We see by this that all the kinds of commodities that can be the object of Commerce measure one another, so to speak; that each may serve as a common measure or a scale of comparison to which to refer the values of all the others; and in like manner each commodity becomes in the hands of its possessor a means to procure all the others: a sort of universal pledge.
S35
Every commodity[1] does not present an equally convenient scale of values. The preference, therefore, has necessarily been given in practice to those which, not being susceptible of a great difference in quality, have a value principally relative to the number or the quantity.
But although all commodities have essentially this property of representing all others, of being able to serve as a common measure to express their value, and as a universal pledge to procure all of them by the means of exchange, all cannot be employed with the same facility for these two purposes. The more a commodity is susceptible to change of value in proportion[2] to its quality, the more difficult it is to make it serve as a scale to which to refer the value of other commodities. For example, if eighteen pints of the wine of Anjou are the equivalent of one sheep, eighteen pints of the wine of the Cape will be the equivalent of eighteen sheep. So that he who in order to express the value of a sheep, should say that it was worth eighteen pints of wine would employ language that was equivocal,
