Discusses loan of cirripede specimens from the British Museum.

CD asks if he may have the use of the cirripedes JS collected in Portugal. He will need to break up or make a section of at least one of each species.

Expresses admiration for JS’s paper on Malta ["On recent depressions in the land", Q. J. Geol. Soc. Lond. 3 (1847): 234–40], with its striking demonstration of the change of level between land and water there discovered.

Invites GRW to a dinner party with other scientists.

Discusses loan of cirripede specimens from the British Museum and problems of classification. Encloses a note of thanks to be laid before the Trustees [see 1153].

CD cannot find the lagoon-island mud that WCW asked about, but he sends other geological specimens he hopes will be interesting.

Comments on apology by Chambers for using some of CD’s material without acknowledgment in discussing Glen Roy. His opinion of Chambers’ book [Ancient sea-margins (1848)].

Comments on Ann Susan Horner’s escape in a dangerous incident at sea.

Compares addresses by William Buckland and CL, delivered at recent meeting of the Geological Society.

Discusses the views on Glen Roy in Chambers’ Ancient sea-margins [1848].

Speculates that Chambers wrote Vestiges [of creation (1844)].

Mentions returning borrowed book by Camillo Ranzani.

Discusses loan of cirripede specimens from British Museum. "In truth never will a mountain in labour have brought forth such a mouse as my book on the Cirripedia. It is ridiculous the time each species takes me."

Describes his cirripede work. Asks whether HM-E can arrange for him to borrowspecimens, especially of species described in Dumont d’Urville, Voyage of"Astrolabe" [1830–2]. Lists species that interesthim.

Compliments HM-E on his Crustacés [1834–40].

Thanks JWL for the use of a schoolroom.

Arranges to meet JWL’s son [John] to discuss use of microscope.

Mentions illness.

Thanks JWL for his paper ["Shooting stars", London Edinburgh & Dublin Philos. Mag. 32 (1848): 81–8, 170–2; 35 (1849): 356–7].

Mentions illness of Emma Darwin.

Comments on CL’s Second visit to the United States [1849].

His water treatment by J. M. Gully.

CD’s contribution ["Geology"] to J. W. Herschel’s Manual of scientific enquiry [(1849), Collected papers 1: 227–50].

Discusses CL’s Second visit to the United States [1849]. Corrects CL’s error regarding location of Megatherium finds.

Discusses effect of subsidence and elevation on deposits. Cites examples along coasts of South America and Wales. Proposes theory to explain thickness of deposits in south Wales.

Asks CL’s opinion of his theory of "craters of elevation" described in Volcanic islands.

Mentions CL’s comparison of Mississippi beds to the Pampas.

Comments on Poulett Scrope’s views on the separation of basalt and trachyte.

Describes his cirripede work.

Discusses cirripede specimens borrowed from HC.

Agrees to subscribe £1 toward the portrait of a bishop of Norwich.

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.

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.

Discusses J. D. Dana’s Geology [1849]. Pleased that the part on corals confirms his views [Coral reefs (1842)]. Discusses Dana’s observation that in Sandwich Islands lava streams often join dikes at right angles with no cone. Retracts earlier denial of this possibility. Criticises Dana’s view of Australian valleys.

Continues discussion of Dana’s Geology [1849]. Comments on dikes of Hawaiian volcanoes and Dana’s view of craters of denudation. Compares role of sea and rivers in forming valleys. Criticises Dana’s treatment of CD’s account of coral reefs.