RECORD: Darwin, C. R. [1873].09.25. Lactic / malic / iodic / phosphoric / uric / hipparic / hydriolic acids. CUL-DAR56.66-68. (John van Wyhe ed., 2002-. The Complete Work of Charles Darwin Online, http://darwin-online.org.uk/)

REVISION HISTORY: Text prepared and edited by John van Wyhe. RN2

NOTE: See record in the Darwin Online manuscript catalogue, enter its Identifier here. Reproduced with permission of the Syndics of Cambridge University Library and William Huxley Darwin. The volumes CUL-DAR 54-61 contain material for Darwin's book Insectivorous plants (1875).


66

(6D

Lactic Acid    Sept 21'    8. 27' 3 leaves old red    1 gr to 1 oz (1 & 1/2 dr in all cases )

   (9. 15 (+) 33 (=) 48 fluid coloured pink )

(4° 50', one leaf made a little inflection; the others fully expanded, but all glands so very pale pink colour — I think leaf killed—

   put into Phosphate of Ammonia 1 gr to 20 oz— after washing it.—

   Fluid coloured strong pink — I never saw colour extracted before without inflection)

Sept 22d    8. 20'    glands in the same state; but I think there has been a little inflect from the Phosphate, for all 3 leaves show some inflection, but no segregation.) (23d same state— a very few tents of which glands not injured are segregated)

21'    8. 34    Malic A    same strength & leaves

   4° 55' no clear effect

(Sept 22d 8. 35', 2 leaves with much inflection, the 3d with some;— segregation — more inflection than can be accounted for by water — no changing mucus

   Put into pure water) (Sept 23d 4° same state)

(Sept 24th    9.    all 3 leaves pretty fully expanded    glands darkened)    so clearly not killed

8. 30;    Iodic A    do    do    do    do    do

(10. 34', after 2h, 2 die 2 leaves decidedly inflected) (11. 20', aft 3h strongly inflected)

(12. 30 aft 4 tentacles of glands dark brown & not black as is common)

(5. do 8h 30' d0—    flaccid—    fluid not coloured — most closely inflected

   4    put into pure water) I do not doubt dead)

Sept 23d    8. 35'    dark leaves, tentacles pales leaves evidently dead

67

(6E

Sept 21    8. 45'    Phosphoric A    1 gr to 1 oz    1 & 1/2 dr    3 red leaves

   2. 15'    a good deal of inflection, some glands pale

   (5. closely inflected — fluid pink — many glands pale pink, put into pure water), a good many more glands not inflected.)

(Sept 22d. 8. 40 — still closely inflected — all the glands, except some on disc quit pale) (23rd same state)

(Sept 24'    9.    same state    I do not doubt killed)

437.7 (x) 2 (=) 875.0

21'    8. 53'    Uric Acid    1 gr to 2 oz, but not all dissolved, so gave 3 leaves 3 dr of the solution (sol milk warm)— 3 very good leaves

   9. 15    decided inflection (12. 35' — inflection not very energetic)

   5. sub-inflected — marginals not inflected, sub-marginals & outer discals inflected — glands not discoloured — water not coloured — put into pure water — great quantity of mucus secreted

Sept 22d    8. 40' — all 3 leaves almost fully reexpanded, exciting the outer part of disc which in water are so often inflected

Sept 22d    8. 20'    Hipparic A (Dr Moore) — 4 leaves 1 g to 1 oz    2. dr of do — (2 leaves pale & 2 red.

(10. 15' fluid pink    glands somewhat discoloured — no inflection)

(11. O) inflection glands very pale)

(2. 30'  1 leaf much inflected, 2 considerably, one very little)

(5°.    (illegible) day 2 considerably & 2 very little)

(5. all 4 leaves all much inflected, & 2 closely— very much mucus secreted washed & put into pure water — glands all very pale

(Sept 24th    9.    do    do    do    glands excessively pale I do not doubt killed)

68

(6F

Hydriodic A.    Sept 25' 10 18' — 3 red leaves in sol.    1 gr to 1 oz water

(10. 40' ,O) (11°, O inflection fluid pinkish, glands discoloured)

(12. 50', some inflection of sub-marginals — they look finer than those were in Benzoic A) wonderful lot of mucus secreted) (3. closely inflected all 3 leaves.) glands colourless.)

(5. immense mucus— washed & put into pure water)

(Sept 26th    8. closely inflected)

― 30th    do    evidently quite long dead

do. A.    10. 23'    4  3 red leaves in sol of 1 gr to 2 oz of water

(11., O effect) (11. 30' a trace of pink in fluid

(12°, 40' a trace of inflection mucus as above in sub-marginals, fluid pink.)

(3°, some slight, but decided inflection; glands colourless except those on centre of discs, which are still red in all 3 leaves — showing that these have some different property from the outer ones)

   (5. very slightly sub-inflected — some glands in very centre still red)

Sept 26.    8. a m    all 4 leaves closely inflected, in one leaf few glands in centre still red; fluid pink— very much mucus— put into fresh water)

Sept 30'    same as above— a great contrast to Hydrochloric Acid


Return to homepage

Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)

File last updated 8 January, 2026