The institution of a bank has also a natural relation to the regulation of trade between the States, in so far as it is conducive to the creation of a convenient medium of exchange between them, and to the keeping up a full circulation, by preventing the frequent displacement of the metals in reciprocal remittances Money is the very hinge on which commerce turns. And this does not merely mean gold and silver; many other things have served the purpose, with different degrees of utility. Paper has been extensively employed.