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Darwin Correspondence Project

To J. D. Hooker   19 April [1855]

Down Farnborough Kent

Ap. 19th.

My dear Hooker

Thank you for your List of R.S. candidates, which will be very useful to me.—1

I have thought a good deal about my salting experiments, & really think they are worth pursuing to a certain extent, but I hardly see the use (at least the use equivalent to the enormous labour) of trying the experiment on the immense scale suggested by you.— I shd. think a few seeds of the leading orders, or a few seeds of each of the classes mentioned by you with albumen of different kinds wd suffice to show the possibility of considerable sea-transportal. To tell whether any particular insular Flora had thus been transported would require that each species shd. be examined. Will you look through these printed lists,2 & if you can mark with red cross, such as you would suggest. In truth I fear I impose far more on your great kindness, my dear Hooker, than I have any claim; but you offered this, for I never thought of asking you for more than a suggestion. I do not think I could manage more than 40 or 50 kinds at a time, for the water I find must be renewed every other day, as it gets to smell horribly: and I do not think your plan good of little packets of cambric, as this entangles so much air. I shall keep the great receptacle with salt-water with the 40 or 50 little bottles, partly open, immersed in it in the cellar, for uniform temperature.— I must plant out of doors, as I have no green House.—

I told you I had inserted notice in Gardeners Chronicle; & to day I have heard from Berkely that he has already sent an assortment of seeds to Margate for some friend to put in salt-water; so I suppose he thinks the experiment worth trying as he has thus so very promptly taken it into his own hands.—3 Reading this over it sounds as if I were offended!!! which I need not say is not so.—

I may just mention that the seeds mentioned in my former note have all germinated after 14 days immersion, except the cabbages all dead, & the Radishes have had their germination delayed & several I think dead; Cress still all most vigorous.— French Spinach, oats, barley, Canary-seed, Borage, Beet have germinated after 7 days immersion.—

It is quite surprising that the Radishes shd have grown, for the salt-water was putrid to an extent, which I cd not have thought credible had I not smelt it myself, as was the water with the cabbage-seed.—

Most truly your’s | C. Darwin

I lean to the notion of taking the list of introduced plants in Asa Gray just as it stands, but wait till I hear from you to calculate: tell me whether you care to hear result.—


Possibly the two catalogues issued in 1855 by John Cattell, seedsman in Westerham, Kent, which are preserved in DAR 46.2: 1–2. They are heavily annotated by CD in ink and pencil. See letter to J. D. Hooker, 13 April [1855], n. 6. There is no evidence that Hooker marked the lists.
Miles Joseph Berkeley also sent a notice to the Gardeners’ Chronicle and Agricultural Gazette, no. 17, 28 April 1855, p. 278. In his notice, Berkeley commented on CD’s request for information and described experiments carried out by immersing bags of seeds in fresh sea-water. These experiments, carried out by a friend, George Henry Hoffman of Margate, were further reported in the Gardeners’ Chronicle and Agricultural Gazette, no. 35, 1 September 1855, p. 580.


Rejects JDH’s suggestion that seed-salting experiments be conducted on huge scale. Only wishes to demonstrate possibility of sea transport, not establishment of any particular insular flora. More seed results.

Letter details

Letter no.
Charles Robert Darwin
Joseph Dalton Hooker
Sent from
Source of text
DAR 114: 129
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 1669,” accessed on 17 May 2021,

Also published in The Correspondence of Charles Darwin, vol. 5