DISCOVERIES IN ASTRONOMY AND CHEMISTRY. Once fairly introduced, discovery and invention have unceasingly advanced at an accelerated pace. Each continually reacted on the other, continually they sapped supernaturalism. De Dominis commenced, and Newton completed, the explanation of the rainbow; they showed that it was not the weapon of warfare of God, but the accident of rays of light in drops of water. De Dominis was decoyed to Rome through the promise of an archbishopric, and the hope of a cardinal's hat. He was lodged in a fine residence, but carefully watched. Accused of having suggested a concord between Rome and England, he was imprisoned in the castle of St Angelo, and there died. He was brought in his coffin before an ecclesiastical tribunal, adjudged guilty of heresy, and his body, with a heap of heretical books, was cast into the flames. Franklin, by demonstrating the identity of lightning and electricity, deprived Jupiter of his thunder-bolt. The marvels of superstition were displaced by the wonders of truth. The two telescopes, the reflector and the achromatic, inventions of the last century, permitted man to penetrate into the infinite grandeurs of the universe, to recognize, as far as such a thing is possible, its illimitable spaces, its measureless times; and a little later the achromatic microscope placed before his eyes the world of the infinitely small. The air-balloon carried him above the clouds, the diving-bell to the bottom of the sea. The thermometer gave him true measures of the variations of heat; the barometer, of the pressure of the air. The introduction of the balance imparted exactness to chemistry, it proved the indestructibility of matter. The discovery of oxygen, hydrogen, and many other gases, the isolation of aluminum, calcium, and other metals, showed that earth and air and water are not elements. With an enterprise that can never be too much commended, advantage was taken of the transits of Venus, and, by sending expeditions to different regions, the distance of the earth from the sun was determined. The step that European intellect had made between 1456 and 1759 was illustrated by Halley's comet. When it appeared in the former year, it was considered as the harbinger of the vengeance of God, the dispenser of the most dreadful of his retributions, war, pestilence, famine. By order of the pope, all the church-bells in Europe were rung to scare it away, the faithful were commanded to add each day another prayer; and, as their prayers had often in so marked a manner been answered in eclipses and droughts and rains, so on this occasion it was declared that a victory over the comet had been vouchsafed to the pope. But, in the mean time, Halley, guided by the revelations of Kepler and Newton, had discovered that its motions, so far from being controlled by the supplications of Christendom, were guided in an elliptic orbit by destiny. Knowing that Nature bad denied to him an opportunity of witnessing the fulfillment