Discusses foliation and cleavage. Comments on dip of cleavage laminae in mountains. Mentions views of Sedgwick and Studer. Suggests reading C. L. von Buch [Travels through Norway and Lapland (1813)] "as an amusement". Praises views of William Hopkins. Suggests reading paper by H. D. Rogers ["On cleavage of slate-strata", Edinburgh New Philos. J. 41 (1846): 422–3)]. Comments on the paper.