In late 1774, Mesmer was introduced to a new form of treatment with magnets by the Reverend Father Maximillian Hell (1720–1792), a Jesuit priest and the Austrian Astronomer Royal. Several months earlier, in June 1774, Hell had lent a heart-shaped steel magnet (magnetized by repetitive stroking with a lodestone) to a baroness afflicted with intractable abdominal pain.

Four days later, the baroness was restored to health, and Hell ultimately concluded that the magnet had produced curative effects by act-ing on the nervous system. Hell suggested Mesmertry his magnets on Miss Österlin, who had suffered a relapse of hemiplegia in July 1774.

Taking Father Hell’s advice, Mesmer attached Hell’s magnets to Miss Österlin’s feet and another heart-shaped magnet to her chest with dramatic results.

More: https://www.researchgate.net/publication/227277470_Franz_Anton_Mesmer_and_the_Rise_and_Fall_of_Animal_Magnetism_Dramatic_Cures_Controversy_and_Ultimately_a_Triumph_for_the_Scientific_Method

http://mentalfloss.com/article/500464/franz-anton-mesmer-man-who-invented-hypnotism