What Is Sulfur in Alchemy?

Sulfur is the active principle of the tria prima, the principle of combustibility, color, and the soul, and the principle is what makes the alchemical work burn. Sulfur in the alchemical framework is the soul of every substance, the principle that gives matter its activity, its character, and its capacity to combine with other substances. Without sulfur, in the alchemical theory, the metals would be inert, the medicines would be inert, and the laboratory itself would be a colder and less interesting place. Sulfur is, in this respect, the most important of the alchemical principles from the perspective of what the alchemists were trying to do (Principe, The Secrets of Alchemy, 2013, pp. 88-95; Newman, Promethean Ambitions, 2004, pp. 91-105; Pagel, Paracelsus, 1958; Newman & Principe, Alchemy Tried in the Fire, 2002, pp. 30-50). The caveat about the dating remains: the full tria prima including salt is a 16th-century Paracelsian development, and the earlier Jabirian system has mercury and sulfur only.

The principle and the substance

In the alchemical theory, sulfur is not the yellow, combustible substance known in modern chemistry. Alchemical sulfur is a principle, a fundamental constituent of matter that is present in all substances in different proportions. The alchemists identified the principle of sulfur with the qualities of combustibility, color, oiliness, and the soul-like aspect of matter. The principle is the most active of the three, and the activity is what makes sulfur the most interesting of the alchemical principles to work with.

The principle of sulfur is the active element in the alchemical system. It is the principle that gives matter its character, its color, its odor, and its soul. Where the principle of mercury gives matter its fluidity, its volatility, and its spirit-like aspect, the principle of sulfur gives matter its activity, its color, and its soul. The two principles together, with the third principle of salt, constitute all of matter, and the constitution is the Paracelsian theoretical inheritance.

The alchemists used the term “sulfur” because the ordinary substance of sulfur — the yellow, combustible mineral — was the most visible embodiment of the principle. The ordinary sulfur burns with a blue flame and gives off a choking odor. It combines with metals to form sulfides. It is soluble in oil but not in water. The alchemists saw these properties as expressions of the deeper principle that they called sulfur, and the seeing is what made the term useful.

Sulfur in the theory of metallic composition

Sulfur is one of the two principles (along with mercury) that the alchemists believed to be the immediate constituents of the metals, and the role is the most theoretically important. The differences among metals are, in the alchemical theory, differences in the balance and the quality of the sulfur and mercury. Gold is the metal in which the sulfur and mercury are pure and perfectly balanced. Lead is the metal in which they are impure and unbalanced. The theory is the Jabirian inheritance, and the inheritance is the foundation of the alchemical theory of metallic composition.

The Paracelsian tradition extended the theory to include the third principle of salt, and the extension is one of the more theoretically important developments of the early modern alchemical tradition. The metals are made of mercury, sulfur, and salt in different proportions, and the character of each metal is determined by the balance of the three. The alchemist’s work is to adjust the balance of the three principles, purifying the impure, balancing the unbalanced, and producing the perfect metal.

The alchemists developed a sophisticated set of procedures for working with the sulfur of a metal, and the procedures are part of the operational vocabulary of the alchemical laboratory. The procedures included the calcination of the metal to drive off the volatile sulfur, the dissolution of the metal in acid to separate the sulfur from the mercury and the salt, and the recombination of the sulfur with the mercury and the salt to produce a new metal. The procedures are not trivial, and the procedure literature is one of the more useful places to see the alchemical theory in action.

Sulfur in the Paracelsian medical system

The Paracelsian medical system, examined in the cluster on Paracelsus, is built on the tria prima of mercury, sulfur, and salt, and sulfur is the principle of the soul. In the Paracelsian system, sulfur is the principle of the soul, the active, combustible, soul-like aspect of the body. Diseases of the soul are treated with sulfur remedies — preparations that contain the principle of sulfur in a purified and concentrated form.

The most important of the sulfur remedies in the Paracelsian system is sulfur itself, prepared in various forms. The Paracelsian alchemists developed sophisticated procedures for purifying sulfur, including sublimation, distillation, and recombination with other substances. The purified sulfur was used as a treatment for a wide range of diseases, including skin diseases, respiratory diseases, and the diseases of “sulfur imbalance” that the Paracelsians diagnosed (Pagel, 1958).

