>>5163992
Different metals have been made use of by different nations
for this purpose. Iron was the common instrument of commerce
among the ancient Spartans; copper among the ancient Romans; and
gold and silver among all rich and commercial nations.
Those metals seem originally to have been made use of for
this purpose in rude bars, without any stamp or coinage. Thus we
are told by Pliny, upon the authority of Timaeus, an ancient
historian, that, till the time of Servius Tullius, the Romans had
no coined money, but made use of unstamped bars of copper, to
purchase whatever they had occasion for. These bars, therefore,
performed at this time the function of money.