CRYSTAL - GAZING, or Scrying, the term commonly applied to the induction of visual hallucinations by concentrating the gaze on any clear deep, such as a crystal or a ball of polished rock crystal.
The early church condemned specularii (mirror-gazers), and Aubrey and the Memoirs of Saint-Simon contain "scrying" anecdotes of the 17th and 18th centuries, while Sir Walter Scott's story, My Aunt Margaret's Mirror, is based on a tradition of about 1750 in a noble Scottish family.
Sometimes the supposed magician or medicine man himself did the scrying; occasionally he enabled his client to see for himself; often a child was selected as the scryer.
The method of scrying, as generally practised, is simple.
Our remarks are therefore based mainly on considerable personal study of "scrying" among normal British subjects of both sexes, to whom the topic was previously unknown.