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Darwin Correspondence Project

From Edward Frankland   15 April 1874

14 Lancaster Gate | Hyde Park W.

April 15/74

Dear Mr. Darwin

Herewith I send you a small quantity of phosphate of lime free from animal matter.1 It has not exactly the composition of bone-ash but nearly so. If you would like to try real bone ash, put a small piece of bone in the fire & after an hour or so rake it out, pick out the white portions & crush them to a convenient form for your experiments. I should not anticipate that Drosera could deal with bone-ash so prepared, because it has been made less easily assimilable by the fire.2 The enclosed sample has been precipitated from solution & is therefore in the most favourable condition for assimilation.

I shall be glad to send you some weak sewage water when you are ready for it.3

Believe me | Yours sincerely | E. Frankland


Drosera is the sundew. CD described his experiments with phosphate of lime in Insectivorous plants, pp. 109–10.
CD wanted to test the sensitivity of leaves of Drosera to sewage water (see letter to Edward Frankland, 14 May [1874]).


Insectivorous plants. By Charles Darwin. London: John Murray. 1875.


Sends some phosphates of lime free of animal matter [see Insectivorous plants, p. 109].

Letter details

Letter no.
Edward Frankland
Charles Robert Darwin
Sent from
London, Lancaster Gate, 14
Source of text
DAR 58.1: 49–50
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 9411,” accessed on 25 November 2020,

Also published in The Correspondence of Charles Darwin, vol. 22