Letter from Grey Walter, Burden Neurological Institute, Stapleton, Bristol, to Henry Barcroft, Physiological Laboratory, Queen's University, London Notes that 'the people at the meeting could not give any very clear account of low oxygen tension EEG's' but thinks that the 'secret work' will soon be published - sends a memo from Squadron Leader Kerr which he thinks may still be 'semi-secret'. 12 July 1947