Answers a number of queries from Lyell concerning geography and geology of Chiloé Island and its relationship to the Cordilleras.

Asks about "perched rocks" on Jura and notes their relevance to Louis Agassiz’s theory. Discusses Agassiz’s view on Jura.

Mentions seeing Robert Brown.

Notes R. I. Murchison’s discovery of shells in central England.

Weakness of negative evidence.

Discusses the role of ice in determining the geological features of the Jura. Mentions view of Agassiz. Objects to idea of "a [sea of ice] carrying rocks". Notes Agassiz’s earlier view of "ice expanded in the line of the Great Swiss Valley". Comments on Pentlands.

Defends his theory [in "Parallel roads of Glen Roy" (1839), Collected papers 1: 87–137] against the view that the "roads" were formed by glacial action.

Discusses at length Louis Agassiz’s book [Études sur les glaciers (1840)] and Agassiz’s explanation of moraines. Defends his own theory of the importance of floating ice. Relates glacier theory to his own interpretation of Glen Roy.

Mentions a paper he is writing on South American boulders and till [Collected papers 1: 145–63].

Discusses various types of coral reefs on which he has been collecting notes. Views of C. G. Ehrenberg. His conception of the formation of Bermuda.

Pessimistic about the effect of his poor health on his scientific work.