It would be too ridiculous to go about seriously to prove that wealth does not consist in money, or in gold and silver; but in what money purchases, and is valuable only for purchasing. Money no doubt, makes always a part of the national capital; but it has already been shown that it generally makes but a small part, and always the most unprofitable part of it.

Chapter I, p. 470. - The Wealth of Nations (1776) - Book IV