Page:The wealth of nations, volume 1.djvu/432

 the interest. The coffers of the bank, so far as its dealings are confined to such customers, resemble a water pond, from which, though a stream is continually running out, yet another is continually running in, fully equal to that which runs out; so that, without any further care or attention, the pond keeps always equally, or very near equally full. Little or no expense can ever be necessary for replenishing the coffers of such a bank.

A merchant, without overtrading, may frequently have occasion for a sum of ready money, even when he has no bills to discount. When a bank, besides discounting his bills, advances him likewise upon such occasions, such sums upon his cash account, and accepts of a piecemeal repayment as the money comes in from the occasional sale of his goods, upon the easy terms of the banking companies of Scotland; it dispenses him entirely from the necessity of keeping any part of his stock by him unemployed and in ready money for answering occasional demands. When such demands actually come upon him, he can answer them sufficiently from his cash account. The bank, however, in dealing with such customers, ought to observe with great attention, whether in the course of some short period (of four, five, six, or eight months, for example) the sum of the repayments which it commonly receives from them, is, or is not, fully equal to that of the advances which it commonly makes to them. If, within the course of such short periods, the sum of the repayments from certain customers is, upon most occasions, fully equal to that of the advances, it may safely continue to deal with such customers. Though the stream which is in this case continually running out from its coffers may be very large, that which is continually running into them must be at