England, according to Jacob, was two to one, and in entire Europe and America the precious metals in the form of articles of luxury exceeded those in the form of money by one-fourth. We have seen that the circulation of money is but the manifestation of the metamorphoses of commodities, or of the form under which the social interchange of matter takes place. With the change in the total price of commodities in circulation or in the volume of their simultaneous metamorphoses, the rapidity of their change of form in each case being given, the total quantity of gold in circulation must always expand or contract. That is possible only under the condition that the total quantity of money in the country continually bear a varying ratio to the quantity of money in circulation. This condition is met by the process of hoarding. With a fall in prices or rise in the rapidity of circulation, the hoard-reservoirs absorb that part of money which is thrown out of circulation; with a rise in price or a decline in the rapidity of circulation, the hoards open up and return a part of their contents to the stream of circulation. The solidification of circulating money into hoards and the outpouring of hoards into circulation is a constantly oscillating movement in which the prevalence of the one or the other tendency is determined exclusively by fluctuations in the circulation of commodities. Hoards thus serve as conduits for the supply and withdrawal of money to or from circulation, so that every time only that quantity of money circulates as coin which is required by the immediate needs of circulation. If the volume of the entire circulation suddenly expands and the fluent unity of sale and purchase assumes such dimensions that the total sum of prices to be realized increases more rapidly than the rapidity of the circulation of money, the hoards decrease perceptibly; but when the combined movement slackens to an unusual extent, or the movement of buying and selling steadies itself, the medium of circulation solidifies into money in large measure, and the treasure reservoirs fill up far above their average level. In countries with an exclusively metallic circulation or where production is at a low stage of development, the hoards are endlessly split up and scattered all over the land, while in countries where the capitalist system is developed they are concentrated in bank reservoirs. Hoards are not to be confounded with coin reservoirs, which form a constituent part of the total supply of money in circulation, while the interaction between hoards and currency implies the decline or rise of its total supply. Gold and silver commodities form, as we have seen, both conduits for the withdrawal of precious metals, as well as sources of their supply. In ordinary times only their former function is of importance to the economy of metallic circulation.[102] b. MEANS OF PAYMENT.