Equally in the history of science and of medicine, 1542 is a starred year, marked by a revolution in our knowledge alike of Macrocosm and Microcosm. In Frauenburg, the town physician and a canon, now nearing the Psalmist limit and his end, had sent to the press the studies of a lifetime--"De revolutionibus orbium coelestium." It was no new thought, no new demonstration that Copernicus thus gave to his generation. Centuries before, men of the keenest scientific minds from Pythagoras on had worked out a heliocentric theory, fully promulgated by Aristarchus, and very generally accepted by the brilliant investigators of the Alexandrian school; but in the long interval, lapped in Oriental lethargy, man had been content to acknowledge that the heavens declare the glory of God and that the firmament sheweth his handiwork. There had been great astronomers before Copernicus. In the fifteenth century Nicholas of Cusa and Regiomontanus had hinted at the heliocentric theory; but 1512 marks an epoch in the history of science, since for all time Copernicus put the problem in a way that compelled acquiescence. Nor did Copernicus announce a truth perfect and complete, not to be modified, but there were many contradictions and lacunae which the work of subsequent observers had to reconcile and fill up. For long years Copernicus had brooded over the great thoughts which his careful observation had compelled. We can imagine the touching scene in the little town when his friend Osiander brought the first copy of the precious volume hot from the press, a well enough printed book. Already on his deathbed, stricken with a long illness, the old man must have had doubts how his work would be received, though years before Pope Clement VII had sent him encouraging words. Fortunately death saved him from the "rending" which is the portion of so many innovators and discoverers. His great contemporary reformer, Luther, expressed the view of the day when he said the fool will turn topsy-turvy the whole art of astronomy; but the Bible says that Joshua commanded the Sun to stand still, not the Earth. The scholarly Melanchthon, himself an astronomer, thought the book so godless that he recommended its suppression (Dannemann, Grundriss). The church was too much involved in the Ptolemaic system to accept any change and it was not until 1822 that the works of Copernicus were removed from the Index. VESALIUS