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Darwin Correspondence Project

To S. H. Vines   1 November 1881

Down, | Beckenham, Kent. | (Railway Station | Orpington. S.E.R.)

November 1. 1881

My dear Mr Vines

As I know how busy you are it is a great shame to trouble you.— But you are so rich in chemical knowledge about plants, & I am so poor, that I appeal to your charity as a pauper.— My question is, do you know of any solid substance in the cells of plants which glycerine & water dissolves? But you will understand my perplexity better, if I give you the facts.— I mentioned to you that if a plant of Euphorbia peplus is gently dug up & the roots placed for a short time in a weak solution (1 to 10,000 of water suffices in 24 hr.) of Carbonate of Ammonia, the (generally) alternate longitudinal rows of cells in every rootlet, from the root-cap up to the very top of the root, (but not as far as I have yet seen in the green stem) become filled with translucent, brownish grains of matter.1 These rounded grains often cohere & even become confluent. Pure Phosphate & Nitrate of Ammonia produce (though more slowly) the same effect, as does pure Carbonate of Soda.2

Now if slices of root under a cover-glass are irrigated with glycerine & water, every one of the innumerable grains in the cells disappear after some hours.3 What am I to think of this?

My son Frank, when he was at home, maintained that these cells must be modified milk or laticiferous tubes.4 But then, as far as I have yet seen, no such process of aggregation takes place in the stem.— Owing to my confounded ignorance I cannot find the milk tubes in the roots.—

Forgive me for bothering you to such an extent; but I must mention that if the roots are dipped in boiling water, there is no deposition of matter, & Carbonate of Ammonia afterwards produces no effect. I shd. state that I now find that the granular matter is formed in the cells immediately beneath the thin epidermis, & in a few other cells near the vascular tissue. If the granules consisted of living protoplasm, (but I can see no trace of movement in them) then I shd. infer that the glycerine killed them & aggregation ceased with the diffusion of invisibly minute particles; for I have seen an analogous phenomenon in Drosera.5

If you can aid me, pray do so, & anyhow forgive me.

Yours very sincerely | Ch. Darwin

It has just occurred to me that I may have put the slices of the stem of Euphorbia after immersion in C. of Ammonia into glycerine & water, for the sake of transparency, & then if granules were formed they would have disappeared.—


CD had discussed his experiments on the root cells of Euphorbia (spurge) with Vines, including the effects of carbonate of ammonia (ammonium carbonate), when he was in Cambridge in late October (see letter to Francis Darwin, 28 [October 1881] and n. 12).
CD’s use of other chemicals, such as phosphate of ammonia (ammonium phosphate), nitrate of ammonia (ammonium nitrate), and carbonate of soda (sodium carbonate) are described in experimental notes dated from August to November 1881 in DAR 62. In his published paper, ‘Action of carbonate of ammonia on roots’, pp. 241 and 258, CD remarked that these chemicals produced similar but less pronounced aggregation in the root cells.
CD tried a number of chemicals, but found that only a mixture of glycerine (glycerol) and water, and a strong solution of caustic potash (potassium hydroxide), would dissolve the granules (‘Action of carbonate of ammonia on roots’, p. 242).
The experiments on roots of Drosera are described in ‘Action of carbonate of ammonia on roots’, pp. 247–8.


‘Action of carbonate of ammonia on roots’: The action of carbonate of ammonia on the roots of certain plants. By Charles Darwin. [Read 16 March 1882.] Journal of the Linnean Society of London (Botany) 19: 239–61.


Asks SHV about nature of granular matter formed in root cells of Euphorbia peplus which have been placed in solution of ammonium carbonate.

Letter details

Letter no.
Charles Robert Darwin
Sydney Howard Vines
Sent from
Source of text
DAR 185: 75
Physical description
ALS 7pp

Please cite as

Darwin Correspondence Project, “Letter no. 13450,” accessed on 7 June 2023,