Ouroboros (or Uroboros)

Ancient Greek alchemical symbol of a serpent eating his tail. The mystical work The Chrysopoeia of Kleopatra has a drawing of the Serpent Ouroboros eating his tail, with the text "One is All." Another emblem illustrates the symbols of gold, silver, and mercury enclosed in two concentric circles with the text "One is the serpent which has its poison according to two compositions" and "One is All and through it is All and by it is All and if you have not All, All is Nothing." The symbol of Ouroboros has also been interpreted as the unity of sacrificer and sacrificed, relating to the symbolism of the mystical life.

The symbol dates back to Mesolithic (Azilian) culture and appeared in the symbolism of many races. The Gnostic text Pistis Sophia, describes the disc of the sun as a great dragon with his tail in his mouth. The fourth-century writer Horopollon stated the Egyptians represented the universe as a serpent devouring its own tail, a symbol of eternity and immortality, an image also found on Gnostic gems.

In alchemy, the tail-eating dragon represented the guardian of mystical treasure, symbolized by the sun. Alchemy was to destroy or dissolve this guardian as a stage towards knowledge of this treasure.

Possibly the familiar Chinese Yin-Yang symbol is related to the tail-devouring serpent—here the masculine-feminine principles throughout nature are held in balance.

Sources:

Eddison, E. R. The Worm Ouroboros. New York: E. P. Dutton,1952.

ouroboros, uroboros. Symbol of a snake in circular form, eating its tail (or with its tail in its mouth), suggesting an eternal recurring process, or immortality, and therefore often found on cemetery gates, funerary monuments, etc.