Explains discrepancies in weights and measures caused by changes since 1836 in apothecaries’ measures.

EC has found that a discrepancy in A. W. von Hofmann’s experiments with iodine solutions resulted from an error in Hofmann’s use of decimals.

Reports S. P. Woodward’s opinion of the Origin: "a very sad book, it unsettles all one’s religious principles and the worst of it is so much of it is true".

Thanks for information about the weight of water.

Describes experiments on Drosera.

CD may be interested in a reference to a method of detecting 1/195000 of a grain of sodium chloride.

Also, on Drosera, suggests it would be interesting to try substances such as gun-cotton, in which nitrogen is in very different states from a salt of ammonia.

Asks him to thank A. S. Taylor for note.

Describes experiments on Drosera.

Discusses reviews of the Origin. By far the best is by Asa Gray.

Discusses plans for new edition of Origin.

Thanks for railway map.

Surprised about Richard Owen: "I thought his courage was as indomitable as his malignity."

Sends extract [Sir John Herschel, "Physical geography", from the Encyclopaedia Britannica (1861)].

Obliged for the Theophrastus. Will return it.

Comments on presentation copy of Orchids: bee Ophrys self-fertilisation; origin of nectar; odour of orchids. Book gives strong cases for special creationists.

Walter White [Asst.-Sec. and Librarian, Royal Society] has introduced EC to Richard Kippist of the Linnean Society, who has made little progress toward accepting Origin.

Son [Leonard] ill with scarlet fever. Also Mrs Darwin.

Intends to give up work on Drosera until Variation is done.

CD’s Linum paper [Collected papers 2: 93–105].

Sending up-to-date railway map of southern region.

Thanks for maps.

George [Darwin] failed at St John’s [College, Cambridge] and will stay another year at school.

Requests letter of introduction to Asa Gray.

Went to Linnean Society to hear CD’s Lythrum paper read [Collected papers 2: 106–31].

Impressed by Fritz Müller’s argument for natural selection in air-breathing apparatus of crustaceans ["The Darwinian hypothesis supported by observations on Crustacea", Ann. & Mag. Nat. Hist. 3d ser. 15 (1865): 410–16].

Plans to visit CD.

Sends Fritz Müller citation as CD requested.

Huxley is boldly proclaiming his Darwinism at Royal Institution ["Methods and results of ethnology", Not. Proc. R. Inst. G. B. 4: 460–3; also Collected essays 7 (1894)].

May his son George call for advice on his career?

CD has been ill for past four months.

Reading Carl Vogt [Lectures on man (1864)].

Vogt, though anti-Lamarck, is converted to Darwinism.

How did CD handle his sons’ expenses at Cambridge?

Discusses income provided for sons at Cambridge.

Asks Emma to write to Erasmus [E. A. Darwin] in support of Miss Elizabeth Garrett as Professor of Physiology at Bedford College for girls.

Returns Hooker’s paper [unidentified].