In the second place there are now preparing two expeditions of natural history, one by M. de Humboldt, with whose reputation you are surely familiar,--the same who spent several years in exploring the equatorial regions of South America, in company with M. Bonpland. He has been for some years at Berlin, and is now about to start on a journey to the Ural Mountains, the Caucasus, and the confines of the Caspian Sea. Braun, Schimper, and I have been proposed to him as traveling companions by several of our professors; but the application may come too late, for M. de Humboldt decided upon this journey long ago, and has probably already chosen the naturalists who are to accompany him. How happy I should be to join this expedition to a country the climate of which is by no means unhealthy, under the direction of a man so generally esteemed, to whom the Emperor of Russia has promised help and an escort at all times and under all circumstances. The second expedition is to a country quite as salubrious, and which presents no dangers whatever for travelers,--South America. It will be under the direction of M. Ackermann, known as a distinguished agriculturist and as Councilor of State to the Grand Duke of Baden. I should prefer to go with Humboldt; but if I am too late, I feel very sure of being able to join the second expedition. So it depends, you see, only on your consent. This journey is to last two years, at the end of which time, happily at home once more, I can follow with all desirable facilities the career I have chosen. If there should be a place for me at Lausanne, which I should prefer to any other locality, I could devote my life to teaching my young countrymen, awaken in them the taste for science and observation so much neglected among us, and thus be more useful to my canton than I could be as a practitioner. These projects may not succeed; but in the present state of things all the probabilities are favorable. Therefore, I beg you to consider it seriously, to consult my uncle in Lausanne, and to write me at once what you think. . . In spite of the earnest desire for travel shown in this letter it will be seen later how the restless aspirations of childhood, boyhood, and youth, which were, after all, only a latent love of research, crystallize into the concentrated purpose of the man who could remain for months shut up in his study, leaving his microscope only to eat and sleep,--a life as sedentary as ever was lived by a closet student. FROM HIS FATHER. ORBE, February 23, 1829.