The Invisible Ray (1936)

Director: Lambert Hillyer
Cast: Bela Lugosi, Beulah Bondi, Boris Karloff, Frances Drake, Frank Lawton, Paul Weigel, Violet Kemble Cooper, Walter Kingsford

Synopsis:

Dr. Janos Rukh discovers a certain type of radium that has almost magical healing properties. But the element has a dangerous side, too, and it has already started affecting Rukh. Consumed by paranoia, he begins to suspect that his wife is having an affair. Wild for revenge, Rukh hatches a deadly plot…using his own poisoned body as a weapon to kill.