Caduceus

It is a short staff entwined by two serpents, sometimes surmounted by wings. In Roman iconography it was often depicted being carried in the left hand of Mercury, the messenger of the gods, guide of the dead and protector of merchants, shepherds, gamblers, liars, and thieves.
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 and alchemy, it has come to denote the elemental metal of the same name. It is said the wand would wake the sleeping and send the awake to sleep. If applied to the dying their death was gentle, if applied to the dead they returned to life.