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 of others, and that what has just been said of labour may be said of cloth, cotton, iron, hops, or any other article. Any two commodities, which at the same time and in the same place will purchase or command the same quantity of cloth, cotton, iron, or hops of a given quality, will have the same value, or will exchange even with each other. This is no doubt true, if we take the same time precisely, and if we wish merely to know the relation of one commodity to some other or others in exchange; but the comparison utterly fails if we take different periods, and more especially if we refer to the main characteristic of the value of a commodity, namely, the difficulty of obtaining it, or the limitation of its supply compared with the demand.

One of the most important reasons why practically money makes a much better measure of value than any other commodity is, that its relation to common labour not only changes more slowly than cloth, cotton, iron, hops, &c. but that having been adopted as the almost universal medium of exchange, its relation to labour in any particular place must always be known to the inhabitants of that place; and while such relation is known and remains constant, the money prices of commodities will not only express their relations to each other, but also the difficulty of obtaining them, the conditions of their continued supply, if they are in an ordinary state, and the supply compared with the demand in whatever state they may be, which will include of course their power of purchasing arising from all the intrinsic causes of value which may have operated upon them.

Consequently money, under these circumstances, that is, while its relation to labour is known and remains constant, is a measure both of relative and intrinsic value in exchange.

But if the only cause which prevents money from being such a measure is, that its relation to labour is not constant, it would appear, that as the labour which a commodity will command is necessarily a measure