Palm Trees and Potions: On Portuguese Pharmacy Signs
recipes.hypotheses.org
recipes.hypotheses.org
http://www.museudafarmacia.pt/
It would be interesting to get their take on this topic (not to suggest that this author's interpretation is in any way mistaken).
I've always loved the location of that museum by the way - not only beautifully situated facing the water, but also across from a park frequented by sellers of hashish (at least it was when I lived in Lisbon back in 2012). The big iron fence dividing the licit drug museum from the people selling illicit drugs right in front of it has since become my favorite metaphor for the history of drugs.
It which case its origin may be a representation of the treatment for guinea worm.
I've read the caduceus is supposedly an ancient symbol or at least in some way connected to prostitution.
A bit of a faux pas to choose such a symbol!
Thanks for the article.