Dr. Landis has classified the Korean dæmons as follows:—

Spirits high in rank

Spirits of the House

Various kinds of Spirits

The belief in the efficacy of the performances of the mu-tang is enormous. In sickness the very poor half starve themselves and pawn their clothing to pay for her exorcisms. Her power has been riveted upon the country for hundreds, if not thousands, of years. The order is said to date back 4,000 years, to have been called in China, where it was under official regulations, mu-ham. Five hundred years ago the founder of the present dynasty prohibited mu-tang from living within the walls of Seoul—hence their houses and temples are found outside the city walls.

Women are not mu-tang by birth, but of late years it has become customary for the girl children of a sorceress to go out with her and learn her arts, which is tending to give the profession a hereditary aspect. It is now recruited partly in this fashion, partly from among hysterical girls, and partly for a livelihood, but outside of these sources, a dæmon may take possession of any woman, wife, maid, or widow, rich or poor, plebeian or patrician, and compel her to serve him. At the beginning of the possession she becomes either slightly or seriously ill, and her illness may last four weeks or three years, during which time she dreams of a dragon, a rainbow, peach trees in blossom, or of a man in armor who is suddenly metamorphosed into an animal. Under the influence of these dreams she becomes like an insane person, and when awake sees many curious things, and before long speaks as an oracle of the spirits.

She then informs her family that messengers from Heaven, Earth, and the Lightning have informed her that if she is not allowed to practise exorcism, they or their domestic animals will die. Should they insist on secluding her, her illness shortly terminates fatally. If a daughter of a noble family becomes possessed, they probably make away with her, in the idea that if madness takes this turn, the disgrace would be indelible.