first year; the second usually little, and in the third almost nothing; it is therefore requisite, according to the present mode of agriculture, to allow it to remain fallow for some years, until it is covered with a strong brushwood, which is then burnt down to form the first coat of manure.