A quackery radio hypnotic crystal device marketed by E Knowles circa 1930.
This has been placed in the section under galvanism but this device has no electrical properties and certainly no therapeutic ones. A sample of the literature which accompanied these and other devices reads:
‘At the outset, get your patient into a state of mental calm either by the use of the Radio Hypnotic Crystal or by such other methods as your knowledge and diagnosis of the case may indicate to you. Then gradually induce profound hypnotic slumber until such time as you feel that your subject has completely relaxed, in which state his mind may be compared to an unexposed photographic plate on which you can project the image you desire. Begin the cure by gently striving to bend his inclination …’
Users are also warned that there is only ONE Radio Hypnotic Crystal but reassured that neither the Radio Hypnotic crystal or Knowles System has any connection with Magic, Spiritualism or Divination.