When Agassiz was a poor medical student in Paris, Humboldt visited him. Agassiz says:--
"After a cordial greeting, he walked straight to what was then my library--a small book-shelf containing a few classics, the meanest editions, bought for a trifle, along the quays, some works on philosophy and history, chemistry and physics, his own 'Aspects of Nature,' 'Aristotle's Zoölogy,' 'Linnæus' Systema Naturæ,' in several editions, 'Cuvier's Règne Animal,' and quite a number of manuscript quartos, copies which, with the assistance of my brother, I had made of works I was too poor to buy, though they cost but a few francs a volume....
"It was no doubt apparent to him that I was not over-familiar with the good things of this world, for I shortly afterward received an invitation to meet him at six o'clock in the Galerie Vitrée of the Palais Royal, whence he led me into one of those restaurants the tempting windows of which I had occasionally passed by. When we were seated, he half laughingly, half inquiringly, asked me whether I would order the dinner. I declined the invitation, saying that we should fare better if he would take the trouble. And for three hours, which passed like a dream, I had him all to myself. How he examined me, and how much I learned in that short time! How to work, what to do, and what to avoid; how to live; how to distribute my time; what methods of study to pursue; these were the things of which he talked to me on that delightful evening."
Noble Humboldt! so great that everybody honored and looked up to him; so kindly interested in others that everybody loved him!
In 1827, at the request of his king, Humboldt returned to Berlin, and became chamberlain, with a yearly salary of five thousand thalers. He gave this year, before the university, a course of free, public lectures upon physical geography, sixty nine in all, which afterwards formed the basis of his grandest work, "Cosmos." The first four lectures were a general description of nature; then astronomy, the principal outlines of geology and meteorology, the distribution of plants and animals, the history of the study of our globe, volcanoes, the ocean, the atmosphere, and the human race.
The lectures were crowded and the applause unexampled. A second course, of sixteen lectures, was given to the public in the music hall, the royal family coming with the thousands who gathered each evening.