At one time magnets were credited with extraordinary effects upon the human body. Small doses of lodestone, ground to powder and mixed with water, were supposed to prolong life, and Paracelsus, a famous alchemist and physician, born in Switzerland in 1493, believed in the potency of lodestone ointment for wounds made with steel weapons. Baron Reichenbach, 1788–1860, believed that he had discovered the existence of a peculiar physical force closely connected with magnetism, and he gave this force the name Od. It was supposed to exist everywhere, and, like magnetism, to have two poles, positive and negative; the left side of the body being od-positive, and the right side od-negative. Certain individuals, known as “sensitives,” were said to be specially open to its influence. These people stated that they saw strange flickering lights at the poles of magnets, and that they experienced peculiar sensations when a magnet was passed over them. Some of them indeed were unable to sleep on the left side, because the north pole of the Earth, being od-negative, had a bad effect on the od-negative left side. The pretended revelations of these “sensitives” created a great stir at the time, but now nobody believes in the existence of Od.
Professor Tyndall was once invited to a seance, with the object of convincing him of the genuineness of spiritualism. He sat beside a young lady who claimed to have spiritualistic powers, and his record of his conversation with her is amusing. The Reichenbach craze was in full swing at the time, and Tyndall asked if the lady could see any of the weird lights supposed to be visible to “sensitives.”
“Medium.—Oh yes; but I see the light around all bodies.
I.—Even in perfect darkness?
Medium.—Yes; I see luminous atmospheres round all people. The atmosphere which surrounds Mr. R. C. would fill this room with light.
I.—You are aware of the effects ascribed by Baron Reichenbach to magnets?
Medium.—Yes; but a magnet makes me terribly ill.
I.—Am I to understand that, if this room were perfectly dark, you could tell whether it contained a magnet, without being informed of the fact?
Medium.—I should know of its presence on entering the room.
I.—How?