The Chemistry of Alchemy Read online

  Once you have a nice, golden sheen back again, remove the skillet from the burner and place it on a heat-resistant surface, such as another, cool, burner. Do not heat it for too long, as the gold color can be ruined with prolonged heating.

  Wait at least fifteen minutes for the crucible and contents to cool. Porcelain can also retain heat surprisingly well.

  Once the crucible has cooled, you can gently pry your “gold nugget” off the bottom. It may require some finesse, but it will eventually come free, and it is definitely worth it. Please see plate 1 in the photo insert for a lovely sample we created. It took some patience and practice, but we were pleased with the final result.

  Why does the tin have this beautiful, shiny, golden appearance? Hot, pure tin reacts with oxygen in the air to form a thin oxide coating. It just so happens that light reflects off this thin layer in a manner that makes the oxide appear gold. The alchemists were thrilled, and so were we.

  Of course anybody familiar with real gold would not be fooled for long, but as we will see in a future chapter, the charlatans didn't need long. But not all alchemists were charlatans, and we believe even the charlatans were hoping in their hearts someday they'd get it right. As you see from your falsified gold, it seemed sooooo close…

  At any rate, congratulations, you are now a falsifier of gold.

  Stay away from stakes.

  ALBERT'S PIGMENT

  Color and dyeing were very important to the alchemists. Alchemists and others of the age saw color as a defining characteristic of a material, which is why they saw the gold coloring of tin and copper as so promising. Different alloys could have different degrees of softness or flexibility, but for the alchemist, they had to be gold colored to qualify as gold. As such, alchemists became experts in the art of creating pigments for paints and dyes.19 William R. Newman, in his book Promethean Ambitions: Alchemy and the Quest to Perfect Nature, commented that painters and artists at the beginning of the fifteenth century were directed to the alchemists for recipes for pigments.20 In addition, the materials, equipment, and techniques of alchemy—distillation, purification, calcination—were necessary to make pigments, so the sale of pigments became a natural sideline for the chronically ill-paying pursuit of alchemy. The following recipes make two common pigments known at the time, malachite and verdigris, two lovely shades of green.21

  You will need the root killer suggested for purchase in “Stores and Ores,” and, oh yes, your safety glasses. Root killer is a pure crystalline, hydrated form of copper sulfate. This blue-colored compound can be converted to the green-colored pigment malachite, named for the mineral malachite found with copper deposits. Albert no doubt encountered malachite on his mineral-collecting expeditions. Verdigris is a patina that forms on weathered copper, a mixture of copper carbonate and other salts, including copper acetate, which is the copper salt of acetic acid, the acid in vinegar.

  To make verdigris, clean a 6-to-8-inch length of copper wire (wash in salt-and-vinegar solution and rinse in water) and then coil it so that it fits in a disposable container, such as a clean, discarded medicine bottle. Pour in a little bit of vinegar and make a hook on one end of the copper coil so it can hang above the vinegar and be exposed to the vinegar vapor. Leave the vinegar undisturbed for a day or two, and a growth of green copper-acetate crystals should form on the coil. You can harvest your verdigris by scraping it off the wire onto a paper towel. You can then put the copper back in the vinegar-containing bottle to grow more verdigris to be used in future demonstrations. Please be sure to keep these materials away from pets or children because they look pretty enough to eat—but you'll have medical bills if that happens.

  To make malachite, dissolve about a teaspoon (5 milliliters) of root killer in about a half cup of water (120 milliliters) in a beaker. It may have to sit overnight to dissolve, or you can warm the beaker gently in your skillet to hasten the process. When it is dissolved, stir in small amounts of baking soda until no more bubbling is observed. The result should be a pale-green mush on the bottom of the container. Drain the excess water from the mush and spread it out to dry on paper towels. Again, the name “root killer” should be your caution to keep this material away from people, animals, and, in this case, even plants.

  When your pigments are dry, you can grind them individually, if needed, and then blend them in a plastic cup with egg yolk, which makes a surprisingly good base for paint. You can also try blending the pigment with egg white, which gives a different texture and tint. Warning: it will stink a bit, so you may want to consider painting something outside. But remember, there's root killer in the paint, so no painting flowerpots, please.

  Color and pigment concerned our next alchemist, too, but where Albert saw green, Geber saw gold.

  …and you shall complete your Work with Joy.

