The banker, to the extent of his own private capital, (the expenses of his business being first paid,) is a lender at interest. But, being subject to risk and trouble fully equal to that which belongs to most other employments, he cannot be satisfied with the mere interest even of his whole capital: he must have the ordinary profits of stock, or he will not engage in the business: the state of banking must be such as to hold out to him the prospect of adding, to the interest of what remains of his own capital after paying the expenses of his business, interest upon capital deposited with him, in sufficient amount to make up, after paying the expenses, the ordinary profit which could be derived from his own capital in any productive employment. This will be accomplished in one of two ways. 1. If the circumstances of society are such as to furnish a ready investment of disposable capital; (as for instance in London, where the public funds and other securities, of undoubted stability, and affording great advantages for receiving the interest without trouble and realizing the principal without difficulty when required, tempt all persons who have sums of importance lying idle, to invest them on their own account without the intervention of any middleman;) the deposits with bankers consist chiefly of small sums likely to be wanted in a very short period for current expenses, and the interest on which would seldom be worth the trouble of calculating it. Bankers, therefore, do not allow any interest on their deposits. After paying the expenses of their business, all the rest of the interest they receive is clear gain. But as the circumstances of banking, as of all other modes of employing capital, will on the average be such as to afford to a person entering into the business a prospect of realizing the ordinary, and no more than the ordinary, profits upon his own capital; the gains of each banker by the investment of his deposits, will not on the average exceed what is necessary to make up his gains on his own capital to the ordinary rate. It is, of course, competition, which brings about this limitation. Whether competition operates by lowering the rate of interest, or by dividing the business among a larger number, it is difficult to decide. Probably it operates in both ways; but it is by no means impossible that it may operate in the latter way alone: just as an increase in the number of physicians does not lower the fees, though it diminishes an average competitor's chance of obtaining them.