The Seventh Key

The story

A robed woman holds a balance in one hand and a raised sword in the other, standing behind a cylinder labeled "Sigillum Hermetis," the Seal of Hermes. Below her, a circle divided into a square and triangle reads "Sal philosophorum" and "Aqua," ringed by the four seasons, Hiems, Ver, Aestas, Autumnus. Contemporaries took the scale and sword as measure and judgment, the correct proportion of ingredients and the cutting-off of the vessel from outside air, both held necessary for the Work to proceed through its stages, here mapped onto a full cycle of seasons to suggest a slow, months-long heating. The sealed cylinder behind her is the detail to notice, a reminder that practitioners believed the whole transformation had to occur undisturbed inside hermetically closed glass. Its tidy geometric diagram made this plate one of the more frequently excerpted images from the series on its own.