Discusses CD’s Glen Roy paper; would like to see the theory put beyond dispute. Tells of Mr Stables’ observations on the parallel roads. Discusses geological features of Scotland which he is sure are marine in origin.

Comments on CD’s paper on South American volcanoes [Trans. of the Geol. Soc. of London, 2d ser., pt 3, 5 (1840): 601–31]. Jets of steam or flame issuing from the side of a hill in Glen Almond.

Thanks CD for a copy of his Journal of researches which is "not second in interest and instruction to any work of the kind I have ever read".

Thanks CD for information about Captain Tillard’s account of the volcanic eruption in the Azores in 1811.

Gives CD the results of some calculations for "dip" over different distances, as requested.

Reference to W. Smellie’s Natural history [1791] requested by CD.

Would like further experimentation to confirm report about germination of wheat from Egyptian tombs. Sir G. Wilkinson may have been deceived by the Arabs.

Reports on abortive anthers in flowers of thyme sent by CD.