The ouroboros became a central emblem of alchemy, where it signified the circular, self-consuming process of the work, dissolution and recoagulation, the unity of matter, the idea that one is all. It is drawn in an early alchemical manuscript associated with Cleopatra the Alchemist with the motto hen to pan across the circle. In the twentieth century Carl Jung treated it as an archetype of psychic wholeness. It also generated one of science's best-known anecdotes: the chemist August Kekule said he arrived at the ring structure of benzene after picturing a snake seizing its own tail, a story he told decades later that made the ancient symbol an emblem of scientific insight. Across all these uses the core idea is constant: a self-renewing whole with neither beginning nor end.
Kekule's own account of the benzene ring, given as an after-dinner reminiscence at a chemists' celebration in Berlin in 1890, describes a half-waking vision of a snake seizing its own tail rather than the ouroboros symbol by name, and historians of science have questioned how literally to take a colourful story told decades after the actual 1865 discovery, without dismissing that some associative insight likely occurred. Jung's use of the ouroboros as an archetype of psychic wholeness drew on the alchemical corpus he spent decades studying, reading the serpent's self-consumption as a picture of the psyche integrating its own unconscious contents rather than as a static symbol of eternity alone, a reading distinct from the more purely cyclical sense the image carried in its Egyptian and Gnostic settings.