Page:The Harvard Classics Vol. 51; Lectures.djvu/106

 96 and others, provided many important data in the most widely different departments of biology. But natural history lacked the great foundation of accurate descriptive knowledge, arranged in order, that astronomy possessed, and, as a result much of the great work which the biological renaissance began was interrupted for a century. Among the feats of seventeenth-century biology were microscopical studies of the anatomy of both plants and animals (Nehemiah Grew, Malpighi, Leeuwenhoek), the beginnings of embryology (Harvey, Swammerdam), mechanical physiology (Borelli) including recognition of the nature of reflex action by Descartes, experimental studies tending to overthrow belief in spontaneous generation (Redi), and even observations on the physiological action of poisons. In this century, in spite of the admirable work of Robert Boyle, somewhat overestimated in his own day however, chemistry languished under the sway of a false theory. Similarly, heat, electricity, and magnetism were of no great importance, unless the magistral work on magnetism of William Gilbert, physician to Queen Elizabeth, published in 1600, be reckoned.

Two other departments of physical science, however, the study of atmospheric pressure and optics, were more fortunate. Torricelli and Viviani, pupils of Galileo, Otto von Guericke, Pascal, and Boyle investigated the barometer and the pressure of gases and worked up the fundamental conclusions. Optics was investigated by no less men than Newton and Huygens, and at their hands underwent a wonderful practical transformation. But this subject requires a peculiarly subtle theoretical foundation, and the times were not yet ripe even for a Newton to enter the true path of theoretical speculation.

THE EIGHTEENTH CENTURY

The great result of seventeenth-century science was to show the world that simple and exact laws of nature can be discovered. At the time of their discovery the most important thing about Galileo's law of falling bodies and Newton's "Principia" was their amazing novelty. Familiarity with such results of science has bred the modern contempt for superstition and anti-intellectual views concerning the phenomena of nature.