In the above series of equations iron, wheat, coffee, potash, etc. appear to each other as embodiments, of homogeneous labor, namely, as labor materialized in money, from which all the peculiarities of the different kinds of concrete labor represented in the different use-values are completely eliminated. As value they are all identical, they are the incarnation of _the same_ labor, or _the same_ incarnation of labor, viz., gold. As uniform embodiments of the same labor they display only _one_ difference, a quantitative one, by appearing as different quantities of value, because _unequal_ quantities of labor-time are contained in their use-values. The mutual relation of these separate commodities is that of embodiments of universal labor-time, since they are related to universal labor-time as to an excluded commodity, viz., gold. The same relation the development of which causes commodities to appear to each other as exchange values, causes the labor time contained in gold to appear as universal labor-time, a given quantity of which is expressed in different quantities of iron, wheat, coffee, etc,―in short, in the use-values of all 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.