OERSTED, the great natural philosopher, has lately published at Leipzic, under the title of _Der in Geist in der Natur_ (Spirit in Nature), a collection of remarkable essays which he has written, at various times, during a series of years. The purpose he has followed through his entire scientific career, has, perhaps, its most complete expression in this book. It is the demonstration of the same laws in physical nature as in the higher spheres of the reason and intelligence. On the principle of the essential unity of all things, he seeks not only to lay the foundation of a universal science, but to afford some views of the superstructure. The work contains eight distinct essays: the first, "The Spiritual in the Corporeal," is in the form of a Dialogue, and aims at a reconciliation of the conflicting modes of thought, by which the universe is assumed to be essentially material, or essentially spiritual; the second, "The Fountain," treats of the impressions of beauty produced by the great, sublime, and powerful; the third considers the relation to the imagination, of the apprehension of nature by the understanding, and shows that it is only imperfect culture and ignorance which can suppose any dissonance between the two. He shows that the progress of science enriches, aggrandizes, and elevates the imagination. The fourth essay is, perhaps, the most interesting of all. Its theme is, "Superstition and Skepticism in their relation to Natural Science." The notion that superstition is favorable to poesy, he dissipates with masterly conclusiveness. The true realm of beauty is the realm of reason. It is true that science deprives the poet of the use of sundry unnatural conceptions, but while it more than compensates him by the substitution of nobler ideas, it opens to him a new, affluent, and little explored poetic world. "It can," he says, "not be charged as a crime upon natural science, that it has destroyed materials hitherto used by the poets. Such losses are of small consequence to the true poet, but may, indeed, be painful to the many dabblers in the poetic art, who think they have rendered the insignificant poetic by tricking it out in gewgaws from the poetic armory of a vanished era." The fifth, entitled, "The Existence of all things in the Domain of Reason," is the profoundest and most significant of these essays, and more than the others brings out in form as simple and popular as could be expected, the fundamental idea of the author's system of thought. It asserts that there is, throughout the universe, a radical unity between the laws of beauty, and man's moral nature and intellectual powers, and that there must therefore exist for the mind, a perfect community of nature and analogy between different worlds, and a rational connection between all thinking beings, not only of the earth, but of other planets and systems. The final essay is on "The Culture of Science as the Exercise