Under Father Hell’s direction, Mesmer attached Hell’s magnets to Francisca Österlin’s feet and another heart-shaped magnet to her chest with dramatic results. She reported feeling streams of a mysterious fluid running through her body and was relieved of her symptoms for several hours:

She soon underwent a burning and piercing pain which climbed from her feet to the crest of the hip bone, where it was united with a similar pain that descended from one side—from the locality of the magnet attached on the chest—and climbed again on the other side to the head, where it ended in the crown. This pain, in passing away, left a burning heat like fire in all the joints. (Mesmer 1775)

Mesmer and Hell then had a public letters battle claiming authorship for the magnetic treatment idea.