An incredible advance, of which we shall merely record the most important facts, took place in the study of the physical sciences. Three new planets were discovered, Pallas, in 1802, and Vesta, in 1807, by Gibers; Juno, in 1824, by Harding. Enke and Biela first fixed the regular return and brief revolution of the two comets named after them. Schröter and Mädler minutely examined the moon and planets; Struve, the fixed stars. Fraunhofer improved the telescope. Chladni first investigated the nature of fiery meteors and brought the study of acoustics to perfection. Alexander von Humboldt immensely promoted the observation of the changes of the atmosphere and the general knowledge of the nature of the earth. Werner and Leopold von Buch also distinguished themselves among the investigators of the construction of the earth and mountains. Scheele, Gmelin, Liebig, etc., were noted chemists. Oken, upon the whole, chiefly promoted the study of natural history, and numberless researches were made separately in mineralogy, the study of fossils, botany, and zoology by the most celebrated scientific men of the day. While travellers visited every quarter of the globe in search of plants and animals as yet unknown and regulated them by classes, other men of science were engaged at home in the investigation of their internal construction, their uses and habits, in which they were greatly assisted by the improved microscope, by means of which Ehrenberg discovered a completely new class of animalculae. The discoveries of science were also zealously applied for practical uses. Agriculture, cattle-breeding, manufactures received a fresh impulse and immense improvements as knowledge advanced. Commerce by water and by land experienced a thorough revolution on the discovery of the properties of steam, by the use of steamers and railroads. Medical science also progressed, notwithstanding the number of contradictory and extravagant theories. The medical practitioners of Germany took precedence throughout Europe. Animal magnetism was practiced by Eschenmaier, Kieser, and Justin Kerner, by means of whose female seer, von Prevorst, the seeing of visions and the belief in ghosts were once more brought forward. Hahnemann excited the greatest opposition by his system of homoeopathy, which cured diseases by the administration of homogeneous substances in the minutest doses. He was superseded by the cold-water cure. During the last twenty years the naturalists and medical men of Germany have held an annual meeting in one or other of their native cities.