A special troop was formed for gas warfare (Pioneer Regiments 35 and 36) under the command of Otto Peterson, with Haber and Friedrich Kerschbaum as advisors. Haber actively recruited physicists, chemists, and other scientists to be transferred to the unit. Future Nobel laureates James Franck, Gustav Hertz, and Otto Hahn served as gas troops in Haber's unit. In 1914 and 1915, before the Second Battle of Ypres, Haber's unit investigated reports that the French had deployed Turpenite, a supposed chemical weapon, against German soldiers.