countries lies, or which of them exports to the greatest value. National prejudice and animosity, prompted always by the private interest of particular traders, are the principles which generally direct our judgment upon all questions concerning it. There are two criterions, however, which have frequently been appealed to upon such occasions, the custom-house books and the course of exchange. The custom-house books, I think, it is now generally acknowledged, are a very uncertain criterion, on account of the inaccuracy of the valuation at which the greater part of goods are rated in them. The course of exchange is, perhaps, almost equally so.
When the exchange between two places, such as London and Paris, is at par, it is said to be a sign that the debts due from London to Paris are compensated by those due from Paris to London. On the contrary, when a premium is paid at London for a bill upon Paris, it is said to be a sign that the debts due from London to Paris are not compensated by those due from Paris to London, but that a balance in money must be sent out from the latter place; for the risk, trouble, and expense, of exporting which, the premium is both demanded and given. But the ordinary state of debt and credit between those two cities must necessarily be regulated, it is said, by the ordinary course of their dealings with one another. When neither of them imports from from other to a greater amount than it exports to that other, the debts and credits of each may compensate one another. But when one of them imports from the other to a greater value than it exports to that other, the former necessarily becomes indebted to the latter in a greater sum than the latter becomes indebted to it: the debts and credits of each do not compensate one another, and money must be sent out from that place of which the debts overbalance the credits. The ordinary course of exchange, therefore, being an indication of the ordinary state of debt and credit between two places, must likewise be an indication of the ordinary course of their exports and imports, as these necessarily regulate that state.