I have seen a picture of the old man, sitting upon a mountain side--above him the eternal snow--below, the smiling valley of the tropics, filled with vine and palm; his chin upon his breast, his eyes deep, thoughtful and calm--his forehead majestic--grander than the mountain upon which he sat--crowned with the snow of his whitened hair, he looked the intellectual autocrat of this world. Not satisfied with his discoveries in America, he crossed the steppes of Asia, the wastes of Siberia, the great Ural range, adding to the knowledge of mankind at every step. His energy acknowledged no obstacle, his life knew no leisure; every day was filled with labor and with thought. He was one of the apostles of science, and he served his divine master with a self-sacrificing zeal that knew no abatement; with an ardor that constantly increased, and with a devotion unwavering and constant as the polar star. In order that the people at large might have the benefit of his numerous discoveries, and his vast knowledge, he delivered at Berlin a course of lectures, consisting of sixty-one free addresses, upon the following subjects: Five, upon the nature and limits of physical geography. Three, were devoted to a history of science. Two, to inducements to a study of natural science. Sixteen, on the heavens. Five, on the form, density, latent heat, and magnetic power of the earth, and to the polar light. Four, were on the nature of the crust of the earth, on hot springs earthquakes, and volcanoes. Two, on mountains and the type of their formation. Two, on the form of the earth's surface, on the connection of continents, and the elevation of soil over ravines. Three, on the sea as a globular fluid surrounding the earth. Ten, on the atmosphere as an elastic fluid surrounding the earth, and on the distribution of heat. One, on the geographic distribution of organ ized matter in general. Three, on the geography of plants. Three, on the geography of animals, and Two, on the races of men. These lectures are what is known as the Cosmos, and present a scientific picture of the world--of infinite diversity in unity--of ceaseless motion in the eternal grasp of law. These lectures contain the result of his investigation, observation, and experience; they furnish the connection between phenomena; they disclose some of the changes through which the earth has passed in the countless ages; the history of vegetation, animals and men, the effects of climate upon individuals and nations, the relation we sustain to other worlds, and demonstrate that all phenomena, whether insignificant or grand, exist in accordance with inexorable law. There are some truths, however, that we never should forget: Superstition has always been the relentless enemy of science; faith has been a hater of demonstration; hypocrisy has been sincere only in its dread of truth, and all religions are inconsistent with mental freedom.