From the remotest periods of human history to the present time, certain peculiar and unusual conditions of mind, sometimes associated with abnormal conditions of body, have been observed, during which unusual conditions, words have unconsciously been spoken, sometimes seemingly meaningless, but sometimes conveying knowledge of events at that moment taking place at a distance, sometimes foretelling future events, and sometimes words of warning, instruction, or command. The Egyptians and Assyrians had their magi, the Greeks and Romans their oracles, the Hebrews their seers and prophets, every great religion its inspired teachers, and every savage nation had, under some name, its seer or medicine-man. Socrates had his dæmon, Joan of Arc her voices and visions, the Highlanders their second sight, Spiritualists their mediums and "controls." Even Sitting Bull had his vision in which he foresaw the approach and destruction of Custer's army. Until a little more than a hundred years ago all persons affected in any of these unusual ways were supposed to be endowed with some sort of supernatural power, or to be under external and supernatural influence, either divine or satanic. About 1773 Mesmer, an educated German physician, philosopher, and mystic, commenced the practice of curing disease by means of magnets passed over the affected parts and over the body of the patient from head to foot. Afterward seeing Gassner, a Swabian priest, curing his patients by command, and applying his hands to the affected parts, he discarded his magnets, concluding that the healing power or influence was not in them, but in himself; and he called that influence animal magnetism. Mesmer also found that a certain proportion of his patients went into a sleep more or less profound under his manipulations, during which somnambulism, or sleep-walking, appeared. But Mesmer's chief personal interest lay in certain theories regarding the nature of the newly-discovered power or agent, and in its therapeutic effects; his theories, however, were not understood nor appreciated by the physicians of his time, and his cures were looked upon by them as being simply quackery. Nevertheless, it was he who first took the whole subject of these abnormal or supranormal conditions out of the domain of the supernatural, and in attempting to show their relation to natural forces he placed them in the domain of nature as proper subjects of rational study and investigation; and for this, at least, Mesmer should be honored. Under Mesmer's pupil, the Marquis de Puysegur, the facts and methods relating to the magnetic sleep and magnetic cures were more carefully observed and more fully published. Then followed Petetin, Husson, and Dupotet, Elliotson in England and Esdaile in India. So from Mesmer in 1773 to Dupotet and Elliotson in 1838 we have the period of the "early mesmerists."