Knowles Radio Hypnotic Crystal
The Knowles Radio Hypnotic Crystal is a glass bulb containing a quantity of sand, attached to a handle or fixed inside an aluminum holder, intended for use in hypnotic therapy as an attention focus, and, specifically, "the production of Fascination, Healing, self treatment by auto-suggestion, the cure of bad habits, treatment at a distance, anesthesia, physiognomy, phrenology, graphology, and cheiromancy." It was originally marketed by Elmer Ellsworth Knowles (a.k.a. Elmer S. Prather) and his National Institute of Sciences as a training tool to be used in accompaniment with his courses in hypnotism, magnetic healing, and like studies.
- Radio Hypnotic Crystal, buxtonmuseumandartgallery.wordpress.com, https://buxtonmuseumandartgallery.wordpress.com/2014/11/21/curiosity-of-the-month-4/ — Buxton Museum and Art Gallery collection, an older model with wooden handle
- Radio Hypnotic Crystal Device, phisick.com, http://phisick.com/item/radio-hypnotic-crystal-device-2/ — a later model, aluminum holder
- Knowles, Elmer E. (1926). The Basic Principles of Suggestion, Hypnotism, Telepathy, Personal Magnetism, Character Building and the Development of the Dormant Faculties. Brussels, Belgium: Psychology Foundation. p. 7. http://www.iapsop.com/archive/materials/wing_lessons/1926__knowles___basic_principles_branch_one.pdf. Retrieved 2016-04-26. "The Radio-Hypnotic Crystal is a most scientific device to enable a person to focus his or her thoughts upon the subject in hand to the exclusion of all extraneous ideas. It is therefore of potent aid in facilitating concentration and assists in overcoming that aberration of mind which is the consequence of so many failures. It is admittedly invaluable in producing that state of passiveness and equanimity in the mind of the subject, which is so necessary in the preliminary stages of any hypnotic experiment. Furthermore, the use of the Crystal has the advantage of giving the student something tangible to work on, something that is equally beneficial to both operator and subject in inducing the proper state of mental composure."
- "REVIEWS: Personal Influence and Healing", The Occult Review (London: William Rider & Son, Ltd.) 16 (1): 57, July 1912, https://babel.hathitrust.org/cgi/pt?id=hvd.32044105235014;view=1up;seq=71