When the division of labour has been once thoroughly
established, it is but a very small part of a man’s wants
which the produce of his own labour can supply. He
supplies the far greater part of them by exchanging that surplus
part of the produce of his own labour, which is over and above his
own consumption, for such parts of the produce of other men’s
labour as he has occasion for. Every man thus lives by exchanging,
or becomes in some measure a merchant, and the society itself
grows to be what is properly a commercial society.
But when the division of labour first began to take place, this
power of exchanging must frequently have been very much
clogged and embarrassed in its operations. One man, we shall
suppose, has more of a certain commodity than he himself has
occasion for, while another has less. The former consequently
would be glad to dispose of, and the latter to purchase, a part of
this superfluity. But if this latter should chance to have nothing
that the former stands in need of, no exchange can be made
between them. The butcher has more meat in his shop than he
himself can consume, and the brewer and the baker would each of
them be willing to purchase a part of it. But they have nothing to
offer in exchange, except the different productions of their
respective trades, and the butcher is already provided with all the
bread and beer which he has immediate occasion for. No
exchange can, in this case, be made between them.he
can not be their merchant, nor they his customers; and they are all of them
thus mutually less serviceable to one another. In order to avoid the
inconveniency of such situations, every prudent man in every
period of society, after the first establishment of the division of
labour, must naturally have endeavoured to manage his affairs in
such a manner as to have at all times by him, besides the peculiar
produce of his own industry, a certain quantity of some one
commodity or other, such as he imagined few people would be
likely to refuse in exchange for the produce of their industry.
Many different commodities, it is probable, were successively
both thought of and employed for this purpose. In the rude ages of
society, cattle are said to have been the common instrument of
commerce; and, though they must have been a most inconvenient
one, yet in old times we find things were frequently valued
according to the number of cattle which had been given in
exchange for them. The armour of Diomede, says Homer, cost only
nine oxen; but that of Glaucus cost an hundred oxen. Salt is said to
be the common instrument of commerce and exchanges in
Abyssinia; a species of shells in some parts of the coast of India;
dried cod at Newfoundland; tobacco in Virginia; sugar in some of
our West India colonies; hides or dressed leather in some other
countries; and there is at this day a village in Scotland where it is
not uncommon, I am told, for a workman to carry nails instead of
money to the baker’s shop or the alehouse.