Ɛpsilon

To G. H. Darwin   [before 25 October 1881]1

[66 Hills Road, Cambridge.]

George

Ask Lord R. whether gas-men in testing light, exclude the diffused light; for I suppose that they cannot always make the trials in the same room, & therefore with exactly the same amount of diffused light—2

AL

1
The date is established by the relationship between this note and the letter to Julius Wiesner, 25 October 1881.
2
John William Strutt was the third Baron Rayleigh. In recent experiments on the response of plants to light, Julius Wiesner had claimed that the intensity of light was not proportional to the distance of the plant from the source (see Wiesner 1881, p. 78); George suggested that the presence of diffused light might account for Wiesner’s results (see letter to Julius Wiesner, 25 October 1881).

Please cite as “DCP-LETT-12961,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-12961