Let us now consider the effects of circulation in the purchase of land. (A), I shall suppose, has a piece of land, and (B) has one thousand pounds weight of gold coin, which the laws of society have constituted to be an adequate circulating equivalent for every thing vendible. They agree to make an exchange. Before the exchange the balance of their wealth is equal; the coin is worth the land, the land is worth the coin; the exchange makes no alteration, nor has it the effect of making any afterwards; the new landlord may apply himself to the improvement of the soil, the monied man to the turning of his thousand weight of gold coin to the best advantage; consequently, by this transaction, no vibration of the balance seems to be affected. If coin itself be the object of sale, the consequences are much the same. (A) has a guinea, (B) has twenty one shillings, the exchange they make produces no alteration in their circumstances. The same holds good in other species of circulation, such as the transmission of money by inheritance. (A) dies and leaves his money to (B); here the possessor of the money only changes his name, perhaps his inclinations, and that is all. In like manner a person pays his debts, and withdraws his bond, or other security; no balance is affected by this circulation, matters stand between the parties just as before. The nature, therefore, of circulation, when one inconsumable commodity is given for another, is, that it operates no vibration in the balance of wealth between the parties; because, in order to produce this, one must remain richer than he was before, and the other proportionally poorer. II. Under the second head of alienation, to wit, that of consumable commodities, is comprehended every thing corporeal, except money, and land, which money may purchase. In these, two things deserve attention. First, the simple substance, or the production of nature; the other, the modification, or the work of man. The first I shall call the _intrinsic worth_, the other, the _useful value_. The value of the first, must always be estimated according to its usefulness after the modification it has received is entirely destroyed, and when by the nature of the thing both must be consumed together, then the total value is the sum of both. The value of the second must be estimated according to the labour it has cost to produce it. An example will make this plain.