Paracelsus originated the theory of animal magnetism. The mysterious properties possessed by the loadstone and transferable from that body to iron, were according to Paracelsus an influence drawn directly from the stars and possessed by all animate beings. It was a fluid which he called Magnale. By it he explained the movements of certain plants which follow the course of the sun, and it was on the basis of this hypothesis that he composed his sympathetic ointment and explained the action of talismans. Paracelsus applied the magnet in epilepsy, and also prepared a magisterium magnetis.
Glauber professed to have a secret magnet which would draw only the essence or tincture from iron, leaving the gross body behind. With this he made a tincture of Mars and Venus, thus “robbing the dragon of the golden fleece which it guards.” This is understood to mean that he dissolved iron and copper in aqua fortis. And as Jason restored his aged father to youth again, so would this tincture prove a wonderful restorative. He commenced to test it on one occasion and very soon black curly hair began to grow on his bald head. But he had not enough of the tincture to permit him to carry on the experiment, and though he had a great longing to make some more, he apparently put off doing so until it was too late.
Van Helmont, Fludd, and other physicians of mystic instincts, were among the protagonists of animal magnetism, and physicians administered pulverised magnet in salves, plasters, pills and potions. But in 1660 Dr. Gilbert, of Colchester, noted that, when powdered, the loadstone no longer possessed magnetic properties. Ultimately, therefore, it was understood that the powder of magnet was not capable of producing any other effects than any other ferruginous substance. But the belief in magnets applied to the body was by no means dissipated. The theory was exploited by various practitioners, but notably towards the latter part of the eighteenth century, when the Viennese doctor, F. A. Mesmer, excited such a vogue in Paris that the Court, the Government, the Academy of Sciences, and aristocratic society generally were ranged in pro-and anti-Mesmer sections. Franklin stated that at one time Mesmer was taking more money in fees than all the regular physicians of Paris put together. And yet Mesmer’s explanations of the phenomena attending his performances were only an amplification of the doctrines which Paracelsus had first imagined.