[78] Formal Logic, p. 124. As Professor Croom Robertson has pointed out to me, the second and third premises may be thrown into a single proposition, D = DeBC ꖌ DEbc.
[79] Pp. 55–59, 81–86.
[80] See his work called The Process of Thought adapted to Words and Language, together with a Description of the Relational and Differential Machines. Also Philosophical Transactions, [1870] vol. 160, p. 518.
[81] Philosophical Transactions [1870], vol. 160, p. 497. Proceedings of the Royal Society, vol. xviii. p. 166, Jan. 20, 1870. Nature, vol, i. p. 343.
[82] Syllabus of a proposed system of Logic, §§ 57, 121, &c. Formal Logic, p. 66.
[83] Lectures on Metaphysics, vol. iv. p. 369.
[84] Bowen, Treatise on Logic, Cambridge, U.S., 1866; p. 362.
[85] The contents of this and the following section nearly correspond with those of a paper read before the Manchester Literary and Philosophical Society on December 26th, 1871. See Proceedings of the Society, vol. xi. pp. 65–68, and Memoirs, Third Series, vol. v. pp. 119–130.
[86] Proceedings of the Manchester Literary and Philosophical Society, 6th February, 1877, vol. xvi., p. 113.
[87] Montucla. Histoire des Mathématiques, vol. iii. p. 373.