Healthcare’s snake-on-a-stick device

My series of pieces about the symbology of the Royal Pharmaceutical Society’s heraldic insignia has now reached the shield’s “third quarter”, ie, the bottom left segment. The device here, according to the shield’s heraldic description, is “a Staff erect entwined by a Serpent”.

This snake-on-a-stick device is widely used to represent the treatment of illness by drugs. It has been a medical symbol since the classical Greek era and has been adopted as a logo by many healthcare organisations around the world. The emblem is generally called the staff or rod of Asclepius (or, in Latinised form, Aesculapius). Asclepius was the Greek deity most commonly associated with the medical treatment of illness.

It seems that the serpent and staff were originally separate symbols that became combined during the development of the Asclepian cult. Nobody is now sure of the significance of either element of the device, although that has not stopped numerous supposed experts offering their interpretations. Some have even identified the serpent as the European rat snake, Zamenis longissimus. This is a harmless tree-climbing reptile that is now common only in parts of France and Poland — and in Regent’s Park in a colony founded by truants from London Zoo.  

The rod of Asclepius should not be confused with the caduceus, a staff with a pair of wings and a pair of snakes, which is the emblem of the Greek god Hermes (Mercury to the Romans). One medical body that did famously confuse the two is the US Army medical corps, which adopted the caduceus as its insignia in 1902 at the insistence of a misguided officer. In the wake of this error, a number of other US medical bodies also adopted the wrong emblem.  

Somewhat bizarrely, the snake-on-a-stick symbol actually appears twice on the Society’s full grant of arms, since as well as featuring on the shield it is shown in the hand of Avicenna, one of the shield’s supporters, who points it at the shield. Why the devisers of the arms gave an emblem associated with Greek and Roman mythology to an Arab physician is as much a mystery as the origin of the symbol in the first place.