DARWIN, Charles (1809-1882). Naturalist.
Incomplete Autograph Letter Signed ('Ch. Darwin') to [Bartholomew James] Sulivan (1810-1890), 2 page 8vo, ?9 May  (dated in another hand 'May 9th about 1864 or 65'. To the naval officer and hydrographer of HMS Beagle, just about to retire from the Board of Trade, complaining that his ill-health meant that he would only be able to converse with him briefly during a proposed visit.
The present letter is not yet to be found in The Correspondence of Charles Darwin (Cambridge, 19 vols.), but Sulivan's letter of 31 May  is almost certainly the reply to it.
'sit with anyone for more than quarter or sometimes for half an hour. If I talk more my head sings & swims & I am done for. But I shd. in all possibility be able to pay you two or three little visits in the drawing room when you come here; so if you can spare a day do come for I shall be sincerely rejoiced to see you / My dear Sulivan / Yours very sincerely / Ch. Darwin.'Sulivan replied that 'I can only run down in the middle of the day for an hour or two... . If you are not well enough do not hesitate to say so'. A footnote in the Correspondence indicates that there 'is no evidence that Sulivan visited CD during 1865'. [Darwin Correspondence Database,http://www.darwinproject.ac.uk/entry-4844].
Sulivan had been first appointed to the Beagle by his former shipmate Robert Fitzroy in 1828 and, after being promoted lieutenant, was re-appointed in 1831 and sailed with her on her famous voyage, during which he formed a lifelong friendship with Darwin. After returning to England in 1836 he held several naval commissions and carried out an important survey of the Falkland Islands. He retired with the rank of rear-admiral but was subsequently knighted in 1869 and appointed admiral in 1877.
The image links to a larger or more detailed version.