Auriol: or, The Elixir of Life is a novel by British historical novelist William Harrison Ainsworth. It was first published in 1844 in serial form, under the title Revelations of London. Auriol, written 1844, is slightly unusual in the Ainsworth repertoire as the action is entirely couched as a fantasy, so that the supernatural element (which occurs also, for instance, in his Guy Fawkes and his Windsor Castle) can take comparatively free rein. The story is accordingly a thoroughly gothic romance. It is in effect Ainsworth's contribution to the Faust genre. There is also a distinct connection with The Cabinet of Dr. Caligari, in the kidnapping of girls theme, and in that the story concludes in the atmosphere of the lunatic's confinement (and possible recovery), and the villain of the story is his keeper.