1 March: the Bank of Italy was nationalized.
29 April: the first device capable of photographing various kinds of sounds—human speech, a heartbeat—was created at the Leningrad Experimental Electrotechnical Laboratory.
Fox begins releasing newsreels with sound. The sound is recorded directly onto the film.
13 May: Germany experienced the collapse of its financial and economic market (“Black Friday”).
May: the United Kingdom severed trade and diplomatic relations with the USSR.
8 August: France announced the creation of a vaccine against canine distemper.
W. Heitler and F. London develop the quantum theory of valency.
Transatlantic telephone service begins operating.