Commercial paper only is really liquid, since it represents a current commercial process which will soon be completed and the completion of which automatically provides the means for its payment. Such paper usually matures in short periods, but the characteristic of liquidity results not from the date at which it is made to mature, but from the commercial process which called it into existence and will ultimately retire it. In this country very often paper of short maturity is so in form only, its makers expecting to renew it, instead of pay it, at maturity. Bonds and stocks, even though they may be listed on a stock exchange and daily bought and sold, are not liquid securities in the proper sense of that term. An individual bank may be able to sell them in case of need, but such sale is simply the transfer of the investment to another bank or person, and not its liquidation. The security still exists and must be paid, while its liquidation would take it out of existence. Foreign legislators have approximated more closely than ours what is needed in the regulation of bank investments. In the case of their central banks, many of them, notably those of France and Germany, have recognized the fundamental distinction between commercial and investment paper, and have required them to hold the former against their demand obligations, especially their notes. The regulation of reserves has become a subject of legislation in this country only. Our national banking act classifies national banks into three groups, called country, reserve city, and central reserve city banks, and requires those in the first mentioned group to keep cash in their vaults to the amount of at least six per cent of their deposits, and balances in approved reserve city banks sufficient to bring the total amount up to fifteen per cent of their deposits. Banks in reserve cities are required to keep in their vaults cash to the amount of at least twelve and one-half per cent of their deposits, and balances in central reserve cities sufficient to bring the total up to twenty-five per cent of their deposits. Banks in central reserve cities are required to keep at least twenty-five per cent of their deposits in cash in their vaults. When the reserves of a bank fall to the prescribed minimum, all discounting must cease. Regulations essentially similar are found in the banking laws of most of our states.