That silver came under men’s notice at a later time than either gold or copper can be put beyond doubt by historical evidence. In the Rig Veda, where gold (_heranya_) is already well known and likewise copper (for there can be no doubt that the _ayas_ of the Veda, Lat. _aes_, means copper), silver is entirely unknown; the word _rayatam_, which in later Sanskrit means silver, does indeed occur, but only as an adjective applied to a horse and meaning _bright_. Again, we know as a matter of fact that it was only at a comparatively late period that the famous silver mines of Laurium in Attica were developed. At least Plutarch (_Solon_, ch. 16) tells us that, owing to the scarcity of silver coin, Solon reduced the amount of the fines levied and also of the rewards for killing a wolf or wolf-cub, the former to five drachms, the latter to one drachm, the rewards representing the value of a cow and a sheep respectively. If they had already learned to work that “well of silver, the treasure-house of their land,” in the time of Solon (596 B.C.), there certainly could have been no such dearth of silver. Finally let us take a comparatively modern case, that of the Aztecs of Mexico. When the Spanish conquerors reckoned up their great tale of treasures found in the royal palace, whilst the gold amounted to the large sum of _pesos de oro_ 162000 lbs., the silver and silver vessels only weighed the small sum of 500 marks[90]. Yet this was in the country that is now known as the richest silver-producing region that the world has ever seen. We thus find a people in a highly advanced state of civilization, who had invented a calendar, had devised a system of picture-writing, who had actually a currency in gold-dust, as we have found, and who were skilled and artistic craftsmen in gold, and yet who were scarcely able to make the slightest use of the silver, with which almost every crevice in their native hills was charged. We may thus with safety rest in the conclusion that silver only comes into use at a stage always and probably much later than gold.