The Wealth of Nations by Part 2 Chapter 2 Page 119

Though paper money should be pretty much confined to the circulation between dealers and dealers, yet banks and bankers might still be able to give nearly the same assistance to the industry and commerce of the country as they had done when paper money filled almost the whole circulation. The ready money which a dealer is obliged to keep by him, for answering occasional demands, is destined altogether for the circulation between himself and other dealers of whom he buys goods. He has no occasion to keep any by him for the circulation between himself and the consumers, who are his customers, and who bring ready money to him, instead of taking any from him. Though no paper money, therefore, was allowed to be issued but for such sums as would confine it pretty much to the circulation between dealers and dealers, yet, partly by discounting real bills of