Emily Ogden in Lapham’s Quarterly:
In 1784, America’s soon-to-be second, third, and fourth presidents celebrated the publication of a report debunking the practices of Franz Anton Mesmer, a Vienna-educated physician whose name gives us the word mesmerizing. John Adams, Thomas Jefferson, and James Madisonall rejoiced to know that Mesmer would no longer impose on credulous Parisians with his invisible fluid of animal magnetism, a living or vital counterpart of mineral magnetism. Mesmer said that animal magnetism crackled all around us, though it was especially concentrated in human nerves. He claimed he could cure illnesses by manipulating this invisible fluid in the ailing body. His theory did not seem as implausible in 1784 as it does now; it crossed ancient humoral medicine with the best accounts then available of how electricity and magnetism worked. Mesmer had made a few false starts in Austria, including the time he promoted a theory of “animal gravitation,” before taking Paris by storm in 1778. While he called his practice animal magnetism, his opponents would coin, and his successors would eventually adopt, the term mesmerism.
Mesmer’s patients—most of them female and well-to-do—found him through word-of-mouth and in pamphlets advertising his metaphysical talents. They met in his richly appointed treatment salon, where they gathered around a bucket filled with shards of glass and water that concentrated the life-giving animal-magnetic fluid. Mesmer said all illnesses had the same cause: a blockage in the flow of animal magnetism.
More here.