Louisiana is the name given by the French, to all that extensive tract of land, lying West of the Mississippi River, which was ceded by them to the United States in 1803. The line of its western boundary follows the Sabine River to the 32d degree of north latitude; thence, due north to the Red River; along that stream westerly to the meridian of 100 west longitude; thence due north to the Arkansas River, ascending that to its source; thence due north to the 42d degree of latitude; and along that, parallel to the Pacific Ocean. Its northern boundary is a matter of dispute between the United States and Great Britain, and the discussion, at the present moment is somewhat exciting and ominous. It is the only question in relation to any part of our border, which has not been amicably adjusted by treaty. _We_ claim the boundary formed by a line drawn from the Lake of the Woods, in the 49th degree of latitude, due west to the Rocky Mountains, thence to the parallel of 54, and on that to the Pacific. The British, on the other hand, claim that part, lying west of the Rocky Mountains, and north of the 46th parallel, or the latitude of the Columbia River. Our claim to the whole of this Territory, the part in dispute being called the Oregon, is based upon priority of discovery, and purchase. The British claim the northern portion by right of possession. The question has been held in suspense for several years, under a treaty of joint occupancy, which is now about to terminate. The question of ownership and jurisdiction, will probably be adjusted definitely in the course of a few years. We trust it may be done without the necessity of an appeal to arms. The vast domain, included within the above named boundaries, contains more than twelve hundred thousand square miles. It is about six times the size of France, and nearly twice as large as the whole territory embraced in the thirteen original States of the Union--an empire, in itself sufficiently extensive to satisfy the ambition of any ordinary people. The discoveries of Columbus, and his immediate successors, were confined to the islands in and about the Gulf of Mexico, and a part of the adjacent coast of the two Continents. The immense tracts that lay inland, stretching thousands of miles towards the setting sun, were unknown and unexplored for nearly half a century after the landing of the Europeans on this coast. Those of North America were first visited in 1512, by Juan Ponce de Leon, a Spanish adventurer in quest of the FOUNTAIN OF IMMORTAL YOUTH, which the Indians represented as gushing up in one of the Elysian Valleys of the West;--but, unfortunately for him and for posterity, death overtook him before he reached the _Fountain_, and the directions for finding it perished with him. Having made the first land on Pascha _Florida_, or Palm Sunday, he gave the name of Florida to all the country lying to the North and West.