In the spring of 1873, Thomas Henry Huxley was facing serious financial difficulties, compounded by overwork and ill health. He had been sued by a neighbour in connection with work that was being done on his new house. He also owed his builder a large sum, due by the end of April (A. Desmond 1994–7, 2: 44–8). Charles and Emma Darwin were staying in London at this time, and on 4 April 1873 Katherine Murray Lyell visited them (Emma Darwin's diary (DAR 242)). Darwin's daughter. Henrietta Emma Litchfield, recalled, ‘Mrs Lyell, in a talk to my mother, during this stay in London, suggested whether a very few of his [Huxley's] most intimate friends might not quite privately join in making him a gift to enable him to get away. My father took eagerly to the idea, and became the active promoter of the scheme’ (Emma Darwin (1904) 2: 262).

In the weeks following Katherine Murray Lyell's visit, a core group of Huxley's friends met and organised a subscription for him. John Lubbock's bank, Robarts, Lubbock & Co., handled the money raised and it was decided that Darwin should be the one to write and inform Huxley of the gift (letter to John Tyndall, 11 April 1873). Huxley wrote a letter of thanks to Darwin on 24 April 1873 and a copy of that letter was circulated among the subscribers (letter to subscribers to T. H. Huxley's gift, [25 April 1873]).