But when we say that a man is worth fifty or a hundred pounds a year, we mean commonly to express not only the amount of the metal pieces which are annually paid to him, but the value of the goods which he can annually purchase or consume.

We mean commonly to ascertain what is or ought to be his way of living, or the quantity and quality of the necessaries and conveniencies of life in which he can with propriety indulge himself.

When, by any particular sum of money, we mean not only to express the amount of the metal pieces of which it is composed, but to include in its signification some obscure reference to the goods which can be had in exchange for them, the wealth or revenue which it in this case denotes, is equal only to one of the two values which are thus intimated somewhat