"Sir William was a member of the Society for Psychical Research from its founding in 1883 and served as president of the society from 1896 to 1899. During his investigations, Crookes discovered that a very successful spirit medium, Mary Rosina Showers, was a fraud, but said nothing and reported nothing about his discovery. He and spirit medium Daniel Dunglas Home were on a very close personal basis, and his endorsement of Home's powers has always been a strong point made by the spiritualists to support their claims about Home. However, Crookes has been shown to be a dupe of such other mediums as Florence Cook and others exposed or confessed as fakes, so his validation of Home is highly suspect."