Summary

CD at first thought GHD should not answer Haughton [see 10689], but Hooker thinks if no correction is made Haughton’s error will be quoted for 20 years. CD is now inclined to agree.

Summary

Recounts some figures relating deaf-mutism and consanguineous marriages.

GHD has failed to be elected to the Royal Society.

Summary

CD believes few or none have attributed deaf-mutism to consanguineous marriages.

Summary

Is frustrated to see, from a paragraph in Nature [18 (1878): 242], that Charles Lagrange has got hold of the same sort of ideas as he has.

Erasmus is unwell.

Summary

Asks for sketches of [Thalia] pistil, in which he is much interested.

Summary

Refers to Charles Lagrange, who is working on the same subject as GHD, but in a fundamentally different way.

Summary

Rejoices that "Lagrange’s case does not seem very bad".

CD is working hard at dissecting Thalia. Has recovered some handiness with microscope.

Summary

Sends drawings of specimens [of Thalia] CD requested.

Summary

Thanks GHD for his drawings [of Thalia]. Some parts need attention.

Summary

Writes to say that the point on which he thought GHD’s drawings were mistaken proves to be an error in his own observation.

Summary

He and Emma rejoice that GHD’s mathematical troubles are at an end. It is miraculous that he unconsciously followed the right course – like composing a sonata by a fluke.

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.

Summary

Rejoices that he should have "staggered" William Thomson so quickly and that the latter should speak of GHD’s "discovery". The internal heat [of the earth] will please geologists and evolutionists.

Summary

Forwards pamphlet (Jules Carret 1878) to GHD.

Summary

Encloses William Thomson’s report on GHD’s paper. Some of it was written in Rayleigh’s hand.

Summary

Delighted with [William Thomson’s] report. "There can be no doubt now about the value of your work." CD has "not been so much pleased for a long time".

Summary

Asks CD if he would screw himself up to inviting A. Newton to Down.

Summary

Thanks CD [for his increased allowance?].

Writes of his tour [in Algeria].

Summary

Thanks him for his efforts. CD cared most about the letter to Thomas Okes [see Erasmus Darwin, pp. 14–15]. "Cannot think who the calumnious article cd have been about [in?] 1802."

Summary

Reginald Darwin’s pleasure at receiving some old family information.