[331] "Unity of Worlds," p. 230.
[332] Tyndall.
[333] By the statical properties of matter we understand extension, limit, position, impenetrability, and inertia. We have no idea that there is a vis inertiæ in matter. Vis inertiæ is a forceless force, which is an absurdity. Inertness in matter is not a force, but the opposite of a force—a passivity which requires a force in order to change.
[334] Faraday, "Correlation and Conservation of Forces," p. 368.
[335] Clerk Maxwell, in Nature, vol. ii. p. 421; Herschel, "Familiar Lectures on Science," p. 467.
[336] Professor Norton, in the American Journal of Science and Arts, July, 1864, p. 64; Herschel, "Familiar Lectures on Science," p. 467; Dr. Carpenter, "Human Physiology," p. 542.
[337] Revue des Deux Mondes, 1867.
[338] Anaxagoras.
[339] Dr. Carpenter, in Nature, vol. vi. p. 312.
[340] Herschel, "Familiar Lectures on Science," p. 467.