In 1784, the Society of Harmony, commissioned by the king of France to study animal magnetism, concluded that it isn't real and called Franz Mesmer (1734-1815), its chief advocate, a mystic and a fanatic. Mesmer, who truly believed in his magnetic therapy, was devastated, and he spent his remaining years living quietly. However, disciples of Mesmer, such as Marquis de Puységur (1751-1825), were unperturbed. Puységur continued to use and refine Mesmer's techniques. Mesmer had conducted therapy sessions in groups in a ritualistic manner. Persons sat in a tub, supposedly filled with magnetic water, and held onto iron rods. The ritual was designed to produce a "crisis" in persons, whereby they might scream, break into a cold sweat, and convulse. Many people reported being cured by Mesmer's therapy. Puységur found that magnetic therapy need not invoke such a crisis to be effective; he could produce equally good results by placing persons in a peaceful, sleep-like trance, which he called artificial somnambulism and which later came to be known as an hypnotic trance. Puységur ultimately discovered much of what is known today about hypnosis: persons are highly suggestible while in a trance; they remember very little afterwards (posthypnotic amnesia); and, upon wakening, they will perform acts suggested to them while they were in the trance (posthypnotic suggestion).