Ibid. bk. ii. Sect. ix. Prop. 53.

Brewster’s Life of Newton, 1st edit. chap. vii.

Discourse on the Study of Natural Philosophy, p. 151.

Ibid. p. 229.

Novum Organum, bk. ii. Aphorism 36.

Principia, bk. i. Sect. xiv. Prop. 96. Scholium. Opticks, Prop. vi. 3rd edit. p. 70.

Airy’s Mathematical Tracts, 3rd edit. pp. 286–288.

Jamin, Cours de Physique, vol. iii. p. 372.

Young’s Lectures on Natural Philosophy (1845), vol. i. p. 361.

Paris, Life of Davy, p. 274.

Opus Majus. Edit. 1733. Cap. x. p. 460.

Newton’s Opticks. Third edit. p. 249.

Brewster. Treatise on New Philosophical Instruments, p. 266, &c.

Roscoe, Bakerian Lecture, Philosophical Transactions (1868), vol. clviii. p. 6.

Life of Faraday, vol. ii. p. 104.