From G. H. Darwin 10 October 1878
Summary
Recounts the experiments on Fechner’s law he has found in Helmholz; they are on the smallest perceptible differences of illumination. Describes how to test whether plants’ responses to lights are in accordance with it.
| Author: | George Howard Darwin |
| Addressee: | Charles Robert Darwin |
| Date: | 10 Oct 1878 |
| Classmark: | DAR 210.2: 70 |
| Letter no: | DCP-LETT-11722 |
