Elementals
The elementals are spirits associated with the four classical elements, codified by Paracelsus (Swiss alchemist, 1493-1541): gnomes (earth), undines/nymphs (water), sylphs (air), salamanders (fire). Modern occult tradition (Helena Blavatsky, Rudolf Steiner) developed the concept.
Elementals in folklore
Paracelsus codified existing folkloric beings. Elves, fairies, dwarves of Celtic and Germanic folklore are related figures. Universal concept of "spirits of the place".