The extent of the home trade, and of the capital which can be employed in it, is necessarily limited by the value of the surplus produce of all those distant places within the country which have occasion to exchange their respective productions with one another; that of the foreign trade of consumption, by the value of the surplus produce of the whole country, and of what can be purchased with it; that of the carrying trade, by the value of the surplus produce of all the different countries in the world.