measured by any one of them. Each commodity would also be a representative of value. The possessor of a quart of wine might consider himself in possession of a value equal to four pounds of bread, a pound of cheese, a certain portion of leather, &c. &c. and thus each commodity would, with more or less accuracy and convenience, possess two essential properties of money, that of being both a representative and a measure of value.
But long before it is conceivable that this general valuation of commodities, with regard to each other should have taken place to any considerable extent, or with any tolerable degree of accuracy, a great difficulty in making exchanges, and in the determination of relative value would be constantly recurring from the want of a reciprocal demand. The possessor of venison might want bread, but the possessor of bread to whom he applied might not want venison, or not that quantity of it which the owner would wish to part with. This want of reciprocal demand would occasion in many instances, and in places not very remote from each other, the most unequal exchanges, and except in large fairs or markets where a great quantity and variety of commodities were brought together, would seem almost to preclude the possibility of any thing like such a general average valuation as has been just described. Every man, therefore, in order to secure this reciprocal demand, would endeavour, as is justly stated by Adam Smith, so to carry on his business, as to have by him, besides the produce of his own particular trade, some commodity for which there was so general and constant a demand, that it would scarcely ever be refused in exchange for what he wanted. In order that each individual in a society should be furnished with that share of the whole produce, to which he is entitled, by his wants and powers, it is not only necessary that there should be some measure of this share, but some medium by which he can obtain it in the quantity and at the time best suited to him.
The constantly recurring want of some such medium
