Smell-O-Vision

Smell-O-Vision was a system that released odor during the projection of a film so that the viewer could "smell" what was happening in the movie. The technique was created by Hans Laube and made its only appearance in the 1960 film Scent of Mystery, produced by Mike Todd, Jr., son of film producer Mike Todd. The process injected 30 odors into a movie theater's seats when triggered by the film's soundtrack.