The Wealth of Nations by Part 2 Chapter 2 Page 49

etc.; the expenses peculiar to a bank consist chiefly in two articles: first, in the expense of keeping at all times in its coffers, for answering the occasional demands of the holders of its notes, a large sum of money, of which it loses the interest; and, secondly, in the expense of replenishing those coffers as fast as they are emptied by answering such occasional demands.

A banking company, which issues more paper than can be employed in the circulation of the country, and of which the excess is continually returning upon them for payment, ought to increase the quantity of gold and silver, which they keep at all times in their coffers, not only in proportion to this excessive increase of their circulation, but in a much greater proportion; their notes returning upon them much faster than in proportion to the excess of their quantity.