Caduceus

The caduceus (☤; ; from Latin cādūceus, from Ancient Greek κηρύκειον (kērúkeion) 'herald's wand, staff') is the herald's staff carried by Hermes in Greek mythology and consequently by Hermes Trismegistus in Greco-Egyptian mythology. The same staff was borne by other heralds like Iris, the messenger of Hera. The short staff is entwined by two serpents, sometimes surmounted by wings. In Roman iconography, it was depicted being carried in the left hand of Mercury, the messenger of the gods. The iconography of the caduceus may have roots in Mesopotamia with the Sumerian god Ningishzida, dating back to 4000 BC to 3000 BC. His symbol was a staff with two snakes intertwined around it, perhaps representing two snakes copulating. As a symbol, it represents Hermes (or the Roman Mercury), and by extension trades, occupations, or undertakings associated with the god. In later Antiquity, the caduceus was stylized into the astronomical symbol for planet Mercury. Through its use in astrology, alchemy, and astronomy it has come to denote the planet Mercury and the eponymous planetary metal. It was said that the wand would wake the sleeping and send the wakeful to sleep. If applied to the dying, their death was gentle; if applied to the dead, they returned to life. Extending its association with Mercury and Hermes, the caduceus is also a symbol of commerce and negotiation, areas of reciprocal exchange. This association persisted throughout classical antiquity to the modern era. The caduceus is also a symbol of printing, by association with the eloquence of Mercury. The rod of Asclepius, a similar symbol with only one snake and no wings, is the most common traditional symbol of medicine, but the caduceus is sometimes used by healthcare organizations in the US.