Four years after the death of Justinian, A.D. 569, was born at Mecca, in Arabia the man who, of all men exercised the greatest influence upon the human race . . . Mohammed . . .

Every movement in the skies or upon the earth proclaims to us that the universe is under government.

Experimental investigation, to borrow a phrase employed by Kepler respecting the testing of hypotheses, is "a very great thief of time." Sometimes it costs many days to determine a fact that can be stated in a line.

How is it that the Church produced no geometer in her autocratic reign of twelve hundred years?

The scientific study of Nature tends not only to correct and ennoble the intellectual conceptions of man; it serves also to ameliorate his physical condition.

Is it at all surprising that the number of those who hold the opinions of the Church in light esteem should so rapidly increase? How can that be received as a trustworthy guide in the invisible, which falls into so many errors in the visible?

In early life I had felt a strong desire to devote myself to the experimental study of nature; and, happening to see a glass containing some camphor, portions of which had been caused to condense in very beautiful crystals on the illuminated side, I was induced to read everything I could obtain respecting the chemical and mechanical influences of light, adhesion, and capillary attraction.