Leah Price:

Remembered today as an escape artist who was one of the first Hollywood stuntmen, Houdini was equally well known during his lifetime for his campaign against spiritualism. Houdini’s repertoire of magic tricks placed him in an ideal position to spot fraud: the ectoplasm often seen to extrude from mediums’ mouths, for example, bore a suspicious resemblance to the act in which he swallowed a needle and thread and showed spectators his empty mouth, only to pull threaded needles out from between his teeth a moment later. Conan Doyle returned the compliment, charging Houdini with surreptitiously drawing on psychic powers. Since there was no natural way for a straitjacketed man to escape from a locked trunk, the only possible explanation was that he possessed an uncanny ability to turn bones into ectoplasm at will.