154 APPEECIATION OF GOLD. course, the same thing as a general fall in prices, the very meaning of the expression is that a given amount of gold purchases more commodities than before. But general prices depend on a variety of causes, some operating in the same direction, and others antagonistic. There is no proposition better established in Politicai Economy than that, under certain conditions, the value of money (by which is meant not the rate of interest, but a high or low level of prices of things in general) varies inversely as its quantity multiplied by the rapidity of circula- tion. But the conditions laid down are, for practical purposes, of the highest moment. The two elements in the lawâthe quantity of money and the rapidity of circulationâmay be taken separately. It is easy to see, under the assumptions to be indicated, that the more money there is the less will be the ex- change value of every piece. The necessary assump- tions areâ(1) that the quantity of commodities to be exchanged, and the number of exchanges to be eifected, remain the same; (2) that money is used only for purposes of currency ;âthat is, that no account is taken of the other uses to which the material of which it is made can be applied ; (3) that money passes from band to band at every trans- actionâcredit, and even barter, being non-existent. Under these conditions it is obvious that the value of money must vary inversely as its quantity; if the quantity is doubled, general prices will be