These dangers, threatening alike to the moral character and material welfare of nations, are completely prevented by the simple law, the operations of which we every day see around us--viz. that wealth, civilization, and knowledge, add rapidly and indefinitely to the powers of manufacturing and commercial, but comparatively slowly to those of agricultural industry. This simple circumstance effectually provides for the dispersion of the human race, and the check of an undue growth in particular communities. The old state can always undersell the young one in manufactures, but it is everlastingly undersold by them in agriculture. Thus the equalization of industry is introduced, the dispersion of the human race secured, and a limit put to the perilous multiplication of its members in particular communities. The old state can never rival the young ones around it in raising subsistence; the young ones can never rival the old one in manufactured articles. Either a free trade takes place between them, or restrictions are established. If the commercial intercourse between them is unrestricted, agriculture is destroyed, and with it national strength is undermined in the old state, and manufactures are nipped in the bud in the young ones. If restrictions prevail, and a war of tariffs is introduced, the agriculture of the old state, and with it its national strength, is preserved, but its export of manufactures to the adjoining states is checked, and they establish growing fabrics for themselves. Whichever effect takes place, the object of nature in the equalization of industry, the limitation of aged communities, and the dispersion of mankind, is gained, in the first, by the ruin of the old empire from the decay of its agricultural resources; in the second, by the check given to its manufacturing prowess, and the transference of mercantile industry to its younger rivals.