They had lived a common intellectual life in this way for about three months, almost every day spending several hours reading original essays, written in different languages, on science and philosophy,--the theory of atoms, molecular physics, organic chemistry, thermo-dynamics, and the different sciences whose object is the knowledge of existence,--or in discoursing upon the real or apparent contradictions of hypotheses; sometimes finding statements and coincidences most remarkable for their scientific axioms, in the books of purely literary writers, and occasionally astonished at the foresight of some great authors. These readings, investigations, and comparisons had especially interested them by the discrimination which their minds were led to make, as they became more and more enlightened, between nine tenths of the writers whose works are absolutely worthless, and half of the last tenth, whose writings have but a superficial value. Having thus cleared the field of literature, they took great delight and satisfaction in the restricted society of superior minds. Perhaps mixed with it was a little feeling of pride. One day Spero arrived earlier than usual. "Eureka!" he cried. But correcting himself quickly, added, "Perhaps." Leaning against the chimney-piece, where a bright fire crackled, while his companion looked at him with her large eyes full of curiosity, he began to speak with a sort of unconscious solemnity, as though he were discussing something with his own mind in the solitude of the woods. * * * * * "What we see is only apparent. Reality is quite different. "The sun apparently turns about us, rising every morning, setting at night; the earth where we are seems to be motionless: but the contrary is the truth. We live on a whirling projectile, thrown into space with a speed seventy-five times as great as that which carries a cannon-ball. "Our ears are pleased by a harmonious concert. Sound does not exist; it is merely an impression of the senses produced by vibrations of a certain size and rapidity on the air, which in themselves are silent. There would be no sound without the acoustic nerve and the brain. In reality there is nothing but motion. "The rainbow spreads its radiant circle; the rose and corn-flower, dripping with rain, glitter in the sun; the green meadow, the golden furrow, diversify the plain with their bright colors. There are no colors; there is no light,--there is nothing but the ether waves, which cause a vibration of the optic nerve. Appearances are deceitful. The sun warms and fertilizes; fire burns. There is no heat, only sensation; heat, like light, is but one form of motion,--invisible but supreme, sovereign motion! * * * * *