MS SPR Museum/Thumbprints
By kind permission of the Society for Psychical Research

Mina Crandon, the wife of an American physician and socialite, first came to prominence as a medium in Boston, Massachusetts, in 1923. Her séances were notable for the wide range of phenomena produced, including an ectoplasmic hand-like form. In 1926 she produced a number of thumbprints imprinted in dental wax, supposedly from her spirit guide, her dead brother Walter. The prints on display were made during a séance in London in 1929. It was later discovered that the prints were those of her dentist.