[6] Report, Brit. Assoc., Cork, 1843, Sect. p. 60.
[7] Quart. Geol. Journ., vol. iii, p. 87, 1847.
[8] On the Origin of Slaty Cleavage, by H. C. Sorby, Edin. New Phil. Journ., 1853, vol. lv, p. 137.
[9] Sorby, as cited above, p. 741, note.
[10] Tyndall, View of the Cleavage of Crystals and Slate rocks.
[11] Darwin, Volcanic Islands, pp. 69, 70.
[12] Norske Mag. Naturvidsk., vol. i, p. 71.
[13] Memoir read before the Geol. Soc. London, Jan. 31, 1855.
[14] H. C. Sorby, Quart. Geol. Journ., vol. xix., p. 401.