Copy letter from [David Christie Martin], Assistant Secretary of the Royal Society, to Sir Alfred Egerton, Imperial College of Science and Technology, South Kensington, SW7 Martin is sending on a letter from Dr Guha which was addressed to Egerton as Secretary of the Royal Society, but which Martin nevertheless thinks needs Egerton's attention. He has looked up the reference from Guha and 'it is to a high pressure extractor used by W A Bone, A R Pearson and R Quarendon in extraction of coals by benzene under pressure'. 26 April 1949