Has been invited to contribute geological instructions [to J. F. W. Herschel, ed., Manual of scientific enquiry (1849); Collected papers 1: 227–50]. Asks RO whether remarks on coral reefs appertain to geology rather than zoology.

Looks forward to visit by Owens.

Undertakes to write geological part of Admiralty Instructions [A manual of scientific enquiry (1849), Collected papers 1: 227–50]. Has doubts as to his success.

Invites him to dinner on Saturday the 12th. Charles and Mrs Lyell, Edward Forbes, Richard Owen, and Thomas Bell coming also.

"Will you bring your map of S. America … and we will have a talk over it."

Thanks the Trustees of the British Museum for entrusting to him the collection of Cirripedia and allowing him to disarticulate one specimen of each species.

Thanks for present of fossil Balani.

Thanks also for JS’s request to David Landsborough to send barnacle specimens.

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.

Asks for the reference in which JP states that some erratic boulders came from a lower to a higher level. CD is writing a paper ["Transportal of erratic boulders", Collected papers 1: 218–26] in which he believes he has the true explanation. Would like as many instances, with details, as possible.

Though correspondence has never ebbed so low, CD is constantly in his thoughts.

Observations on cheetahs used as domesticated hunting animals.

Finds geographical barriers sometimes separate species, but also finds species that remain separate where there are no barriers to migration.

Colour "individuates" isolated animal species.

Plains and alpine animal distribution show altitude not strictly analogous to latitude.

Impact of timber cutting on climate has led to extinction of crocodiles.

Will discuss coal formation in letter to Edward Forbes.

CD often asked whether isolated mountains in southern latitudes had closely allied representatives of Arctic and north temperate plants; JDH has found a representative barberry.

Making for Darjeeling via Calcutta.

Thanks for sending cirripedes. Cannot make out the label, so can JCR tell him the bank and the depth. Hopes to keep the specimens for 6 or 8 weeks before returning them.

Arranges to pay subscription on 15 Feb and 16 Aug as requested by Mr Mason.

Thanks RC for information on hand-level; he has recommended it in his "Instructions" ["Geology", Collected papers 1: 227–50].

JH's letter grieves him, but he will convey his decision to the Trustees. Has just heard of the death of the Archbishop [of Canterbury, William Howley].

Has been carrying out researches on the reflection of light. Would like JH to communicate his paper on this subject to the R.S.L.

Is grateful for JH's kind offer to look over his paper. Draws JH's attention to certain points. Thinks that the reasoning will please him.

Gives recent observations with the 46" achromatic. G. B. Airy has sent the elements of the recently discovered planets. Latest news of the Governor of the Cape and his diplomatic missions. Mrs. Maclear's sister has come out to visit them and her health and Mrs. Maclear's is improving. R. J. Jones has decided to keep Feldhausen in the family and not sell it.

Arrangements for a meeting with JH.

Has performed experiments measuring the deviation of spectra through an obliquely placed diffraction grating. Believes they strongly support the wave theory of light.

JH must write official letter to Admiralty stating completion of [Cape of Good Hope] telescope and explaining reason for additional £170.