Then as now, the Royal Society and its Fellows are among the global scientific elite. They invent and develop technologies we can only dream about. Many worked tirelessly throughout the war on such diverse subjects as maintaining supplies of pharmaceutical drugs previously obtained from German companies, the development of submarines, understanding war wounds and separately malaria. The list is almost endless and includes the little known exploits of the Great War code breakers in 'Room 40'. Dave is a chemist by training. He spent some years in industry before branching out as a military writer. He specialises in the science of the wartime years and the impact on these developments on both world wars. This talk derives from his book, Top Secret. British Boffins in World War I.