oxygen, and hydrogen which were aggregated into particles of wood. Such are the vicissitudes of an atom, now literally as free as the air, now a captive in the tissues of a living organism! A second time the hidden processes of life had compelled me to part with my liberty.
“I have already alluded to the mutability of the earth’s surface. The disturbances that took place during the time that I was a vegetable atom were of a very extraordinary character. The group of islands upon which the monster ferns and mosses flourished, sank beneath the waves, and in course of time they became overlaid with beds of rock, formed by the deposition of sand, clay, and other materials at the bottom of the ocean, the sedimentary matter being hardened by heat and pressure. Human beings talk of the stability of the earth, but we atoms know very well that its great characteristic is instability. Why! the crust of this so-called immovable earth is continually bulging out in some places and falling in others!
“I did not lead a very merry life in the depths of the earth, but still I did not repine. Experience had taught me that I was a creature of circumstance, and must submit to my destiny. How long I remained underground I cannot say. Millions of years may have flown by, but they brought me no change. Numberless atoms of oxygen and hydrogen that were associated with me in the living plant, forced their way between the molecules of the over-
