Putrefactio is ‘rotting,’ the decomposition that breaks down dead organic bodies… witnessing the putrefaction of a dead body, especially a human corpse, which was not an unusual experience in the Middle Ages, would have a powerful psychological impact.
Edinger establishes putrefactio as the psychological projection of witnessed physical decomposition into alchemical process, distinguishing it from purely chemical operations and grounding it in embodied human experience.
, Anatomy of the Psyche: Alchemical Symbolism in Psychotherapy, 1985thesis