Photo (about 3½ x 5") showing corona discharge around five fingertips. (Label stuck on back has penciled name of subject.)
The technique known as "Kirlian Photography" was supposedly invented in 1939 by a Russian electrical technician, Semyon Kirlian, but was previously known as corona discharge photography. The process utilizes a high-voltage, high-frequency electrical discharge that is applied across a grounded object. This reveals an air-glow or "aura" effect that can be recorded on photographic film, paper, or plates. New Age mystics believe the corona bands reveal a "life-force" energy that provides information about their health, psychic state, etc.
Actually, experiments reveal it is not the subject's condition but the amount of moisture that determines the Kirlian image's size and shape. Dry fingers were found to produce corona images similar to those yielded by dry, inanimate objects. The color of the corona was also influenced by the amount of moisture present. (See Arleen J. Watkins and William S. Bickel, "The Kirlian Technique: Controlling the Wild Cards, " Skeptical Inquirer 13:2 [winter 1989], pp. 172-184.)