The most precious and useful of the metals lie, in many places, so near the earth’s surface that, in the earliest times, mining is unneeded and therefore unpractised. We are told that in Spain silver was first discovered in consequence of a great fire, which consumed all the forests wherewith the mountains were clothed, and lasted many days; at the end of which time the surface of the soil was found to be intersected by streams of silver from the melting of the superficial silver ore through the intense heat of the conflagration. The natives did not know what to do with the metal, so they bartered it away to the Phoenician traders, who already frequented their country, in return for some wares of very moderate value.[101] Whether this tale be true or no, it is certain that even at the present day, in what are called “new countries,” valuable metals often show themselves on the surface of the soil, either in the form of metalliferous earths, or of rocks which shine with spangles of a metallic character, or occasionally, though rarely, of actual masses of pure ore, sometimes encrusted with an oxide, sometimes bare, bright, and unmistakable. In modern times, whenever there is a rush into any gold region--whether California, or Australia, or South Africa--the early yield is from the surface. The first comers scratch the ground with a knife or with a pick-axe, and are rewarded by discovering “nuggets” of greater or less dimensions; the next flight of gold-finders search the beds of the streams; and it is not until the supply from these two sources begins to fail that mining, in the proper sense of the term, is attempted.