Reg.lat.1200

of the mastery magisterium | the Great Work, or the total process of alchemical transformation. And this same vessel acts as an immutable mother, because within it [the elements] are generated and conceived; they are likewise generated and nourished. For if the vessel of our mastery is not said to be suitable, the entire work is destroyed, nor does our stone lapis noster | "our stone," the evolving substance of the Philosopher's Stone produce the effect of generation, because [the work requires] finding a vessel suitable for generation.

Hence John Saturnus Possibly a reference to Johannes de Rupescissa or another medieval authority writing under a Saturnian pseudonym; Saturn is often associated with the leaden, initial stage of the work. says: Know that it is enough for you to place the stone in our vessel once and close it until the entire mastery is completed. But whatever is more than this is from evil original: "a malo est." This is a paraphrasing of Matthew 5:37 ("anything beyond this comes from the evil one"). In an alchemical context, it warns the practitioner that interfering with the sealed vessel or adding more ingredients after the process has begun will ruin the work., because on account of