Lawrence Principe - Secrets of Alchemy - Valentine's first three keys

[...] Valentine's "Of the Great Stone" [...] It will suffice to examine only the first three keys in detail. [...] "all impure and contaminated things are unworthy for our work". The theme of purity continues with a comment about how physicians purge illness from sick bodies. The section relating directly to the image advises that

"the king's crown should be pure gold, and a chaste bride should be married to him. Take the ravenous grey wolf that on account of his name is subjected to bellicose Mars, but by birth is a child of Saturn, and that lives in the valleys and mountains of the world and is possessed of great hunger. Throw the kings's body before him that he may have his nourishment from it. And when he has devoured the king, then make a great fire and throw the wolf into it so that he burns up entirely; thus will the king be redeemed. If this is done thrice, then the lion has conquered the wolf, and nothing more to eat will be found in him; thus is our body completed at the start of our work."

The woodcut shows the king, his chaste bride, and the wolf (wearing a collar and looking rather more like a whippet) jumping over the fire. Paternal Saturn (identified by his crutch and scythe) stands nearby. What does it all mean? This riddle is relatively easy. The text clearly describes a purification process. In the context of metallic transmutation, the king is likely "the king of metals", that is gold. This gold (the king's body) is fed to a ravenous wolf who is a child of Saturn. In the standard planetary nomenclature, Saturn is lead; his child would then be something closely related, and useful for purifying gold. The answer is Valentine's favorite substance, antimony ore or stibnite. Stibnite was widely thought to be related to lead, and was used to purify gold. Calling stibnite a ravenous wolf would make sense to anyone who has seen it react with metals. When melted, shtibnite dissolves - "devours" - the metals with breahtaking speed. Corroboration comes from the hint "on account of his name [he] is subjected to bellicose Mars". In German, the name for the mineral stibnite is Spiessglanz, literally "Spear-shine", in reference to its shiny needlelike crystals. A spear, like all weapons, is subject to Mars, the god of war.

This process works very well today. When a piece of impure gold (for example, a 14-karat gold ring or necklace, which contains 58-percent gold and 48-percent copper) is thrown into melted stibnite, it dissolves almost instantly. Metals other than gold are turned into sulfides that float to the surface. A brilliant white alloy of antimony and gold sinks to the bottom of the melt, where it is easily retrieved after the crucible has cooled. When this alloy (that is, the wolf with the king in his stomach) is roasted ("make a great fire and throw the wolf into it"), the antimony evaporates, leaving the purified gold behind. Now that the gold is pure, "nothing more to eat will be found in him"; thus the "lion [king of beasts = king of metals] has conquered the wolf".

The second key discusses the beverages available in the "courts of the powerful", and notes how the "bridgegroom Apollo", before his marriage to the "bride Diana", must be carefully bathed with water "which you must learn to prepare by various manners of distillation". Apollo is god of the Sun, and the Sun is linked to gold, so it is probable that this key starts with the gold purified in the first key. Gold, called king previously, is now called Apollo. Decknamen are not constant, even within a single book - the tricky (and perhaps playful) chrysopoetic writers multiply them unceasingly, sometimes within a single sentence.

The author continues,

"The precious water in which the bridgegroom needs to have his bath must be made most cleverly and carefully from two fighters (understand two contrary things)... It is not useful for the eagle to make his nest alone at the top of the Alps, for his young would freeze from the snow high up the mountain. But when you introduce to the eagle the old dragon who has dwelt long among the rocks, and who creeps in and out of the caves of the earth, and set the two upon a hellish seat, then Pluto will blow strongly and drive out from the cold dragon a flying, fiery spirit whose great heat will burn up the feathers of the eagle and prepare a steam-bath so that the snow on the highest mountains must melt entirely and turn into water, whereby the mineral bath is rightly prepared and can give the king good fortune and health."

[...] The bridgegroom's bath is a liquid prepared by the combat of two fighters, also called eagle and dragon; these animals are shown on the combatant's swords. Fortunately, Valentine mentions an eagle once again elsewhere in the book (probably an example of the dispersion of knowledge). There he equates that eagle with "salmiac", or sal amoniac, a salt today called ammonium chloride. One of ammonium chloride's characteristic properties is that it sublimes easily - that is, upon mild heating the salt vaporizes and then recondenses into a white salt in cooler part of the flask. Given ammonium chloride's ability to sublime, eagle is an appropriate Deckname for it - both the salt and the bird fly through the air. (The modern term "volatilize" derives from the Latin "volare", "to fly"). Accordingly, the "snow on the highest mountains" must refer to the deposit of pure white sal ammoniac that collects at the top of the vessel when the salt sublimes.

