An elemental is a mythic supernatural being that is described in occult and alchemical works from around the time of the European Renaissance, and particularly elaborated in the 16th century works of Paracelsus. According to Paracelsus and his subsequent followers, there are four categories of elementals, which are gnomes, undines, sylphs, and salamanders. These correspond to the four Empedoclean elements of antiquity: earth, water, air, and fire, respectively. Terms employed for beings associated with alchemical elements vary by source and gloss.