ANIMAL MAGNETISM, or the art of curing diseases by the magnet, was invented by a German philosopher, named Father Hehl, of Vienna, who first applied it to medicine: but the noted Mesmer, a physician of the same city, by adopting his principles, and afterwards carrying them to a greater extent, has been generally considered the author of this splendid, but fanciful system. The principles of that delusive art, are described by him in the following manner:—Animal magnetism is an universal fluid, constituting an absolute plenum in nature, and the medium of all mutual influence, between terrestrial, animal, and celestial bodies. It is a most subtle fluid, capable of flux and re-flux, and of receiving, propagating, and continuing all kinds of motion. The human body has poles, and other properties, analogous to the magnet, and is subjected to its influence, by means of the nerves. The action and virtue of animal magnetism may be transferred from one body to another, whether animate or inanimate. It operates at a great distance, without the intervention of any substance; is increased and reflected by mirrors; communicated, propagated, and augmented by sound; and may be accumulated, concentrated, and transported. By means of this fluid, some nervous disorders are cured immediately, and others mediately: its virtues, in short, extend to the universal benefit and preservation of mankind.
From this extraordinary theory, Mesmer fabricated a paper, in which he asserted that all diseases arise from one common source; that they may be removed by one mode of cure; and that this cure consists in the application of animal magnetism. The folly and credulity of the times soon gained partizans to this new and plausible theory: it became at length so popular and fashionable in France, that the jealousy of the faculty was awakened, and an application was made to government. A committee, consisting of physicians and members of the Royal Academy of Sciences, of which the late illustrious Franklin was a principal member, was immediately appointed, to inquire into its merits, and to ascertain its effects. The consequence of this examination was such as might have been anticipated by every rational mind. The spell was quickly broken, and the whole disclosed to be an artful imposition on the weakness and credulity of mankind. It is now almost universally exploded, and treated with merited ridicule and contempt. The practice, however, and subsequent detection of this wild, and visionary doctrine, have not been altogether useless; since to the philosopher, it has added one more to the numerous catalogue of the errors and illusions of the human understanding; and affords a memorable instance of the power of imagination.—See Electricity and Magnetism.