Pp. 55–59, 81–86.

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.

Philosophical Transactions [1870], vol. 160, p. 497. Proceedings of the Royal Society, vol. xviii. p. 166, Jan. 20, 1870. Nature, vol, i. p. 343.

Syllabus of a proposed system of Logic, §§ 57, 121, &c. Formal Logic, p. 66.

Lectures on Metaphysics, vol. iv. p. 369.

Bowen, Treatise on Logic, Cambridge, U.S., 1866; p. 362.

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.