English: “Sexta Figura” (Figure Six), engraved by Matthaeus Merian (1593–1650). Figure 6 from Lambsprinck's De Lapide Philosophico [On the Philosophers' Stone] as published in the Musaeum hermeticum, reformatum et amplificatum. Francofurti : Apud Hermannum à Sande, 1678. In Latin.

Hoc vere est magnum miraculum & cita fraus / In venenoso Dracone summam medicinam inesse.

SEXTA FIGURA.

Mercurius recte & chymice præcipitatus vel sublimatus, in sua propria Aqua resolutus & rursum coagulatus.

That is to say, "Mercury rightly precipitated or sublimated in its own water, dissolved and again coagulated."

A serpent or dragon bites its tail, symbolizing mercury. The ouroborous is one of the oldest alchemical symbols. Allegorical descriptions that required decoding by the practitioner had always been part of alchemical communication. Medieval alchemy in the West added visual imagery to that long tradition.