DARWIN, Charles (1809-1882). Letter in the hand of his son George Darwin, subscribed and signed in autograph ('I beg leave to remain, Dear Sir yours faithfully Charles Darwin') to an unidentified correspondent (the director of an aslum for the insane), Down, Beckenham, Kent, 20 January 1874, 3 pages, 8vo, on a bifolium (traces of guards); with an autograph letter signed by George Darwin apparently to the same recipient, Down, 28 January 1874, 2½ pages, 8vo, tipped onto a page from an album.
Darwin supports his son's statistical work on marriages between first cousins: 'My son George Darwin (who is a good mathematician, having been 2nd Wrangler at Cambridge) has been at work for nearly a year in trying ... to discover what proportion of all marriages are between first cousins ... He now wishes to utilize his results by the discovery of the proportion of the offspring of 1st cousin marriages amongst the insane, idiotic, deaf & dumb &c. I have for 30 years considered an answer to this inquiry of great importance'; endorsing the value of the enquiry, whatever its result, and asking if the recipient will be willing to further it by a survey of the patients of 'the large asylum under your charge'. 'The question which my son proposes shd be asked is simply, - "Were your father & mother first cousins or not?". The questioner will doubtless be the best judge of the most suitable way of approaching the subject'; asking, if such a survey be completed, that the results be forwarded to George Darwin at Trinity College, Cambridge. In a postscript, Darwin asks on his son's behalf for additional information on surnames of parents of the patients, and 'if any cases were recorded when the father & mother of a patient, not the offspring of a 1st cousin marriage, bore the same surname'. George Darwin writes on his own behalf eight days later thanking the recipient for the readiness of his compliance with this request, and elucidating the question of whether doubtful cases were excluded from the 314 forwarded to him: 'I should expect amongst the lower classes that there wd be a considerable number of persons ignorant of their parentage ... Your hint ... on phthisis & scrofula is valuable & I shall try to act on it'. (2)