Slithering their way through the iconography of pharmaceutical history, snakes appear, often wrapped around a staff, wherever you find apothecaries. Asclepius, the Greek god of medicine, carried a rod with a single snake, which became a medical symbol from the fifth century BCE.
The messenger of the gods, Hermes (the Roman god Mercury), acquired an extra snake on his staff, known as a caduceus. It’s perhaps not a coincidence, then, that the element mercury was a major chemical agent in the history of medicine and alchemy. For example, the evaporated vapour of mercury combined with snake venom was injected through the centre of the scalp as an antidote to snake bite and epilepsy. Both Hermes, the god of commerce, and Mercury, the god of trade, are a good fit for retail pharmacy.
The symmetrical proportions of the caduceus lend themselves to design. It was first used as a printer’s mark (colophon) by a 15th-century book publisher, and its association with medicine was revived in the early 19th century when a medical publisher adopted it. In France, snakes might also be found entwined around palm trees on 19th-century pharmaceutical labels. Perhaps this is a reminder of the exotic origins of many drugs?