Letter from Esther Simpson, Society for the Protection of Science and Learning, to A V Hill, Secretary of the Royal Society Informs Hill of an incident at Cambridge in which a policeman appeared in the Biochemistry laboratory and informed the foreign scientists working there that they were to leave and not return until they had obtained a permit from the AWS Department at Oxford. Describes some of the scientists 'turned out in this way' - a Czech scientist, a Polish assistant. Hopes that Hill might be able to explain to those responsible 'that such measures do interfere seriously with important scientific work and cause pain...to friendly scientists'. 1 September 1943