DEAR SIR,--The receipt of your Distributio Geographica Plantarum, with the duty of thanking you for a work which sheds so much new and valuable light on botanical science, excites the desire, also, of presenting myself to your recollection, and of expressing to you those sentiments of high admiration and esteem, which, although long silent, have never slept. The physical information you have given us of a country hitherto so shamefully unknown, has come exactly in time to guide our understandings in the great political revolution now bringing it into prominence on the stage of the world. The issue of its struggles, as they respect Spain, is no longer matter of doubt. As it respects their own liberty, peace and happiness, we cannot be quite so certain. Whether the blinds of bigotry, the shackles of the priesthood, and the fascinating glare of rank and wealth, give fair play to the common sense of the mass of their people, so far as to qualify them for self-government, is what we do not know. Perhaps our wishes may be stronger than our hopes. The first principle of republicanism is, that the _lex-majoris partis_ is the fundamental law of every society of individuals of equal rights; to consider the will of the society enounced by the majority of a single vote, as sacred as if unanimous, is the first of all lessons in importance, yet the last which is thoroughly learnt. This law once disregarded, no other remains but that of force, which ends necessarily in military despotism. This has been the history of the French revolution, and I wish the understanding of our Southern brethren may be sufficiently enlarged and firm to see that their fate depends on its sacred observance. In our America we are turning to public improvements. Schools, roads, and canals, are everywhere either in operation or contemplation. The most gigantic undertaking yet proposed, is that of New York, for drawing the waters of Lake Erie into the Hudson. The distance is 353 miles, and the height to be surmounted 661 feet. The expense will be great, but its effect incalculably powerful in favor of the Atlantic States. Internal navigation by steamboats is rapidly spreading through all our States, and that by sails and oars will ere long be looked back to as among the curiosities of antiquity. We count much, too, on its efficacy for harbor defence; and it will soon be tried for navigation by sea. We consider the employment of the contributions which our citizens can spare, after feeding, and clothing, and lodging themselves comfortably, as more useful, more moral, and even more splendid, than that preferred by Europe, of destroying human life, labor and happiness.