DARWIN, Charles (1809-1882). Naturalist.
Good Autograph Letter Signed to Sir Henry [Holland], 3½ pages 8vo (some light soiling especially to the edges), Down, Bromley, Kent, 6 November [1864]. Thanking him for congratulations (on receipt of the Copley medal), discussing Herbert Spencer's new work and his own health, and commenting on Holland's travels and adventures.
This is clearly the reply to Holland's letter to Darwin of 4 November 1864 (see The Darwin Project in which he expresses his pleasure at Darwin's honour (the Copley Medal had been voted to Darwin on 3 November), welcomes the news, via CD's Brother Erasmus, of his improving health, suggests that he should read 'the discussion of your doctrine' in Spencer's [Principles of] Biology (issued in parts between 1864 and 1867), and mentions his visit to Gibraltar to examine the caves and fossils.
 Sir Henry Holland (1788-1873) was a prominent physician frequently consulted by Darwin. There are twenty-three known letters from Holland to Darwin, but only one in the other direction. The present letter is unknown and unpublished.
It is notable that although Darwin adopts the usual and slightly formal address of 'My dear Sir Henry', Holland himself in the letter to which this is a response addresses him as 'Charles'.
Transcript:

'... I have just read H. Spencer's work; it strikes me as extremely clever, & yet, I cannot tell why, I never feel much wiser, when I have finished reading him.
 'I am, I hope, decidedly getting better, but fear that I shall never reach my former ?modicum of strength: I am, however, able to do a little work in the Natural History every day. I was very ill for about ten months with incessant vomiting, which became bad when you were in America last year. How wonderful your strength & vigour of interest are; I had heard of your Gibraltar expedition. - With most sincere thanks for your never-failing kindness, I remain my dear Sir Henry
 'Yours most sincerely / and obliged / Charles Darwin'

[No: 24740]