Medieval and renaissance alchemical manuscripts are often wonderfully illustrated with detailed and complicated images of the individual steps in the process of alchemy.
In many of these images, the process depicted involves the use of a vessel of various shapes and materials. The alchemical process occurs in these vessels, including processes of combination, separation, dissolution, heating, and evaporation.
While the vessel, or vas, itself appears to be a commonly used piece of laboratory equipment, for the alchemist, the vessel was much more than that, as Jung describes:
“Although an instrument, it nevertheless has peculiar connections with the prima materia as well as with the lapis, so it is no mere piece of apparatus. For the alchemists the vessel is something truly marvelous: a vas mirabile”¦.. One naturally thinks of this vessel as a sort of retort or flask; but one soon learns that this is an inadequate conception since the vessel is more a mystical idea, a true symbol like all the central ideas of alchemy”