From Hensleigh Wedgwood   [1867–72]1

I think that a brown study is merely another version of the same metaphor which speaks of a sombre countenance, ein düsteres gesicht2 Heiter and düster express chearful and moody as being open to light and external influences or closed and shut up within itself.3

The date range is established from the relationship between this letter and the first letter from Hensleigh Wedgwood, [1867–72]
CD used the phrase ‘in a brown study’ for abstraction and meditation in Expression, p. 228.
Wedgwood was a philologist: the italicised words (except for ‘sombre’) are German.

Please cite as “DCP-LETT-7042,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-7042