ABSTRACT

First published in Tait’s, XXII o.s. (XVIII n.s.), 1851, in three parts: April, pp. 229–37; May, pp. 311–15 (below, pp. 211–19); and June, pp. 407–12 (below, pp. 220–31). Revised text (with Appendix) in SGG, XIII, Speculations, Literary and Philosophic, 1859, pp. 1–58.