Fifthly, the determination of the metal reserve of the so-called national banks, a determination, however, which does not by itself regulate the magnitude of this metal hoard, for it can grow solely by the paralysis of domestic and foreign trade, is threefold: 1) reserve fund for international payments, in other words, reserve fund of world-money; 2) reserve fund for alternately expanding and contracting domestic metal circulation; 3) reserve fund for the payment of deposits and for the convertibility of notes (this is connected with the function of the bank and has nothing to do with the functions of money as such). The reserve fund can, therefore, also be influenced by conditions which affect every one of these three functions. Thus, as an international fund it can be influenced by the balance of payments, no matter by what factors the latter may be determined and whatever its relation to the balance of trade may be. As a reserve fund for domestic metal circulation it can be influenced by the latter's expansion or contraction. The third function — that of a security fund — does not, admittedly, determine the independent movement of the metal reserve, but has a two-fold effect. If notes are issued which replace metallic money (also including silver coins in countries where silver is a measure of value) in domestic circulation, the function of the reserve fund under 2) drops away. And a portion of the precious metal, which served to perform this function, will for a long time find its way abroad. In this case metallic coins are not withdrawn for domestic circulation, and thus the temporary augmentation of the metal reserve by immobilising a part of the circulating coined metal simultaneously falls away. Furthermore, if a minimum metal reserve must be maintained under all circumstances for the payment of deposits and for the convertibility of notes, this affects in its own way the results of a drain or return flow of gold; it affects that part of the reserve which the bank is obliged to maintain under all circumstances, or that part which it seeks to get rid of as useless at certain times. If the circulation were purely metallic and the banking system concentrated, the bank would likewise have to consider its metal reserve as security for the payment of its deposits, and a drain of metal could cause a panic such as was witnessed in Hamburg in 1857.