To J. D. Hooker 7 April 
My dear Hooker
I wrote this morning to thank for the Rhododendrums.—
I have begun my seed-salting experiments,1 & I shd be extremely much obliged if you would tell me what kinds you would expect to be most easily killed by sea-water besides the Cruciferæ, which I had thought wd be so, & which you confirmed; I had meant to have asked, but quite forgot, when I last saw you.—2
If you can mention any that are easily procured, as Agricultural or Garden or flower seeds,—please enumerate Just a few.— Secondly will you tell me, at a guess, how long an immersion in sea-water you shd imagine wd kill the more susceptible seeds? Should you expect a week’s fair immersion wd destroy any of them?
I have looked in Lindleys Vegetable K. & understand what is meant.3
Will you be so kind as to send me a brief note in answer, as I may thus be sooner put out of my pain, & end my experiments, which I daresay you think as foolish, as my splendid idea, that the Coal-plants lived in salt-water like mangroves which made you so savage4
Adios | C. Darwin
My notions sometimes bring good; Dr Davy5 has been experimenting at my request, (in order to see how fishes’ ova might get transported) on the retention of vitality; & he found that salmon’s ova, exposed for 3 whole days to open air, & even some sun-shine, & they produced fine young fish. Dr D. has sent a paper to Royal Soc. on the subject.— N.B. Remember to ask about my distinct case of “a lady in N. America” who saw fishes’ spawn adhering to a Ditiscus.6
CD has begun seed-salting experiments. Wants JDH to write which seeds he expects to be easily killed [in salt water].
CD’s idea that coal-plants lived in salt water like mangroves made JDH savage.
Please cite as
Darwin Correspondence Project, “Letter no. 1661,” accessed on 29 September 2016, http://www.darwinproject.ac.uk/DCP-LETT-1661