acquaintance with Schiller and Goethe, and also with Loder, with whom he studied anatomy. From that time he began to make investigations of his own, and these investigations were in a line which he has never approached since, being experiments in physiology. He turned his attention to the newly-discovered power by which he tested the activity of organic substances; and it is plain, from his manner of treating the subject, that he leaned to the idea that the chemical process going on in the living body of animals furnished a clew to the phenomena of life, if it was not life itself. This may be inferred from the title of the book published in 1797--"Ueber die gereizte Muskel und Nervenfaser, mit Vermuthungen ueber den chemischen Process des Lebens, in Thieren und Pflanzen." In these explanations of the phenomena we have the sources of the first impulses in a direction which has been so beneficial in advancing the true explanation of the secondary phenomena of life; but which, at the same time, in its exaggeration as it prevails now has degenerated into the materialism of modern investigators. In that period of all-embracing activity, he began to study astronomy. His attention was called to it by Baron Von Zach, who was a prominent astronomer of the time, and who at that time was actively engaged upon astronomical investigations in Germany. He showed Humboldt to what extent astronomy would be useful to him, in his travels, in determining the position of places, the altitude of mountains, etc. So prepared, Humboldt now broods over his plans of foreign travel. He has published his work on the muscular and nervous fibre at the age of twenty-eight. He has lost his mother; and his mind is now inflamed with an ungovernable passion for the sight of foreign and especially tropical lands. He goes to Paris to make preparation by securing the best astronomical, meteorological and surveying instruments. Evidently he does not care where he shall go, for on a proposition of Lord Bristol to visit Egypt he agrees to it. The war prevents the execution of this plan, and he enters into negotiations to accompany the projected expedition of Captain Baudin to Australia; but when Bonaparte, bent on the conquest of Egypt, started with a scientific expedition, Humboldt wishes to join it. He expects to be one of the scientific party, and to reach Egypt by way of Barbary.