The Complete Work of Charles Darwin Online

RECORD: Darwin, C. R. 1873.08.13. tried with Sulphuric Ether & Alcohol cabbage sea-kale – Tropaeolum. CUL-DAR66.5-6. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)

REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 3.2023. 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 volume CUL-DAR66 contains notes on 'bloom'. Francis Darwin explained: "His researches into the meaning of the 'bloom,' or waxy coating found on many leaves, was one of those inquiries which remained unfinished at the time of his death. He amassed a quantity of notes on the subject". LL3: 339. See an Introduction to these folders by Christine Chua & John van Wyhe.

[5]

Augst. 13th/73/ Southampton — tried with Sulphuric Ether & alcohol cabbage, sea-kale— Tropæolum leaves, the under side of Chinese(?) rose against house pods of Peas— fruit of Mahonia & the bloom was instantly removed by the ether & rather less quickly by alcohol — This was well shown by afterwards dipping leaf in water & the glass-case no longer appeared & the part was wetted —

Washed a bit of cabbage-leaf in the Ether & evaporated it on glass slip a thick coating was left, which matted into a globule with slight heat & was plastic & curled like wax when cold.

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Laurel-leaves, the polish on not affected by Ether of alcohol.

Mahonia has upper surface polished & is wetted in water, lower surface silvery; this lower surface removed by ether.

Stock & some other conifer with hairy leaves not at all affected by ether, (having been wholly immersed in ether) when as soon as surface had dried & placed in water, silvery appearance was again seen.

The silvery effect in water here wholly due to fine hairs — which are arrayed with holes, leading, I suppose to the stomata.

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