of no importance to him that half an ounce of silver at Canton would have
given him the command of more labour, and of a greater quantity of the
necessaries and conveniencies of life than an ounce can do at London. An
ounce at London will always give him the command of double the quantity of
all these, which half an ounce could have done there, and this is precisely
what he wants.

As it is the nominal or money price of goods, therefore, which finally
determines the prudence or imprudence of all purchases and sales, and
thereby regulates almost the whole business of common life in which price is
concerned, we cannot wonder that it should have been so much more attended
to than the real price.

In such a work as this, however, it may sometimes be of use to compare the
different real values of a particular commodity at different times and
places, or the different degrees of power over the labour of other people
which it may, upon different occasions, have given to those who possessed
it. We must in this case compare, not so much the different quantities of
silver for which it was commonly sold, as the different quantities or labour
which those different quantities of silver could have purchased. But the
current prices of labour, at distant times and places, can scarce ever be
known with any degree of exactness. Those of corn, though they have in few
places been regularly recorded, are in general better known, and have been
more frequently taken notice of by historians and other writers. We must
generally, therefore, content ourselves with them, not as being always
exactly in the same proportion as the current prices of labour, but as being
the nearest approximation which can commonly be had to that proportion. I
shall hereafter have occasion to make several comparisons of this kind.

In the progress of industry, commercial nations have found it convenient to