Radiesthesia

Radiesthesia (French: radiésthesie; radi(o)-aesthesia, perception by the senses) is a proposed method for detecting radiations (or auras) using a practitioner's unconscious nervous responses, interpreted from the movements of a pendulum or other instrument. The term was coined by Abbé Alex Bouly as a way of distinguishing the study and practice from traditional dowsing, which was considered to be less scientific in nature, though the terms are commonly used interchangeably today.

Within the field of radiesthesia, there are multiple distinct practices that apply the same general techniques to different purposes. In medical diagnosis, for example, the detections are intended to determine what areas of a body are healthy or unhealthy, while more conventional applications may involve detecting water, oil, or minerals, either directly or remotely (using a map and pendulum; also known as teleradiesthesia).

Reading

 * Solco W. Tromp, "Psychical Physics: a Scientific Analysis of Dowsing, Radiesthesia and Kindred Diving Phenomena"