The Wealth of Nations by Part 4 Chapter 1 Page 37

and can give employment to no more. The channel of circulation necessarily draws to itself a sum sufficient to fill it, and never admits any more.

Something, however, is generally withdrawn from this channel in the case of foreign war. By the great number of people who are maintained abroad, fewer are maintained at home. Fewer goods are circulated there, and less money becomes necessary to circulate them. An extraordinary quantity of paper money, of some sort or other, such as exchequer notes, navy bills, and bank bills in England, is generally issued upon such occasions, and by supplying the place of circulating gold and silver, gives an opportunity of sending a greater quantity of it abroad. All this, however, could afford but a poor resource for maintaining a foreign war of great expense and several years duration.