La Folie du docteur Tube is a 1915 short silent experimental film directed by Abel Gance, in which a scientist takes a white, cocaine-like powder which makes him hallucinate. Gance shows the man's hallucinations by using a series of distorting mirrors and ordinary lenses, because no distoring lenses were available at this moment in timedistorting lenses on the camera. A copy of the film is preserved at the Cinémathèque française and has been digitised.