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.

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.]

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".

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].

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

Has been unwell.

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.

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.

Reports on his father’s health, and Catherine’s. CD, himself, has been a little sick.

Hensleigh [Wedgwood] thinks he has settled the free-will question – "we have none whatsoever".

His health not good.

Has been reading John Evelyn’s Life of Mrs Godolphin, and Mme Sévigné.

Family news. Finds Shrewsbury too noisy.

Anxiety about R. W. Darwin’s health.

Has been unwell but is improving. His father also very ill.

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)].

Congratulates RC on his work on Scottish sea-margins [Ancient sea-margins (1848)].

Discusses Glen Roy; Milne staggered him in favour of the glacier view, but now his opinion has reverted.

Sends two valves of Ibla.

In his chapter [for Manual, Collected papers 1: 227–50], he will strike out any part that JFWH wants struck out, but if much shortening is required it will need rewriting.

Mentions his account; visit to Lincolnshire by his sister [Susan Darwin].

Discusses possible land transactions.