We are now about to speak of metals, of actual wealth, the standard of comparative value, objects for which we diligently search, within the earth, in numerous ways. In one place, for instance, we undermine it for the purpose of obtaining riches, to supply the exigencies of life, searching for either gold or silver, electrum or copper. In another place, to satisfy the requirements of luxury, our researches extend to gems and pigments, with which to adorn our fingers and the walls of our houses: while in a third place, we gratify our rash propensit............