Identifying the dragon requires some knowledge of mineralogy. The fact that it lives in caves and around stones suggests saltpeter (potassium nitrate), a salt found naturally as a crystalline deposit on cave walls and in the stone foundations of stables. The remark that the dragon is "cold" further hints at saltpeter, for it tastes cool on the tongue, and it perceptibly lowers the temperature of water as it dissolves. Finally, "a flying fiery spirit" can be driven out of saltpeter by heat - we call it nitric acid - which clinches the identification.

Replication proves the correctness of this interpretation. When ammonium chloride and potassium nitrate are mixed ("introduce to the eagle the old dragon"), placed in a retort in a furnace ("a hellish seat"), and heated strongly (Pluto, god of hell, starts to blow), a vigorous reaction (a fight) does ensue, and a highly corrosive acid distills over. This "mineral bath" is a type of aqua regia, an acid mixture capable of dissolving gold.[...]

The text of the third key describes how water conquers fire, and in the same way

"our fiery Sulfur must be prepared for this art and conquered with water ... so that the king ... is utterly shattered and made invisible. But his visible form must this time appear again."

These allusive directions seem to describe the action of the prepared acid ("water") on the purified gold ("Sulfur"). Namely, the gold is dissolved ("utterly shattered") by the acid into a transparent solution ("made invisible"). Making "his visible form ... appear again" implies that the gold reappears, suggesting that the solution should be evaporated to leave behind a residue, in this case gold chloride. Gold chloride is unstable in the presence of heat, so when its solution is evpaporated, the residue decomposes quickly to produce gold once again - thus, the king's "visible form" reappears.

Valentine continues, "He who would prepare our unburnable Sulfur of all the Sages must take care to seek out our Sulfur in something where it is unburnable, which cannot be done unless the salty sea has swallowed the corpse, and then entirely spat it out once again". The Sulfur of the Sages is a title for the Philosophers' Stone, goal of the twelve keys. To attain it, Valentine implies, one must use more acid (salty sea) to redissolve the gold (the corpse, that is, the residue from evaporating the first solution), and then distill it off again to restore ("spit out") the gold. This direction seems to make no sense chemically; it does not get us anywhere. Nevertheless, it describes a common chymical operation called cohobation, a technique not used by chemists today. In this process, a liquid is distilled off of some substance, and then the same liquid is poured over the residue and distilled off again - often for dozens of times in succession. [...] What could this repetition possibly achieve ?

Valentine then reaches a new crescendo of the bizarre:

"Then raise him up in degree so that he far surpasses all the other stars of heaven in brightness ... this is the rose of our masters, scarlet in color, and the red dragon's blood ... Endow him with the flying power of a bird as much as he needs, thus the rooster will eat the fox, be drowned in water, be made living by fire, and be eaten in return by the fox, so that like and unlike are made alike."

(Gold dissolves in acid, forming gold chloride; when the acid is distilled off, the gold chloride is decomposed by heat into gold and chlorine gas; the resultant gold is redissolved in acid, and so on).

[...] The third key shows the red dragon in the foreground, and that strangely carnivorous rooster both eating a fox and being eaten by him in the background. [...] Roosters had long been linked to the Sun (they crow at sunrise), and the Sun in turn to gold. Rooster would then be the fourth Deckname for "gold", previously encoded as king, Apollo, and Sulfur. The fox is a particular consumer of barnyard fowl (as in "a fox in the henhouse"), and consequently must be a new cover name for the acid that "eats" the gold. So, Valentine's allegory can be deciphered as follows: the gold drinks in the acid (rooster eats fox), is dissolved by it (drowns in water), reappears when heat evaporates the acid (rooster brought back to life by fire), and is then redissolved by fresh acid (fox eats rooster) during cohobation. This interpretation seems plausible - it both fits the text and is chemically possible - but the process still seems like running in place.

[...] To "make the fixed volatile and the volatile fixed" was a guiding axiom for making the Philosophers' Stone, and few substances are more "fixed" (that is, nonvolatile) than gold. [...] Despite being "the most difficult difficulty of the difficulty", in 1895, long after both the alchemical claim to volatilize gold and its ridicule had faded from memory, this very process - allegorically described three hundred years earlier by Basil Valentine - was actually rediscovered independently and chemically explained. Valentine apparently had succeeded in volatilizing gold. Seventy years after him, so had Robert Boyle, who successfully deciphered and followed experimentally at least the first three of Valentine's Twelve Keys during his own quest to prepare the Philosophers' Stone. [...]

Valentine's astonishing success depended on that seemingly useless cohobation. The repeated formation and decomposition of the gold chloride fills the distillation apparatus with chlorine gas. This toxic gas prevents the decomposition of the otherwise highly unstable gold chloride, allowing it to sublime as beautiful ruby-red crystals, or in Valentine's more vivid language, "the rose of our masters ... and the red dragon's blood".