MODERN MONETARY SYSTEMS (b) System of Paper Money. A system of paper money is usually the result of excep- tional circumstances in which notes are no longer con- vertible and are granted forced currency. In theory, gold and silver coins continue to be exchanged internally for notes according to the previous exchange rate correspond- ing to the number of units of account inscribed upon each monetary instrument. At the present time in France a ten franc note ought to be exchangeable for two five and two ten franc notes for one twenty franc piece ; no other pro- ceeding is known to the law. But in such circumstances gold coin soon disappears in practice through being exported or hoarded; and silver may likewise disappear unless it continues to perform the function of subsidiary coin. A régime of paper currency is usually preceded, accom- panied or followed by abnormal issues, but its essential characteristic is not necessarily either inflation or the disappearance of coin from internal circulation, but that the currency only circulates internally. Hitherto a given paper currency has almost always been peculiar to a single country ; hence this system does not provide a monetary basis in common with other national monetary systems. Almost all monetary phenomena which require elucida- tion and almost all the problems which need solution in countries on a paper currency will be seen to derive from this essential characteristic. The only requirement for bringing a system of paper currency back to the gold exchange standard is that paper should again become convertible into gold at a fixed rate for the purpose of payments abroad, although coin may have ceased to circulate internally and the note issue may not have been reduced to the previous figure. § 2. Monetary systems in operation; rudimentary notions of the mechanism of exchange. With the above definitions in mind it is easy to under- stand how monetary systems work generally and to grasp Q