commodities, or is directly unfolded in the endless series of commodity-equivalents. While all commodities express their exchange values in gold, gold expresses its exchange value directly in all commodities. While commodities assume the form of exchange value in relation to each other, they lend to gold the form of the universal equivalent, or of money.
Gold becomes the measure of value, because all commodities measure their exchange values in gold, in proportion as a certain quantity of gold and a certain quantity of the commodity contain the same amount of labor-time; and it is only by virtue of this function of being a measure of value, in which capacity its own value is measured directly in the entire series of commodity equivalents, that gold becomes a universal equivalent or money. On the other hand, the exchange value of all commodities is expressed in gold. In this expression, the qualitative aspect is to be distinguished from the quantitative: there is the exchange value of the commodity as the embodiment of the same uniform labor-time; while the magnitude of value is exhaustively expressed, since in the same proportion in which commodities are equated to gold they are equated to one another. On the one hand the universal character of the labor-time contained in them is revealed; on the other, its quantity is expressed in its golden equivalent. The exchange value of commodities thus expressed in the form of a universal equivalent and, moreover, as a numerical proportion of this equivalent, in terms of one specific commodity, or represented in the form of a series of commodities equated to one specific commodity, is PRICE. Price is the form into which the exchange value of commodities is converted when it appears within the sphere of circulation.
By the same process by which commodities express their values in gold prices, they turn gold into a measure of value i. e. into money. If all of them were to measure their values in silver, wheat, or copper, and therefore express them in the form of silver, wheat or copper prices,