Agrees to pay Mr Mason as requested.

JP’s reference was clear, but seems to be different from the case cited by W. Hopkins about erratic conglomerate boulders. Asks for more details on the latter. CD does not think much of Hopkins’ paper ["Elevation and denudation of the district of the lakes of Cumberland and Westmorland", Q. J. Geol. Soc. Lond. 4 (1848): 70–98].

Thanks JP for his note and reference. CD’s paper will not deal with the general question of erratics but only their transportal from a lower to a higher level ["The transportal of erratic boulders", Collected papers 1: 218–27]. His notion is that the boulders were transported by coast-ice, not drifting icebergs, and that during the period of transportal the land was subsiding. Can JP tell him whether the raised conglomerate boulders he observed were rounded or angular?

Sends MS of his chapter on geology for Manual [Collected papers 1: 227–50]. Fears it may be too long. Does not much like it but can do no better. After hesitation, has recommended books. Defends his point that mere collection of rock specimens is "of hardly any use to Geology".

Cannot give information about hook. Fuegian women fish without hooks.

Robert Mallet’s suggestion about space for specimens on board men-of-war forwarded to Sir J. Herschel.

Describes his new microscope and its advantages for dissecting. Suggests RO might discuss topic [in his contribution to J. F. W. Herschel, ed., Manual of scientific enquiry (1849)].

Sir John Herschel has not received the parcel of "Scientific Instructions", which was posted on the 15th. He requests an accurate search at the Admiralty.

Pleased at RO’s praise of Coral reefs.

Has read with very great interest RO’s "Report on the archetype" [Rep. BAAS 16 (1846): 169–340]. RO should give name to every letter or number in his woodcuts.

Thanks JSH for his address [Address delivered in the Ipswich Museum on 9th March 1848]. Questions a sentence which implies that only the practical use of a scientific discovery makes it worth while. The instinct for truth justifies science without any practical results. Cites his work on cirripedes.

Apologises for length of notes of advice for microscopic work.

CD discusses questions about his coral reef theory that were raised by HTDlaB [in his Geol. Soc. Anniversary Address (1848)].

Some geologists (especially H. T. De la Beche) doubt boulders have really been carried above their parent rock, but rather thought they were left behind as a result of denudation. Asks JP’s view of this, which he can quote. Supposes he will be well abused for his paper, but is resolved "not to show a white feather".

Asks ACR to establish height of Moel Tryfan in Caernarvonshire; "in my notice on this hill [""Ancient glaciers of Caernarvonshire"" (1842), Collected papers 1: 163–71] I give a very much less height than others". [See also another mention of the elevation of Moel Tryfan in "On the transportal of erratic boulders" (1848), Collected papers 1: 218–27.]

Obliged for account of change in quality of wool. "Some authors will not admit that climate has any perceptible action."

Hopes his health is re-established.

Agrees that naval expeditions to the Arctic are a waste of money. Believes Sir J. Barrow responsible. "Dr [Richard?] King is quite right in the advantage of Land Expeditions".

May go to Paris next summer about barnacles.

Unable to appreciate second volume of Alexander von Humboldt’s Cosmos [1848].

Recommends review by Sir John Herschel [Edinburgh Rev. 87 (1848): 170–229].

Recommends book by Mary Somerville [Physical geography (1848)].

Mentions article [on species] by M. E. Chevreul [Ann. Sci. Nat. (Bot.) 3d ser. 6 (1846): 142–214].

Sends MS of "Geology" for Manual [Collected papers 1: 227–50]. First parcel lost. Asks JFWH to give advice on an unclear note, translated from Élie de Beaumont, on measuring incline of lava-flows.

Encloses his £3 subscription to JBI’s Sunday School. Asks to reduce it in the future to £2 per annum.

Has been unwell.

Confident of species theory as result of applying it to cirripede sexual systems.

CD’s opinion of E. Blyth. JDH should meet Blyth, inquire about domesticated varieties, study insular flora, solve coal-plant problem.

Describes colour changes from blue to red in valves of operculum of the cirripede genus Ibla.