A tall, striking doctor with an unusually piercing gaze sits opposite his patient, firmly pressing her knees between his own. He stares fixedly into the patient’s eyes, stroking her limbs, and then passing his hands in front of her body in a series of cryptic motions. Is this man a hypnotist or a movie villain? A healer or a charlatan? In the case of Franz Anton Mesmer, the answer to all of the above could be yes.

Mesmer was an 18th century doctor who developed the theory of animal magnetism (more about that later), as well as a related style of treatment that came to be known as mesmerism. His theories were debunked in his time and sound bizarre today, but some credit him with laying the foundation for the practice of modern hypnotism. He is also part of the select group of people in history to have an entire verb—mesmerize—named for him.

Mesmer was born in 1734 in Iznang, Germany to a forest warden and a locksmith’s daughter. After a childhood studying in a monastery and Jesuit schools, he enrolled at the University of Vienna, where he studied law and then medicine, graduating with honors. Influenced by Isaac Newton’s ideas about the role of heavenly bodies on ocean tides, in 1766 he published a doctoral thesis titled De planetarum influxu in corpus humanum (On the Influence of the Planets on the Human Body). But it was not until several years later, when he encountered Jesuit astronomer Maximilian Hell (yes, his real name) and his treatment of patients using magnets to produce artificial “tides” in the body that Mesmer began referring to animal magnetism. While that may sound like some sort of sexy super power, Mesmer’s meaning was a bit more literal.

His theory held that all living beings have a magnetic fluid (akin to electricity—it was not unusual to speak of energy as “fluid” in Mesmer’s time) running through their bodies, and that this fluid could be transferred between bodies and even to inanimate objects. Health was a result of the magnetic fluid being in balance, while illness was the result of blockages. Taking a page from Hell, Mesmer began working with patients by using magnets to move their fluid around and restore their health. But he eventually abandoned the magnets after deciding that an individual with particularly strong magnetism (such as himself, of course) could achieve the same effect by laying hands on or passing his hands over a patient’s body.

Mesmer married wealthy widow Maria Anna von Posch in 1768, cementing his place in elite society and entering a period of high times in Vienna. He entertained socialites—Mozart and Joseph Haydn among them—at his manse, where he also set up a medical practice. His treatment of patients using mesmeric techniques brought great success for a time, but his failed attempt to cure famous blind piano prodigy Maria Theresia von Paradis around 1777 eventually brought trouble. According to some accounts, Paradis was able to see when Mesmer was in the room, but went blind again when he left. When word got out that Mesmer had not cured her as he had claimed (there were also some reports of inappropriate touching), a scandal erupted, and Mesmer fled to Paris in 1778.

Wellcome Library London // CC BY 4.0

Paris initially proved fertile ground for him. The Vienna scandal didn’t seem to damage his credibility much, and there were plenty of rich, ailing, bored aristocrats in need of his services. Before long, Mesmer was inundated with as many as 200 clients a day, making it difficult to treat them individually. Fortunately, the resourceful doctor harnessed his supposed ability to transfer animal magnetism to inanimate objects and built a helpful contraption, which he called the baquet. The apparatus consisted of a large wooden tub filled with iron filings, glass bottles, and water, magnetized by Mesmer himself. Iron rods protruded from the top, which patients would press to the ailing parts of their bodies.

Descriptions of the scene in the baquet salon are pretty strange. The room was richly appointed and dimly lit, the air filled with incense and weird melodies from an instrument called a glass harmonica. The afflicted sat in a circle around the baquet, hands linked, receiving a healing dose of Mesmer vibes. Mesmer, meanwhile, prowled the room outfitted in an aristocratic wizard getup, complete with a lavender robe and a magnetized metal wand. Patients (most often women) were frequently seized by violent convulsions and fits of weeping or laughter, necessitating their removal to a separate crisis room. Mesmer disappeared for long periods of time to attend the women, which led to some raised eyebrows.

Bibliothèque Nationale de France // Public Domain

Eventually rumors and doubts began circulating about Mesmer’s Paris operation as well. In 1784, King Louis XVI—worried because his wife, Marie Antoinette, was among Mesmer’s clientele—ordered a commission to examine his methods. The group (which included chemist Antoine Lavoisier and visiting American diplomat Benjamin Franklin) was actually less concerned with whether Mesmer’s methods worked than with whether he had discovered a new type of physical fluid. After an inquiry into the practices of Mesmer protégé Charles d’Eslon, it was determined that no such fluid existed. Soon afterward, Mesmer left the city. He wandered around Europe, then lived for years as a relative exile in Switzerland before dying in Austria in 1815.

While Mesmer was disparaged in his day, some of his patients did claim to have been cured by him. Moreover, he stumbled on something still relevant in modern psychological practice. For it wasn’t the righting of a fluid imbalance or Mesmer’s superior magnetism that relieved people of their suffering; it was his ability to induce a suggestive mental state through which ailments, often of a psychological nature, could be alleviated. This technique—stripped of the mysticism and pageantry—remains the basis of hypnosis, which, while still controversial, has become recognized as a valid therapeutic technique—no baquets necessary.

Primary image via Hulton Archive/Getty Images