If the course of the exchange is watched with anxiety, it should be with regard to the nominal and not the real variation. As a test of the state of the currency of the country its deviations are important, and cannot be too narrowly observed by those in whom the power resides of enlarging and contracting the currency. But the real variation might be safely left to itself, even if there were no intervention of bill-brokers by which equalization is secured. The variation can never pass the amount by which the cost of transmitting payments in metal exceeds that of making payment in bills. This cost can never be great while there is a set of persons, like bill-brokers, to buy bills where they are cheapest, and sell them where they are dearest; and thus, by arbitrating the exchanges of different countries, equalize the whole. As such equalization aids the security of property, commerce is largely indebted to the intervention of this class of dealers. If any means could be found by which the rise and fall of money could take place at once and equally all over the trading world, there would be an end to nominal variations of exchange, and commerce would be divested of one of its mysteries: but this can never be while production is more abundant in one place than another; and while the cost of the carriage of commodities increases with distance. Mrs. Snoek found it cheaper living at Winkel than at Amsterdam: that is, the great articles of consumption were produced at hand, and had no cost of carriage to bear; and the value of the precious metals was therefore higher at Winkel than in Amsterdam, so much higher as to induce the Amsterdam exporter who made purchases of her butter and cheese to pay her in that commodity which was cheap to him while it was dear to her,--money. In return for the produce of her farm, which was shipped from her neighbourhood, there was a flow of money from Amsterdam to Winkel; a flow which would continue till money, becoming more plentiful at Winkel, fell in value so as to make it better worth the while of both parties that Mrs. Snoek should be paid in commodities. If the respective commodities should balance each other in value, so as to show that there was the same proportion of money in both places, no money would be transmitted; but if money at length abounded at Winkel more than at Amsterdam, it would become worth Mrs. Snoek's while, in her turn, to buy the merchant's commodities with that which was cheap to her while it was dear to him. Such inequalities must exist in different parts of the same country, and, much more, in different countries; and, while they do exist, the coins of countries will change their relative value, and there will be nominal variations of the exchange, wholly independent of the total amount of sales between different countries.