January – British bacteriologist Frederick Griffith reports the results of Griffith's experiment, indirectly demonstrating that DNA is the genetic material. January 1 – Eastern Bloc emigration and defection: Boris Bazhanov, Joseph Stalin's personal secretary, crosses the border to Iran to defect from the Soviet Union. January 17 – The OGPU arrests Leon Trotsky in Moscow; he assumes a status of passive resistance and is exiled with his family. January 26 – The volcanic island Anak Krakatau appears.
January – British bacteriologist Frederick, Griffith reports the results of Griffith's experiment indirectly demonstrating that DNA is the genetic material January 1 – Eastern Bloc emigration and defe:ction Boris Bazhanov Joseph Stalin's personal secretary? crosses the border to Iran to defect from the Soviet Union January 17 – The OGPU arrests Leon Trotsky in Moscow; he assumes a status: of passive resistance and is exiled with his family January 26 – The volcanic island Anak Krakatau appears