Sends £10 subscription for James Murie.

Thanks them for their kind letter and interest in his work. Sends photograph.

Thanks for Indian [Medical] Gazette. Comments on article.

Reports that he has not received JSBS’s book on histology and physiology [Sanderson ed., Handbook for the physiological laboratory (1873)], which Edward Emmanuel Klein told CD’s son was to be sent. He asks for information so that he may thank Dr Klein. [Klein and Michael Foster were co-authors with JSBS.]

He has returned the Gazette to Dr T. L. Brunton. [See 8825.]

The impossibility of conceiving that the universe arose through chance is the chief argument for the existence of God, but CD has never been able to decide whether this is an argument of real value. Safest to believe that the subject is beyond man’s intellect, "but man can do his duty".

Anxious to have GHD come home because of his poor health. Recommends Huxley’s physician (Andrew Clark) – an advocate of milk diet.

Has sent JDH’s letter to Nature ["Perception in ants", Nature 7 (1873): 443–4].

Sons recall kindness received from JDH and others in America.

Wants to discuss raising a testimonial fund for Huxley and whether Huxley would stand this.

Discusses the arrangements being made to present a gift to Huxley [see 8872].

CD will write to William Spottiswoode about the fund for Huxley. CD is raising his subscription to £300. "We have done a good day’s work … [it] gives me a higher opinion of human nature than I had before, though I am not one of those who think lowly of mankind."

Hopes that Charles Lyell has enjoyed his excursion.

Sends JT the list and amounts subscribed for Huxley. It will probably amount to £1800. He will write to Huxley and use every argument he can to make him accept.

Sends to Pantlludw [North Wales] bottle of formic acid. FD and Amy [Darwin] can search for spawn. If found, keep in two basins and add 6 drops of acid to one and look for differences.

Discusses error in CD’s calculation of natural increase of elephants.

Includes extract from Origin.

"Try only 1 or 2 drops of Formic A[cid]."

Photographs sent by JC-B show great power of acting.

David Ferrier’s researches sound wonderful. Does he believe that he excites an idea and this leads to the movement, or that he acts directly on the motor nerves?

Fears all the seeds are dead. Will try with less vapour of formic acid.

The Huxley fund amounts to £1955. CD trembles about THH’s answer.

Writes of his extreme interest in WBC’s article ["On the hereditary transmission of acquired psychical habits", Contemp. Rev. 21 (1873): 779–95].

Encloses note from J. T. Moggridge commenting on JDH’s letter ["Perception in ants", Nature 7 (1873): 443–4].