By experience men finally learned that the metals were best fitted to serve as a medium of exchange. Metallic money in some form was used at a very remote time in the world's history. Recent excavations in Egypt, Greece, Babylon and elsewhere have brought to light coins that were in use among these ancient peoples. It appears that at first the baser metals, like iron, tin and bronze, were used. Ancient Greek and Latin writers mention lead as having been used as currency. In this country the Massachusetts settlers used lead bullets for change, at the rate of a farthing each. In the days of the Roman Emperors, series of tin coins were issued, and tin halfpence and farthings were used in England as late as 1691. Copper has been used as money in all ages. The early Hebrews used copper coins chiefly, and the Roman coins were made of copper until displaced by silver. Because of its low and fluctuating value, however, it is unfitted for money, except in coins of small denominations. Nickel is used at the present time as an alloy with other metals. Belgium, Germany and the United States use it in their coinage. One objection to it is the wide fluctuation in the price of the crude nickel. Platinum, one of the comparatively rare metals, found principally in the Ural Mountains, has been experimented with by Russia. It possesses great density and durability and it is slow to tarnish. A few years' experience with it, however, led the Russian government to abandon its use as money. Because of its relative scarcity the value of the metal is unstable; furthermore, the cost of making the coins is very high, owing to the extremely high point at which platinum melts.

1 Jevons: Money and the Mechanism of Exchange, p. 20.

Gradually, as the standard of life and the level of prices rose and a more valuable unit came to be needed, the cheaper and heavier metals were displaced by silver and gold, which are in use as money to-day in every civilized nation in the world. Gold does not admit of division into coins small enough for pocket change, so silver and some of the baser metals, like nickel and copper, are used in coins of small denominations. A consideration of the qualities which a good medium of exchange should possess will show why gold has been adopted as standard money practically all over the world.