Extracts from Letters to Henslow, taken from ten letters Charles Darwin wrote to John Stevens Henslow from South America during the second survey expedition of HMS Beagle, were read to the Cambridge Philosophical Society on 16 November 1835 by Henslow and Adam Sedgwick, followed on 18 November by geological notes from the letters which Sedgwick read to the Geological Society of London. On 1 December 1835 they were printed as a pamphlet for private distribution.