  Geber, Of the Invention of Verity or Perfection, ca. 1300*

  In the fourteenth century, practicing alchemists finally stepped into the spotlight—and were immediately upstaged by the uproar around them. In fourteenth-century western Europe, plague killed a third of the population, peasants rebelled, nobles rampaged, outlaws ravaged, and the pope, bishop of Rome, moved to France.1 The alchemists stoked their fires, and nobody cared.

  To be sure, Pope John XXII called a conference on alchemy in 1317 but concluded by sweeping alchemists under the rug. He decreed anyone caught passing false gold or silver would be fined the same amount in real gold or silver, a fairly lenient sentence, given the times,2 but the pope had bigger fish to fry: the friars. By the fourteenth century the popes lived lives of luxury and magnificence, and some friars took exception to this behavior3 and paid the price. In 1318, twenty-seven radical Franciscan reformers were burned alive at the stake.4

  Other friars took the hint and retreated to sanctuaries of peace and contemplation. One of these was Paul of Taranto, who knew how to stay out of spotlights.

  PAUL OF TARANTO

  Paul of Taranto was a Franciscan friar, possibly a lecturer at a Franciscan school,5 and, if the appellation is correct, born in Taranto, a former Greek colony in southern Italy. There is evidence Paul moved to the Assisi cloister after taking orders, in the village of origin of Saint Francis of Assisi.6 The town still exists, the cloister still exists, and both are amazingly beautiful. The fountained courtyard, white walls, and columns bespeak calm, serenity, and separation from the madness of the world. But serenity means different things to different people, and when Paul turned to contemplation, he contemplated alchemy.

  But as a Franciscan friar, Paul did not receive support from the Church, and, to be an alchemist, one must have material and equipment, so one must have some means—or a patron. Attracting a patron in fourteenth-century western Europe must have been similar to attracting funding today—the important thing is to show what you are able to do. Paul of Taranto showed them what he was able to do by writing a book, a manual of alchemy: Theorica et practica.

  THEORICA ET PRACTICA

  The title used for the book, Theorica et practica (Theory and Practice), was common at the time for this type of manual. There was a Theorica et practica of mathematics, of theology, and of masonry, to name a few. Paul of Taranto's Theorica et practica described alchemical reasoning and supported this reasoning by observations that confirmed he was an actual practitioner of the art.7

  Paul adhered to the mercury/sulfur explanation of the composition of metals, and he accepted the standard method of achieving transmutation: purify the metals, mercury, and other reagents to the purest possible and then rejoin the pure materials into the target metal.8 He offered descriptions of apparatuses, operations, and recipes for silver and gold,9 and, interestingly, methods for assaying gold so one could ascertain, presumably, if a transmutation had been successful. His presentation must have been well received because, according to recent scholarship, Paul of Taranto then wrote another book, similar in tone to Theorica et Practica; yet, the authorship of this book is less certain. The reason? Paul did something different with
this new book: he didn't sign his name.

  The evidence that Paul of Taranto wrote the second book is substantial but can't be confirmed positively because he used a custom prevalent in medieval western Europe called pseudepigraphy, the use of a pseudonym that is also the name of a well-known authority. Paul of Taranto borrowed the name of Jabir, the multifaceted Islamic author, but the Latinized spelling became Geber.

  Pseudepigraphy could get confusing, then as now. Books with the author Aristotle weren't necessarily written by Aristotle. Books by Roger Bacon weren't necessarily Roger Bacon. Even modern attributions are sometimes made incorrectly. But there was a reason for the practice: books written by Aristotle sold better than books by Friar Tuck.

  It makes sense. If anyone found The Secret of the Universe by Albert Einstein today, they would buy it. Of course once they got home and found the style and content clearly were not that of Albert Einstein, they would be annoyed and take it back. But apparently the return policy wasn't as good in the Middle Ages, or people looked at the content, shrugged, and accepted the fake famous name as forgivable hyperbole. At any rate, in medieval western Europe, books by pseudo-authorities were loved by pseudo-philes and enjoyed respectable sales.

  In fact, the co-opted authority for alchemical writings didn't even have to be an alchemist. For instance, a substantial body of alchemical writings was written, supposedly, by Arnald of Villanova,10 but the real Arnald of Villanova said alchemists were “ignorant.”11 Summoned by a Catholic tribunal for equally caustic criticism of the Church, this true Arnald de Villanova wisely volunteered to “temper” his words,12 but the offer was turned down. Fortunately, through timely intervention of his patrons, he was ultimately released, and though censure by an ecclesiastical tribunal may not have advanced his reputation in all circles, for alchemists it put him on the top of the heap.

