Labour, it must always be remembered, and not any particular commodity, or set of commodities, is the real measure of the value both of silver and of all other commodities.
But in countries almost waste, or but thinly inhabited, cattle, poultry, game of all kinds, etc. as they are the spontaneous productions of Nature, so she frequently produces them in much greater quantities than the consumption of the inhabitants requires. In such a state of things, the supply commonly exceeds the demand. In different states of society, in different states of improvement, therefore, such commodities will represent, or be equivalent, to very different quantities of labour.
In every state of society, in every stage of improvement, corn is the production of human industry. But the average produce of every sort of industry is always suited, more or less exactly, to the average consumption; the average supply to the average demand. In every different stage of improvement, besides, the raising of equal quantities of corn in the same soil and climate, will, at an average, require nearly equal quantities of labour; or, what comes to the same thing, the price of nearly equal quantities; the continual increase of the productive powers of labour, in an improved state of cultivation, being more or less counterbalanced by the continual increasing price of cattle, the principal instruments of agriculture. Upon all these accounts, therefore, we may rest assured, that equal quantities of corn will, in every state of society, in every stage of improvement, more nearly represent, or be equivalent to, equal quantities of labour, than equal quantities of any other part of the rude produce of land. Corn, accordingly, it has already been observed, is, in all the different stages of wealth and improvement, a more accurate measure of value than any other commodity or set of commodities. In all those different stages, therefore, we can judge better of the real value of silver, by comparing it with corn, than by comparing it with any other commodity or set of commodities.