The Physical Earth presents to us, in every form of organic and inorganic matter, an infinite variety of phenomena. If we select specimens of rocks, either crystalline or stratified,--of metals in any of their various combinations with oxygen, sulphur, and other bodies,--of gems glistening with light and glowing with colour,--if we examine the varied forms and hues of the vegetable world, or the more mysterious animal creations, we must inevitably come to the conclusion, long since proclaimed, and admit that dust they are, and to dust must they return. Whatever permanency may be given to matter, it is certain that its form is ever in a state of change. The surface of the “Eternal Hills” is worn away by the soft rains which fall to fertilize, and from their wrecks, borne by the waters to the ocean, new continents are forming. The mutations of the old earth may be read upon her rocks and mountains, and these records of former changes tell us the infallible truth, that as the present passes into the future, so will the form of Earth undergo an important alteration. The same forces which lifted the Andes and the Himalayas are still at work, and from the particles of matter carried from the present lands by the rivers into the sea, where they subside in stratified masses, there will, in the great future, be raised new worlds, upon which the work of life will go forward, and over which will be spread a vast Intelligence. If we regard the conditions of the beautiful and varied organic covering of the Earth, the certainty, the constancy, of change is ever before us. Vegetable life passes into the animal form, and both perish to feed the future plant. Man, moving to-day the monarch of a mighty people, in a few years passes back to his primitive clod, and that combination of elementary atoms, which is dignified with the circle of sovereignty and the robe of purple, after a period may be sought for in the herbage of the fields, or in the humble flowers of the valley.