36. For want of an exact correspondence between the value and
the number or quantity, it is supplied by a mean valuation, which
becomes a species of real money.
In a country where there are only one race of sheep, we may
easily take the value of a fleece or of a sheep by the common
method of valuation, and we may say that a barrel of wine, or a
piece of stuff, is worth a certain number of fleeces or of sheep.
There is in reality some inequality in sheep, but when we want to
sell them, we take care to estimate that inequality, and to
reckon (for example) two lambs for one sheep. When it is
necessary to treat of the relative value of other merchandize, we
fix the common value of a sheep of middling age and quality, as
the symbol of unity. In this view the enunciation of the value of
sheep, becomes an agreed language, and this word one sheep, in
the language of commerce, signifies only a certain value, which,
in the mind of him who understands it, carries the idea not only
of a sheep, but as a certain quantity of every other commodity,
which is esteemed equivalent thereto, and this expression is more
applicable to a fictitious and abstract value, than to the value
of a real sheep; that if by chance a mortality happens among the
sheep, and that to purchase one of them, you must give double the
quantity of corn or wine that was formerly given, we shall rather
say, that one sheep is worth two sheep, than change the
expression we have been accustomed to for all other valuations.
