Caption:
The Second Key of Basil Valentine from the "Twelve Keys of Basil Valentine," an influential alchemical work first published in 1599 by Johann Thölde. It discusses general alchemical principles. Each chapter, or "key," is an allegorical description of one step in the process of creating the philosopher's stone, a legendary alchemical substance capable of turning base metals into gold. Here, a winged man wearing a crown and holding two caducei is approached by two men, one holding a sword with single serpent (i.e. staff of Aesculapius) and the other, a sword with a cock (symbol associated with Aesculapius).