Undine (alchemy)

Undine (alchemy)

Undines (Latin: Unda — a wave), also called ondines, are elementals, enumerated as the water elementals in works of alchemy by Paracelsus. They also appear in European folklore as fairy-like creatures; the name may be used interchangeably with those of other water spirits. Undines are said to be able to gain a soul by marrying a man and bearing his child. The German folktale of Ondine, a water nymph who curses her unfaithful husband to cease breathing if he should ever fall asleep again, is the basis for "Ondine's Curse," the historical term for congenital central hypoventilation syndrome, in which the afflicted lose autonomic control over breathing, placing them at greatest risk when they are asleep.