an entirely new impulse to the tide of population:  and here it may not be altogether irrelevant, to enter into a short disquisition on the natural superiority possessed by those countries which are most abundantly intersected with navigable rivers.  That such are most favourable for all the purposes of civilized man, the history of the world affords the most satisfactory proof There is not, in fact, a single instance on record of any remarkable degree of wealth and power having been attained by any nation which has not possessed facilities for commerce, either in the number or size of its rivers, or in the spaciousness of its harbours, and the general contiguity of its provinces to the sea.  The Mediterranean has given rise to so many great and powerful nations, only from the superior advantages which it afforded for commerce during the long infancy of navigation.  The number and fertility of its islands, the serenity of its climate, the smoothness of its waters, the smallness of its entrance, which although of itself sufficient to indicate to the skilful pilot the proximity of the ocean, is still more clearly defined by the Pillars of Hercules, towering on each side of it, and forming land-marks not to be mistaken by the timid, the inexperienced, or the bewildered.  Such are the main causes why the Mediterranean continued until the discovery and application of the properties of the magnet, the seat of successive empires so superior to the rest of the world in affluence and power.  It is indeed almost impossible to conceive, how any considerable degree of wealth and civilization can be acquired without the aid of navigation.  From the moment savages abandon the hunter state, and resign themselves to the settled pursuits of agriculture, the march of population must inevitably follow the direction of navigable waters; since in the infancy of societies these furnish the only means of indulging that spirit of barter which is co-existent with association, is the main spring of industry, and the ultimate cause of all civilization and refinement.  In such situations the rude canoe abundantly suffices to maintain the first necessary interchanges of the superfluities of one individual for those of another.  Roads, waggons, etc. are refinements entirely unknown in the incipient stages of society.  They are the gradual results of civilization, and consequent only on the accumulation of wealth and the attainment of a certain point of maturity.  Canals are a still later result of civilization, and are undoubtedly the greatest efforts for the encouragement of barter, and the developement of industry, to which human power and ingenuity have yet given birth.  But after all, what are these artificial channels of communication, these ne plus ultras of human contrivance, compared with those natural mediums of intercourse, those mighty rivers which pervade every quarter of the globe?  What are they to the Danube, the Nile, the Ganges, the Mississippi, or the Amazon?  What