Magnetism occupied a large place in the minds of the great thinkers of the sixteenth and seventeenth centuries. There is no doubt that Paracelsus accepted, quite literally, what we embody in figurative expressions with regard to magnetism. To him the attraction of sex was magnetic. People had personal magnetism because they possessed physical powers by which they attracted others. He considered that these powers of attraction were expressions in human beings of the power of the magnet in the physical world, and that the two were literally equivalents. Kepler, one of the deepest thinkers of his time, evidently entertained the idea that the magnet represented the soul of the physical world, and that the planets were held in connection with the sun and their satellites with the planets, by magnetic attraction. We now call it the attraction of gravitation. We understand the force no better than before, but have changed the terms. Descartes theorized much along magnetic lines, and felt that by the use of certain expressions he was adding to knowledge, though he was really only multiplying terms.

Human Magnetism.—How seriously the question of human magnetism was taken will perhaps be best appreciated from one old fallacy. For a long period it was supposed that human beings were so highly magnetic that if a man were exposed in an open boat, in perfectly calm weather, in the open sea, where no currents would disturb him, his face would turn to the north, under the same magnetic influences as caused the needle to point to the north! Many studies of magnetism were made at this time, so that the subject {42} attracted widespread attention. Columbus had made some rather startling observations on his voyage to America with regard to the declination of the magnetic needle, and, during the century following, Norman and Gilbert made interesting studies in the same subject. Father Kircher wrote two books on magnetism and there were a number of others written by university professors. Advantage was taken of this thoroughly scientific interest in magnetism to erect a whole body of pseudo-scientific medicine supposed to be founded on magnetic principles. The same theories were also applied to supposed explanations of various psychological phenomena.

During the sixteenth and seventeenth centuries the application of magnets was a favorite treatment for a great many diseases. Especially were they useful in the treatment of muscular pains and aches and the chronic diseases which so disturbed men's minds. Many of the joint troubles of the aged, the muscular pains and aches that develop from the wrong use of muscles, and the vague internal discomforts which often disturb men so seriously, were cured by the application of magnets. Perkins' success with his tractors shows how much can be accomplished in this way.