ance each other. Still later navigation reached to all the shores of the Old World, and finally into the Western hemisphere. With every addition to the field of human knowledge and enterprise there was a corresponding increase in the volume of exchanges and in the variety of manufactures and useful conveniences. Each country and district parted with that which it had in superabundance, or was particularly skilled in producing, for goods that were scarce or wanting to it, or that its own artificers were not accustomed to manufacture.
The same system of operations continues extending at the present day, and may do so apparently for an indefinite time. Every new country brought under cultivation, every new discovery of the treasures of the earth and waters, every new appliance adding to our powers and to our facilities of communication, and even every increase in itself in the sum of trading operations, forms the basis of new exchanges to mutual advantage; for the greater the quantities the smaller the profit at which it will pay to exchange them. Experience keeps constantly adding to our knowledge of the special advantages of each locality, and every free movement of trade and industry increases the sum of their usefulness to the human race. Scarcity of food can no longer exist among nations that have kept abreast of this economical revolution. The aggregate of comforts and luxuries generally attainable has multiplied enormously, and the mere operations of exchange give directly and indirectly steady and profitable employment to vast numbers. Nor is this freer exchange of commodities and of ideas attended, as many suppose, by increased competition between men and nations, for it is accompanied by a better and more wide-spread division of labor, and men by degrees cease to produce these articles in which they are manifestly at a disadvantage, and the disposal of which entails loss and disappointment. Those who doubt the advantages of this universal, world-wide intercourse and exchange are bound in consistency to advocate the reversion of society not merely to any earlier stage in its development, but to that state of things which preceded its initiation that is, to pure and simple cannibalism; for an argument that is good against one step in this march of progress is equally good against another. As it is certain, too, that this same movement, in spite of wars and governmental interferences, is constant and resistless, there can be no more important question than how best to conform to and profit by it, which we may learn by observing how men and nations naturally find their most suitable and profitable occupations.
The general principles determining the employment of the soil of different countries and localities are tolerably simple. Com-
