All of them dealt with clairvoyance, mediumship, and the afterlife. Joad opposed the spiritualist hypothesis of mediumship. On his return to Britain, Gardner began to investigate spiritualism and mediumship. Enrico Morselli was also interested in mediumship and psychical research. Spiritualists have taken the story as evidence of spirit mediumship in ancient times. The psychical researcher Tony Cornell investigated the mediumship of Alec Harris in 1955. "Trance mediumship" is often seen as a form of mental mediumship. The murlis are derived from mediumship and spirit possession. Magicians have a long history of exposing the fraudulent methods of mediumship. Most physical mediumship is presented in a darkened or dimly lit room. In the Cambridge sittings the results proved disastrous for her mediumship. In the 1920s, Oursler aided Harry Houdini in his crusade against fraudulent mediumship. The genre is famous for its use in rituals for deity mediumship. Some NRMs believe that their scriptures are received through the process of mediumship. Scientific researchers have attempted to ascertain the validity of claims of mediumship.