Caduceus as a symbol of medicine worth noting that hospital stewards were not physicians; they played a supporting role preparing drugs for surgeons, supervising nurses and cooks, maintaining accounting and medical records, and in emergencies sometimes performed minor surgery or provided prescriptions. Later, in 1871, the Surgeon General designated the caduceus as the seal of the Marine Hospital Service (destined to become the U.S. Public Health Service in 1912). Gershen states that the change was for aesthetic reasons, whereas Friedlander states the caduceus was adopted by the Marine Hospital Service "because of its relationship with merchant seamen and the maritime industry". The caduceus was formally adopted
Caduceus oldest known imagery of the caduceus have their roots in a Mesopotamian origin with the Sumerian god Ningishzida whose symbol, a staff with two snakes intertwined around it, dates back to 4000 B.C. to 3000 B.C. As a symbolic object, it represents Hermes (or the Roman Mercury), and by extension trades, occupations, or undertakings associated with the god. In later Antiquity, the caduceus provided the basis for the astrological symbol representing the planet Mercury. Thus, through its use in astrology, alchemy, and astronomy it has come to denote the planet and elemental metal of the same name. It is said