Thanks for pamphlet by A. S. Taylor.
"… we have had a terrible week with my poor girl [Henrietta] on the point of death".
Discusses experiments involving placing solutions of ammonia and other substances on leaves of plants.
15 Marine Parade, Eastbourne
I have received in a parcel from Down your letter and most interesting enclosures and Taylor's pamphet. Good heavens, what trouble you have taken for me! I am sure I am very much obliged; and the facts are most interesting to me, but I have not yet digested them.— Since writing last we have had a terrible week with my poor girl on the point of death; but she has rallied surprisingly. When we shall be able to move her home we know not as yet at all.— You ask how my experiments were tried; but they have been tried in so many manners that I hardly know how to answer. I will before very long (but all my work has been utterly stopped for a fortnight by this miserable illness) publish an account.—
When I saw you I had tried only putting a minute drop on the leaves on growing plants
and observing whether or not they contracted as if over a fly.
From many reasons I inferred that the leaves absorbed some nitrogenous element, probably
some form of Ammonia; so I thought I would try under the microscope the effect
of C. of Ammonia; and several other salts and substances, and it is truly
wonderful how quickly a minute dose acts and produces marvellous changes in the
absorbing glands and in the adjoining cells. I have tried plain water over and over
again with no effect. I have over and over again kept a leaf for 1, 2, 3, 4, and
5 hours in water with no effect, and then put these same leaves in a
few measured drops of very weak solutions of C. of Ammonia (all made, and
re-made by myself) and the same peculiar effects were produced in one
hour or 1
I had measured the quantity of weak solution and I counted the glands which had
absorbed the ammonia and were plainly affected; the result convinced me that each gland
could not have absorbed more than
Yours very truly | C. Darwin
- f1 2973.f1Dated by the relationship to the letter from Edward Cresy, 30 October 1860.
- f2 2973.f2See letter from Edward Cresy, 30 October 1860 and enclosure. Cresy also forwarded to CD the letter from A. W. von Hofmann to Edward Cresy, 27 October 1860. The pamphlet by Alfred Swaine Taylor was probably Taylor 1860, which discussed chemical tests for arsenic and antimony. There is a note on this work in DAR 60.1: 69.
- f3 2973.f3Cresy and his wife visited Down on 18 September 1860, shortly before the Darwins left for Eastbourne (Emma Darwin's diary). CD's notes on his observations on Drosera and Dionaea, begun in July 1860, are in DAR 54, 60.1, and 60.2.
- f4 2973.f4CD's initial observations on the cytological phenomenon of the `aggregation of protoplasm' are in DAR 60.1: 77--81.