difficulty arose when
out of a pair of possible traders one had something which the other
wanted but the other had not. For example, if the arrow-maker had arrows
to sell and wanted to buy fish, there obviously could be no bargain if
his friend who wanted to buy arrows had only got deerskins to give in
exchange. It was essential to the development of trade that some
commodity should be hit on which could always be taken in exchange and
so form a circulating medium. We have seen from the twenty-third chapter
of Genesis that a certain weight of silver had in Abraham's time begun
to assume this function. Economic text-books tell us that many other
commodities had the form and function of money before the metals came
into use. Until quite lately there were many places in which the use of
an agreed medium of exchange had not been adopted to facilitate the
purposes of commerce. Jevons begins his very interesting book on money
by relating how

Some years since, Mdlle Zelie, a singer of the Theatre Lyrique at
Paris, made a professional tour round the world, and gave a
concert in the Society Islands. In exchange for an air from
_Norma_ and a few other songs, she was to receive a third of the
receipts. When counted, her share was found to consist of three
pigs, twenty-three turkeys, forty-four chickens, five thousand
cocoa-nuts, besides considerable quantities of bananas, lemons,
and oranges. At the Halles in Paris, as the prima donna remarks
in her lively letter, ... this amount of live stock and
vegetables might have brought four thousand francs [L160], which
would have been good remuneration for five songs. In the Society
Islands, however, pieces of money were very scarce; and as
Mademoiselle could not consume any considerable portion of the
receipts herself, it became necessary in the meantime to feed the
pigs and poultry with the fruit,'[27] and so her receipts
consumed one another.

This is an example of the inconvenience which the invention of money
overcame. In primitive communities it took the form of cowry-shells or
tobacco or gunpowder or any commodity which was in universal request in
the place. All the seller wanted to do was to be able to obtain for his
product a certain amount of stuff which he could rely on being able to
exchange for other things that he wanted. In the end the precious
metals, with their strong appeal to human vanity