ABSTRACT
Money is the measure and standard of value and the medium of exchange, yet it is not necessary that should enter upon more than a very brief discussion concerning the nature of value, and the advantage of exchange. Every act of exchange thus presents itself to us in the form of a ratio between two numbers. The word value is commonly used, and if, at current rates, one ton of copper exchanges for ten tons of bar iron, it is usual to say that the value of copper is ten times that of the iron, weight for weight. It is only, then, when supplied in moderate quantities, and at the right time, that a thing can be said to be useful. Utility is not a quality intrinsic in a substance, for, if it were, additional quantities of the same substance would always be desired.
