The results of the process of investment in commercial paper and in other securities are best understood when we trace the effect in the account of the bank. Taking then the account as it stood after the purchase of fixtures, let us suppose that the bank buys paper or securities from those dealing with it, or, in the common phrase, makes "loans to its customers," to the amount of $90,000, the paper being in many pieces and having various lengths of time to run, but averaging about three months. Supposing the interest to be computed at 6 per cent., we should have the account changed by the operation as follows:

LiabilitiesResources
Capital$100,000Loans$90,000
Undivided profits1,350Real estate, furniture, fixtures, etc.5,000
Deposit88,650Specie95,000
———— ————
$190,000$190,000

Here we have the securities which certify the right of the bank to demand and receive $90,000 at a future date placed among the resources; the net proceeds of the securities, or the aggregate of the sums which the bank holds itself liable to pay for them on demand, stand among the liabilities as deposits; and the interest deducted in advance, or the profit on the operation, which the bank must at the proper time account for to the stockholders, also stands as a liability. This, however, is the condition of the account at the moment of making the investment, when the bank has made its purchase of securities by merely creating a liability. As this liability is real and must be met, so far as the depositors at any time see fit to press it, let us suppose that depositors call for cash to the amount of $15,000, and we shall have a further change in the account as follows:

Liabilities
Capital$100,000
Undivided profits1,350
Deposits73,650
———
$175,000
Resources
Loans$90,000
Real estate, etc5,000
Specie80,000
———
$175,000

It is clear that, unless the enforcement of the liability for deposits and consequent withdrawal of specie goes much farther than this, the bank can safely increase its loans or its purchase of securities, although its method of doing so is by the increase of its liabilities. We will suppose it, therefore, to have expanded its affairs until it has reached something like the average condition of those banks in the United States, which, being incorporated under the laws of the several States, are not authorized to issue notes. It will then stand thus:

Liabilities
Capital$100,000
Surplus29,000
Undivided profits10,000
Deposits305,000
————
$444,000
Resources
Loans$305,000
Bonds and stocks23,000
Real estate15,000
Other assets20,000
Expenses1,000
Legal-tender notes}
Cash items} 80,000
Specie}
————
$444,000

Postponing for the present the consideration of some terms which here occur for the first time, it appears from the above account that purchases of securities have been made to more than three times the amount of the capital, and that this has been effected chiefly by the creation of liabilities in the form of deposits. What determines the limit to which this process can be carried?

If depositors seldom demanded the payment to which they are entitled, but were contented with the mere transfer of their rights among themselves as a conventional currency, the bank might dispense with holding any large amount of specie or cash in any form and keep most of its resources employed in its productive securities. The expansion of the deposits would then resemble in its effects the expansion of any other currency and might go on until a check should be interposed by the consequent rise of prices and demand for specie for exportation. And it is true, as we shall see, that in communities where banking is largely practised, the use of deposits as currency by transfer from hand to hand is so extensive, that a bank in good credit can rely upon their being withdrawn so slowly, or rather to so small an extent, as to make it unnecessary to have cash in readiness for the payment of more than a small proportion at any given moment. But in a period of financial disorder or alarm, withdrawals may be made earlier or more frequently, and a larger provision of cash may be needed for safety, than at other times; the kind of business carried on by depositors may expose one bank, or the banks in one place, to heavier occasional demands, or may on the other hand make demands steadier, than is the case elsewhere; and a city bank may be more subject to heavy calls from depositors than a country bank. In general, then, for every bank, in its place and under the circumstances of the time, there is some line below which its provision of cash cannot safely fall. This provision of cash, which in the account last given includes the cash items, specie, and legal-tender notes, is called the reserve, and the necessity of maintaining a certain minimum reserve fixes a limit to the ability of the bank to increase its securities. For obviously any increase of securities, that is, of loans or bonds, must ordinarily be effected, either by an increase of deposits, or by an actual expenditure of cash. If, then, the reserve were already as low as prudence would allow, or were threatened by approaching heavy demands from depositors, no increase of securities could be made without serious risk.