Knowles Radio Hypnotic Crystal



The Knowles Radio Hypnotic Crystal is a glass bulb containing a quantity of sand, attached to an aluminum or brass handle, intended for use in hypnotic therapy as an attention focus. It was originally marketed by Elmer Ellsworth Knowles (a.k.a. Elmer S. Prather) and his National Institute of Science as a training tool to be used in accompaniment with his courses in hypnotism, magnetic healing, and like studies.