The mediaeval Rosicrucians speak of the Elixir of Life as ‘a fiery water, a watery fire, a current which flows like water’. The alchemical water had the power to dissolve and animate inert matter, to resurrect the dead, and to wash blackness into whiteness. Water was believed to be the soul of all substances.
Mercurius stands at the beginning and end: He is the Prima Materia; as Dragon he devours himself and as Dragon he dies, to rise again as the Lapis Stone. He is the play of colours in the peacock’s tail and the division into four elements. He is the hermaphrodite that was in the beginning, that splits into the classical brother-sister duality and is reunited in the Coniunctio, to appear once again at the end in the radiant form of the Lumen Novum, the Stone. He is metallic yet liquid, matter yet spirit, cold yet fiery, poison and yet healing draught – a symbol uniting all opposites.“
Jung, Psychology and Alchemy