It has been already stated that Humboldt, previously to leaving Paris, had promised Baudin, that should his projected expedition to the southern hemisphere ever take place, he would endeavour to join it; and also that information received by him at Cuba had induced him to relinquish plans subsequently formed, and re-embark for the continent of South America, with the view of proceeding to Guayaquil or Lima, where he expected to meet the navigators. Accordingly he went to Carthagena, where he learned that the season was too far advanced for sailing from Panama to Guayaquil. Giving up, therefore, his intention of crossing the isthmus of Panama, he passed some days in the forests of Turbaco, and afterwards made preparations for ascending the Rio Magdalena.

This river, from its sources near the equator, flows almost directly north. “Nature,” says a traveller who sailed up it in 1823, “seems to have designedly dug the bed of the Magdalena in the midst of the cordilleras of Colombia, to form a canal of communication between the mountains and the sea; yet it would have made nothing but an unnavigable torrent, had not its course been stopped in many parts by masses of rock disposed in such a manner as to break its violence. Its waters thus arrested flow gently into the plains of the provinces of Santa Martha and Carthagena, which they fertilize and refresh by their evaporation.