at present struck. In actual practice, the standard is shown in
the ten-dollar piece, or eagle, weighing 258 grains. The half eagle (five
dollars) and the quarter eagle (two dollars and fifty cents) indicate upon
their face their relation to the principal coin. The double eagle, or
twenty-dollar piece, is coined for greater convenience. These coins
connect all the currency of the country directly with the market value of
commodities in the world, through gaining their value directly from the
market value of gold, where gold is bought and sold. Thus gold furnishes
the standard of value with which all other values are compared.

Silver coins of the United States are made from silver purchased by the
government. The dollar, adopted from the Spanish rix-dollar, itself
derived from the German thaler, is by law a coin of 412-1/2 grains of silver
nine-tenths fine. This silver dollar has a story of its own, which will be
given later, and does not form a part of the system of 1873. The half
dollar, the quarter dollar, and the dime, for fractional currency, are
proportional parts of 385.8 grains of silver nine-tenths fine. These are
about five per cent less in weight than the proportional parts of the
silver dollar. The original purpose of this reduced weight was to prevent
the consumption of these coins in ordinary uses by making them worth on
the face a little more than their bullion value. These fractional coins
are legal tender in the courts to the amount of five dollars. In nickel
and copper coins no effort has been made for many years to maintain a
standard of value, the amount of metal in any of them being far less in
value than their face. They are legal tender only to the amount of
twenty-five cents.

_Fluctuation of standards._--In the study of the precious metals as the
standard of prices, it is necessary to remember that the value of these
metals, like that of all products of labor, is subject to considerable
fluctuations. The very fact that gold and silver are durable metals, not
easily consumed or readily worn away, tends to make the increased product
in a series of years less and less valuable. While the ordinary increase
in product may be provided for by increased demand through extended
exchange, the very improvements in the machinery of exchange, especially
the extension of general credit, operate in the opposite direction.

It is certain that the value of gold and silver within one hundred years
after the dis