art of a country's capital._--The coined money of a country thus
becomes wealth in store for constant use as a machine of exchange. Its
operation is effective when it keeps in constant motion, being itself
consumed very slowly in the wear and tear of motion. It is sometimes
compared to an endless screw, transmitting motion to everything else with
which it comes in contact. Like other machines, it may be either too
abundant or too scarce for the best advantage of the country. In either
case there is waste. When the coin is idle it is unproductive, but suffers
less waste from deterioration than almost any other kind of machine. In
case of scarcity the cost of its use is increased under the general law of
supply and demand, exactly as the cost of other machinery in use is
advanced when many desire to use it. This machine is a prominent part of
the capital of a country, greater in some countries than in others. In
France the value of coin is estimated to be 3 per cent of the value of all
real estate, including buildings. The use of such a machine makes a
material part of the annual cost of exchanges. The coin of England, where
interest is comparatively low, costs for its use in interest, wear and
tear, and re-coinage more than $20,000,000 annually.

An additional cost to individuals is in the extra risk of carrying such
wealth, as shown in express charges and special insurance, and still
greater expense for safe keeping, and a considerable use of time in
counting. These facts have led to many devices for lessening the need of
keeping wealth in this form.

_Credit by accounts._--The most obvious method of avoiding the use of coin
in exchanges is a current account between individuals having many
transactions in trade. A farmer carries his butter, eggs, fruits, grains
and live stock, perhaps, to a single dealer in all these articles, and
takes in return articles of household use or for any necessity as he
requires them, from a spool of thread to a harvester. If both keep
accurate accounts, a settlement once in six months satisfies most
conveniently all the requirements of perfect trade. Indeed the settlement
is needed only that the accounts may be verified. Except for the dangers
of waste in unlimited credit and carelessness in expenditure where future
wealth is drawn upon, this method of exchange is simple and inexpensive.
In the nature of the case, however, it must be limited, for safety, to
trade between people having confi