In 1848 the Fox sisters, living near Rochester, New York, began modern spiritualism by producing a series of "raps" or "knocks," supposedly from the spirit world, through which communication could be maintained. The public's interest was captured, and soon an overwhelming desire to communicate with departed loved ones led to the devising of other methods of communicating with the spirits.
Spiritualism spread rapidly both in Britain and in the United States, with mediums setting up shop everywhere. Some mediums were obvious charlatans, while others were highly skilled conjurors. Some...