The Wealth of Nations by Part 4 Chapter 1 Page 10

merchant who purchased a bill upon the foreign country being obliged to pay the banker who sold it, not only for the natural risk, trouble, and expense of sending the money thither, but for the extraordinary risk arising from the prohibition.

But that the more the exchange was against any country, the more the balance of trade became necessarily against it; the money of that country becoming necessarily of so much less value in comparison with that of the country to which the balance was due. That if the exchange between England and Holland, for example, was five per cent against England, it would require a hundred and five ounces of silver in England to purchase a bill for a hundred ounces of silver in Holland: that a hundred and five ounces of silver in England, therefore, would be worth only a hundred ounces of silver