The Wealth of Nations by Part 4 Chapter 1 Page 13

That high price, indeed, was extremely disadvantageous to the merchants who had any money to pay in foreign countries. They paid so much dearer for the bills which their bankers granted them upon those countries. But though the risk arising from the prohibition might occasion some extraordinary expense to the bankers, it would not necessarily carry any more money out of the country. This expense would generally be all laid out in the country, in smuggling the money out of it, and could seldom occasion the exportation of a single sixpence beyond the precise sum drawn for. The high price of exchange too would naturally dispose the merchants to endeavour to make their exports nearly balance their imports, in order that they might have this high exchange to pay upon as small a sum as possible. The high price of exchange, besides, must necessarily have operated