If only the extraordinary commodity acting as money could be replaced in trade by an IOU, a sight draft, a representative claim on a given quantity of the same commodity! Society could retain the exchange services of money while economising on the capital – say, gold or silver coins – which is used up to embody the commodity medium of exchange.
Bills convertible into the commodity money would be circulating in lieu of – or at least in parallel to – gold or silver coins. Hence, a fraction of the stock of those precious metals could be unfrozen from circulation and diverted to other productive uses.