To J. S. Henslow 10 November 
My dear Henslow.
We return home this afternoon, as my poor dear girl is now just strong enough to bear removal.— I received your letter forwarded from Down this morning, & very much obliged I am to you for having taken so much trouble about Dr. Bree.1 I had thought I would have inserted a letter in some Journal on so unprovoked attack on my veracity; but I am glad I did not. No one would ever have dreamed of his interpretations. Again I sincerely thank you.—
I never heard of such a muddle about the stone Hatchets.2 If you are sure that you can spare & know no one else who would make better use of B. de Perthes Book, I shd like to have a copy.3 His course of investigation has been a strange one.—
On my return home I will settle about the seeds.—
I am still at work on Drosera. I asked you about the moving red matter in the cells, & now for the chance of your knowing, I want to ask one other question; but please observe if I get no answer I shall understand that you do not know.— My question is whether, observations have been made on the action of weak solutions of Carb. of Ammonia (or of other salts) on the fluid contents of the cells of living plants.— I find that C. of Ammonia has a remarkable & rapid action when absorbed by the roots.
My dear Henslow | Ever yours gratefully | C. Darwin
The stone hatchets are a great muddle. Would like a copy of Jacques Boucher [de Crèvecoeur] de Perthes’s book [Antiquités Celtiques et antédiluviennes (1847–64)].
Is studying action of carbonate of ammonia on Drosera. Asks if this has been done.
Please cite as
Darwin Correspondence Project, “Letter no. 2981,” accessed on 17 January 2017, http://www.darwinproject.ac.uk/DCP-LETT-2981