Discusses CL’s refutation of CD’s concept of "craters of elevation" and CL’s new concept of "craters of denudation". Mentions examples of such craters. Admits that his own concept of these craters was unsatisfactory. Urges CL to publish article ["On craters of denudation", Q. J. Geol. Soc. Lond. 6 (1850): 207–34].

Arranges to call on Wednesday but declines a breakfast invitation, as his stomach is so particular that he is afraid to go about before eating.

Encloses a letter to be forwarded to Sven Lovén, asking for a specimen of a remarkable cirripede. Still anxious to receive JGF’s specimens.

To make his monograph on cirripedes complete, would appreciate a specimen of Alepas squalicola, which CD is sure is a new genus.

Asks if Mr Salt could arrange to invest up to £30,000 on his behalf.

Has sent all the fossil pedunculated cirripedes in the Copenhagen collection, together with a letter from Johannes Steenstrup concerning changes he believes are needed in the descriptions.

Criticises Élie de Beaumont’s view of a right angle junction of a stream of lava and a dike.

Mentions his misgivings in voting to recommend J. D. Forbes for Royal Medal.

Notes Daniel Sharpe’s work on mica schist.

He is willing to wait until the end of February 1850 for Mr Salt to find him an opportunity to invest up to £30,000.

Has had his portrait taken;

is anxious about scarlet fever among his children.