Valentine was born in
Higher Broughton,
Salford, 16 February 1912, elder child of Emmanuel Henriques Valentine and his wife Dora Deborah Valentine
née Besso. He was educated at
Manchester Grammar School and then won a scholarship to
St John's College, Cambridge, where he gained a first class degree in
Natural Sciences. His initial research interest was in
plant physiology, leading to his 1937 PhD thesis ; but the focus of his research changed to
taxonomy, the relationships and distribution of flowering plants, and in 1936 he was appointed Curator of the Herbarium at the Botany School of the university. In 1938 he became a
Fellow of St. John's. He was a member of the
Cambridge Scientists' Anti-War Group and was one of those who carried out experiments and, based on their outcome, published in 1937 a critical examination of the
Air Raid Precaution schemes of the British
Home Office. Their book was given a hostile review in
Nature by retired general
Charles Foulkes and Valentine was one of the signatories of a letter in reply. When the
War began he was drafted into the
Ministry of Food to work on the
dehydration of vegetables (cabbage, carrot and potato) intended for consumption by the armed forces. The success in this work was described in 1943 in the British
House of Lords, which also reported on a Dehydration Mission to the British Empire in Africa, a mission in which Valentine took part. At the end of the war he was the editor of a fuller report of the dehydration work. == Durham ==