Abstractedly considered, that is, apart from circumstances not
 immediately flowing from the laws of the simple circulation of commodities,
 there is in an exchange nothing (if we except the replacing of one use-value
 by another) but a metamorphosis, a mere change in the form of the commodity.
 The same exchange-value, i.e., the same quantity of incorporated social
 labour, remains throughout in the hands of the owner of the commodity,
 first in the shape of his own commodity, then in the form of the money
 for which he exchanged it, and lastly, in the shape of the commodity he
 buys with that money. This change of form does not imply a change in the
 magnitude of the value. But the change, which the value of the commodity
 undergoes in this process, is limited to a change in its money-form. This
 form exists first as the price of the commodity offered for sale, then
 as an actual sum of money, which, however, 
 
 was already expressed in the
 price, and lastly, as the price of an equivalent commodity. This change
 of form no more implies, taken alone, a change in the quantity of value,
 than does the change of a £5 note into sovereigns, half sovereigns
 and shillings. So far therefore as the circulation of commodities effects
 a change in the form alone of their values, and is free from disturbing
 influences, it must be the exchange of equivalents. Little as Vulgar-Economy
 knows about the nature of value, yet whenever it wishes to consider the
 phenomena of circulation in their purity, it assumes that supply and demand
 are equal, which amounts to this, that their effect is nil. If therefore,
 as regards the use-values exchanged, both buyer and seller may possibly
 gain something, this is not the case as regards the exchange-values. Here
 we must rather say, “Where equality exists there can be no gain.” [5]
 It is true, commodities may be sold at prices deviating from their values,
 but these deviations are to be considered as infractions of the laws of
 the exchange of commodities [6], which in its normal
 state is an exchange of equivalents, consequently, no method for increasing
 value. [7]