when the son sleeps with the mother, she kills him with the stroke of a viper.
Edinger cites this alchemical text to show that the viper’s strike enacts the lethal aspect of the lesser coniunctio, where the incestuous union of prima materia and son-substance produces death as a necessary precondition for transformation.
, Anatomy of the Psyche: Alchemical Symbolism in Psychotherapy, 1985thesis