Vitriol (Green Lion)

The sign 🜖 (U+1F716) is a circle closed on a cross, a vertical stem through the center and a bar meeting it inside the ring. It depicts no lion; it is a salt-cross held in a round vessel. In the Alchemical Symbols block the ring is unbroken, the upright centered, and the arms end at the circumference. Pens vary that scheme. Newton’s notebooks may drop the stem or add a second tick so the mark is not common salt; other hands tilt the bar. Scribal ink often leaves the lower stem open, which separates the mark from a fully closed solar wheel. Gessmann’s 1899 plates keep Vitriolum apart from the salt cross, the solar disc-and-cross, a hasty Venus, and the V–O monograms of oleum vitrioli. Caption, the epithets viride and caeruleum, or the acrostic V.I.T.R.I.O.L. decides the sign.

In the workshop vitriol was a weighed mineral salt, not a metaphor. Green vitriol, melanterite, is hydrated iron(II) sulfate; blue vitriol, chalcanthite, is hydrated copper(II) sulfate; white vitriol is the zinc salt. Workers took them from weathered pyrite and from copperas pans in which iron liquor shot green crystals. The salt is glassy, astringent, and efflorescent, paling as water leaves it. Strong heat drives off water, then sour fumes, and leaves red or yellow colcothar, iron oxide, the assayer’s caput mortuum. Distillation in luted glass retorts and cucurbits, bedded in sand, yielded a sharp phlegm and, under harder fire, the heavy oil of vitriol, later named sulfuric acid. That oil attacks metals and chars organic matter, so refiners used it in parting. Crystal color and the red calx showed which metal had supplied the salt.

Planetary assignment follows the metals that bear the salt. Blue vitriol belongs to Venus as a salt of copper; green vitriol belongs to Mars as a salt of iron. Lists therefore set Vitriolum under both planets, or under Mars when the Green Lion is meant. Aristotelian theory treats the crystals as earth locking a watery, fiery spirit: cold and dry to the touch, yet hiding a sharp humidity that fire releases. Paracelsian writers rank oil of vitriol among the mineral acids that open metals, a corrosive arcanum rather than a kitchen salt. The polarity is deliberate. The Green Lion is youthful and devouring; it swallows the Sun in emblem books and is itself a product of martial calcination. The acrostic Visita Interiora Terrae Rectificando Invenies Occultum Lapidem turns the name into a descent into matter. Vitriol is thus both outward mineral and cipher of inward rectification.

Greco-Egyptian technical papyri and the later Zosimos tradition already know sulfate liquors and the staining salts of copper and iron, though they do not yet fix the Latin name vitriolum. Arabic mineralogy, transmitted through the De aluminibus et salibus literature, taught Latin readers to distinguish vitriols by color and to distill a sharp water from them. Medieval assaying books then treat copperas as a commercial reagent for parting and for ink. Paracelsus and his editors place oleum vitrioli among the chemical preparations of the Archidoxis and related recipes, stressing its power to open bodies. Seventeenth-century emblem books give the substance a public face: Maier’s Atalanta fugiens (1618) stages dissolution beside the vitriol acrostic familiar from Basil Valentine’s circle. Manuscript symbol lists copied by Newton record the same sign among salts. Gessmann’s nineteenth-century corpus gathers those marks without collapsing every Green Lion into one sulfate.

Within the Magnum Opus, vitriol is an agent of Solutio and a feeder of Nigredo. The oil or the acidic liquor of the green salt opens metals, especially copper and iron, and carries them into solution, the necessary unbinding before any recomposition. Emblematic sequences show the Green Lion consuming the Sun: the solar metal disappears into a dark, often green or black liquor, and the work enters putrefaction. Operators knew that stage by lost luster, heat of mixture, and an inky residue. Calcination to colcothar left a fixed red earth that could be imbibed with its own spirit, solve et coagula on one mineral. The acrostic orders a descent into the retort’s earth, rectification of what rises, and a search for the stone in the caput mortuum. Vitriol therefore begins the work by corruption and solution, not by a final fixation.

Eighteenth-century nomenclature stripped vitriol of its planetary titles. Lavoisier’s circle identified the oil of vitriol as sulfuric acid and the green and blue salts as sulfates of iron and copper, while the old names oil of vitriol, copperas, and blue vitriol survived in trade. Berzelius and his successors wrote FeSO₄ and CuSO₄, and later formulas marked the heptahydrate FeSO₄·7H₂O. Industrial sulfuric acid ceased to depend on the distillation of iron sulfate once sulfur-burning and contact processes supplied the acid. The symbol, however, remained a historical character. The Alchemical Symbols block, added in Unicode 6.0 (U+1F700–U+1F77F), assigns U+1F716 to VITRIOL, fixing 🜖 for encoding of manuscripts and emblem books. Lawrence Principe’s reading of early modern chymistry keeps the laboratory salt and the Green Lion in tension: green vitriol explains many images, yet not every leonine emblem reduces to FeSO₄.