The Paracelsian physicians also used mineral and plant substances that contain the principle of sulfur in a less obvious form. The yellow and red colored substances, the oily and combustible substances, the aromatic and pungent substances — all of these were considered to contain the principle of sulfur and were used as sulfur remedies. The list is long, and the inclusion criteria are broad. The breadth is part of the Paracelsian theoretical inheritance, and the inheritance is one of the things that distinguishes the Paracelsian system from the more restrictive Galenic tradition.

Sulfur in the spagyric tradition

The spagyric tradition, examined in the cluster on spagyric alchemy, is the practical application of the tria prima theory, and the spagyric sulfur is the most aromatic and the most colored of the three principles. The spagyric alchemists developed a sophisticated set of procedures for separating, purifying, and recombining the three principles in plant and mineral substances.

In the spagyric preparation of plants, the sulfur is the oily, resinous, colored component that is extracted from the plant by alcohol. The sulfur is the “soul” of the plant, the principle that gives the plant its character and its medicinal properties. The spagyric alchemist extracts the sulfur, purifies it by distillation or other means, and recombines it with the purified mercury and salt to produce the spagyric tincture.

The spagyric preparation of sulfur is a delicate operation, and the delicacy is what makes the spagyric sulfur the most demanding of the three to prepare well. The sulfur is sensitive to heat, and the alchemist must use gentle heating and careful timing to avoid damaging the sulfur. The sulfur is also sensitive to air and moisture, and the alchemist must take care to protect the sulfur from contamination during the preparation. The care is part of the spagyric art, and the art is one of the more demanding pieces of the spagyric curriculum.

Sulfur in the alchemical symbolism

Sulfur is richly represented in the alchemical symbolic tradition, and the tradition is one of the most visible features of the alchemical sulfur. The most common symbols:

The triangle resting on a cross, the standard alchemical symbol for sulfur. The triangle represents the element of fire, and the cross represents the elements of earth and the four corners of the material world. The symbol has survived into modern esoteric use, and the survival is part of why readers recognize it.
The red dragon, the symbol of the sulfur at the moment of its full activation. The red dragon represents the active, combustible, dangerous aspect of the sulfur.
The sun in its midday glory, the symbol of the solar sulfur, the perfected sulfur of the philosopher’s stone.
The king in his red robes, the symbol of the rubedo, the final stage of the magnum opus in which the sulfur is brought to its perfect form.

The pillar on alchemical symbols shows the full range of symbols associated with sulfur, and the long-tail page on the color stages examines the rubedo, the stage in which the sulfur reaches its full activation.

Sulfur in modern chemistry and alchemy

The modern chemist knows sulfur as the yellow, combustible, non-metallic element with the atomic number 16, and the modern chemist knows that sulfur is an essential constituent of proteins and of many other biological molecules, and that sulfur compounds are important in the chemistry of living systems. The modern chemistry of sulfur is one of the better-developed parts of the modern chemical tradition.

The modern alchemist knows the modern chemistry of sulfur, and the modern alchemist also works with the older concept of sulfur as a principle, and the two are not in competition. The spagyric alchemist extracts the sulfur from a plant or mineral, purifies it, and recombines it with the mercury and the salt to produce the spagyric preparation. The modern alchemist does not reject the modern chemistry. The modern alchemist integrates the modern chemistry with the older alchemical framework, and the integration is part of the spagyric inheritance.

The alchemical concept of sulfur is a useful complement to the modern chemical concept, and the complementarity is one of the things the modern practitioner can work with. The modern chemical concept of sulfur is precise and well-defined. The alchemical concept is broader and more symbolic. The two concepts are not incompatible. They are two ways of understanding the same element, and the modern alchemist who works with both has a richer understanding than the modern chemist who works with only one. The richer understanding is part of what the modern spagyric revival is trying to recover.

The alchemical legacy of sulfur is also visible in the modern chemical industry, and the visibility is one of the more useful pieces of the alchemical inheritance. Sulfuric acid, the most important industrial chemical of the modern era, is the descendant of the alchemical “philosophical vinegar” and the “oil of vitriol” that the alchemists prepared by the distillation of green vitriol (iron sulfate). The alchemical discovery of sulfuric acid, attributed to Jabir ibn Hayyan and developed by the Latin and Paracelsian alchemists, is one of the foundational discoveries of the modern chemical industry (Newman, 2004, pp. 100-105). The alchemists were wrong about the philosopher’s stone. The alchemists were right about sulfuric acid, and the rightness is the most useful thing the modern reader can take from the alchemical sulfur.