Heracles rescued Deianeira from rape by the centaur Nessus, using an arrow tipped with the poisonous blood of the hydra. Before his death, Nessus gave Deianeira a love charm composed of his own blood tainted with hydra blood.
Edinger deploys the Hydra’s blood as the alchemical calcinatio agent par excellence, demonstrating that the creature’s poison persists beyond its defeat to generate an inextinguishable, transformative torment.
, Anatomy of the Psyche: Alchemical Symbolism in Psychotherapy, 1985thesis