Franz Anton Mesmer (/ˈmɛzmər/; German: [ˈmɛsmɐ]; May 23, 1734 – March 5, 1815) was a German physician with an interest in astronomy, who theorised that there was a natural energetic transference that occurred between all animated and inanimate objects that he called animal magnetism, sometimes later referred to as mesmerism. The theory attracted a wide following between about 1780 and 1850, and continued to have some influence until the end of the century.