The desires of the rich, and the means of gratifying them, make them call for the services of the poor: the necessities of the poor, and their desire of becoming rich, make them chearfully answer the summons; they submit to the hardest labour, and comply with the inclinations of the wealthy, for the sake of an equivalent in money. This permutation between the two classes, is what we call circulation; and the effects produced by it, upon the political situation of the parties at the precise time of the circulation, and the consequences after it is compleatly effected, explains what is called the balance of wealth. To render our ideas more correct, let us consider the money on one side, and the prestations, as the civilians call them, or performances of any kind, on the other, as _reciprocal_ equivalents for one another; and then let us examine the nature of those prestations which tend to put these equivalents into circulation; that is to say, what are the things which money can purchase. These we may divide, with the lawyers, into corporeal and incorporeal. The corporeal may again be divided into consumable and inconsumable; and the incorporeal into personal service, and what the lawyers call _jura_, rights in or to any thing whatever. I cannot fully explain myself without the help of this distribution. Let us next consider the effects of the circulation of money, as it has for its object, the acquisition of the four several species here laid down. 1. Of inconsumable things. 2. Of things consumable. 3. Of personal service. 4. Of rights acquired in or to any thing whatever. I. The only thing inconsumable is the surface of the earth. This must not be taken in a philosophical, and far less in a chemical sense. A thing is consumed, so far as it concerns our inquiry, the moment it becomes useless, or even when it is lost. The surface of the earth, therefore, is the only thing inconsumable; because, generally speaking, it never can cease to be useful, and never can be lost; it may be changed, but the earth must always have a surface. What is said of the surface, may be understood likewise of that small part of its body accessible to man, for supplying him with what he finds useful there, as the produce of mines. Next to the earth itself, nothing is less consumable than her metals, consequently coin may very properly be classed under the head of things inconsumable; although it may be lost, and even worn out in circulation.