sending their commodities to a distant country. When foreign trade is not reciprocal (that is, when one country only sends commodities and is paid by the other in money) the advantage is all on one side, and therefore it has no permanence or stability; for the country which reaps no real advantage naturally gets tired of a trade from which it derives no benefit, and after a while such a trade is certain to cease. But when two countries exchange with each other the commodities which each has some comparative facility for producing, each country is permanently benefited, and therefore such a trade will be lasting and stable in its character. It is a first condition of any kind of permanent trade that each party to it shall be really benefited by the transaction; otherwise the one who is not benefited will withdraw from the trade, which would consequently come to an end. We have seen, then, that foreign trade, although the amount of it may be measured in money, must in reality be an exchange of commodities for commodities. But we have scarcely yet inquired "what commodities?" It will perhaps
