RECORD: Darwin, C. R. n.d. (calculations of quantity of chemicals in aqueous solution). CUL-DAR60.2.109. (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. RN1
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).
109
(1 nil 2 gr to 1 oz.) 1 oz [x] 8 [=] 8 drach [x] 60 [=] 480 minm [x] 20 [=] 9600 — { of my minute drops to the ounce when this is 1 gr to oz.
(1/9600)
But as there was 2 gr to the oz. we have
9600 [÷] 2 [=] 4800 [x] 3 [=] 14400 as 3 glands were touched
(2/9600 = 1/4800 2 gr. to 1 oz)
1 1/2 grs. to 1 oz. of water 9600 [-] 4800 [=] 4800
(1.5 / 9600)→ = (1/6400 [x] 3 [=] 25,200) — applied to 3 glands
My minute drops are now estimated as 1/20th of a minim.
1 gr to 2 oz of water
as 1 gr to 1 oz contains 1/9600 of a grain
1 gr to 2 oz [x] 2 [=] 19200 — will contain 1/19200 of a grain
Applied to 3 glands each will have } [x] 3 glands [=] 57600
172800 [÷]3 [=] 57600
Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)
File last updated 1 December, 2025