Chaim Weizmann Zionist activity, and executed in 1939. His fate became known to his wife and children only in 1955. Maria Weizmann was a doctor who was arrested as part of Stalin's fabricated "Doctors' plot" in 1952 and was sentenced to five years' imprisonment in Siberia. She was released following Stalin's death in 1953, and was permitted to emigrate to Israel along with her husband in 1956. Weizmann was married to Vera Khatzmann. The couple had two sons. The younger one, Flight Lieutenant Michael Oser Weizmann (1916–1942), fought in the Royal Air Force during World War II. While serving as a pilot
Chaim Weizmann fermentation. He used the bacterium Clostridium acetobutylicum (the "Weizmann organism") to produce acetone. Acetone was used in the manufacture of cordite explosive propellants critical to the Allied war effort (see Royal Navy Cordite Factory, Holton Heath). Weizmann transferred the rights to the manufacture of acetone to the Commercial Solvents Corporation in exchange for royalties. First Lord of the Admiralty Winston Churchill became aware of the possible use of Weizmann's discovery in early 1915, and Minister of Munitions David Lloyd George joined Churchill in encouraging Weizmann's development of the process. Pilot plant development of laboratory procedures was completed in 1915 at