  The pseudo-Arnald corpus contained much of the same information as Paul of Taranto's work13 but had an added selling point—the content was translated into the vernacular. The practicing alchemists of the fourteenth century—the sweaty, sooty puffers who sat at the fires—could not always read Paul's Latin, if they could read at all. So although the real Arnald wrote that alchemists were “foolish,”14 the imagined mystical Arnald was a much admired adept.

  Similarly Raymond Lull (1232–1315) had a fairly low opinion of alchemists, but that didn't stop booksellers from trading off his name.

  The real Ramon Lull was an evangelist who did not join any order of the Church but who probably worked with and associated with the Franciscans as laity. He became a missionary as a result of visions and did not practice alchemy in any capacity—yet the alchemical body of work credited to him, which began appearing fifty years after his death, influenced alchemists from the Renaissance through the alchemical researches of Isaac Newton in the 1600s. These works also had the advantage that they appeared in vernacular languages.15

  Though we've offered only a few examples here, pseudepigraphy was fairly common, and while selling books was probably a primary incentive, there may have been another motivation for anonymity: fear.

  By the mid-fourteenth century the attitudes of and about the mendicant friars were beginning to change. Their orders originally arose from the desire to return to the fundamental teachings of Christ, and the friars lived lives of poverty, preaching, and service. As such, they were respected by the populace. When the belligerent friars threatened the Church with their righteous indignation,16 the commoners were quietly supportive. But when a few friars felt the tug of worldly comfort and adapted, resentment began to grow.

  The mendicant friars, theoretically, depended on begging for their sustenance. But begging from the impoverished rarely works well, so some decided to do their service for the wealthy. They became attached to households of nobles and knights, serving as chaplains and tutors, presumably still going barefoot while about their household duties but apparently donning sandals when venturing outside. The wealthy liked supporting a friar because it made them feel pious, but the commoners resented the deviations from the friars’ prime directive. The wandering friars became the butt of jokes and ribald tales, and a few suffered physical attacks on their person from indignant citizenry for acting in non-holy ways and in general “not behav[ing] as friars ought.”17 To support their new lifestyles, some friars infringed on the purview of pardoners and sold “drafts on the Treasure of Merit supposed to be stored in Heaven by the Order of St. Francis.”18 Others sold fake relics, and others found a new way to make money: alchemy.

  We know some Dominicans practiced alchemy because there are extant documents condemning the practice.19 In 1323, an ordinance stated anyone learning or practicing alchemy should burn their books, and anyone who did not comply would suffer a “heavy penalty” including (but presumably not limited to) excommunication and imprisonment. Alchemists were denounced by Nicholas Eymeric,20 noted author of guidelines for inquisitors. Derided and physically attacked, in Chaucer's work “The Canon's Yeoman's Tale” (ca. 1370), the alchemist runs away when he realizes his yeoman revealed his questionable occupation.

  Sensing the downturn in sympathy, Paul may have been okay with signing his name to the first book, but by the time he wrote the second book, Paul of Taranto became Geber, King of the Arabs, and Geber wrote Summa perfectionis: The Sum of Perfection.21

  Figure 4.1. The title page of an alchemical work attributed to Geber, printed ca. 1550. (Image courtesy of Roy G. Neville Historical Chemical Library, Chemical Heritage Foundation Collections.)

  THE SUM OF PERFECTION

  The full title of Geber's book has been translated as Of the Sum of Perfection; or, Of the Perfect Magistery, but the translation still requires interpretation. As we understand it (and we're not versed in Latin), Summa could indicate both a summation and a peak, a summit, so we are talking about a compendium of methods by which to reach a goal, or the peak of perfection, which in this case is the creation of gold. So the first part of the title could be rewritten as A Summary of Methods for Making Gold, though we admit Sum of Perfection or Peak of Perfection sounds better. Magistery may have originally meant “method” but gradually came to mean a material. So the second part of the name may mean a perfect material for making gold; in other words, the philosophers’ stone. So we have interpreted the title as A Summary of Methods for Making Gold and the Philosophers’ Stone. And that bit of deciphering is just the title.

  To read and apply the information in the book, one has to be an alchemical initiate—but only in the sense that reading a modern chemistry book requires a chemistry initiate. A modern student of chemistry has to understand modern language and algebra, and a medieval reader of Geber would have to understand Latin and the basic operations and materials of alchemy—not the hidden keys, anagrams, and encryptions that would be used in future alchemical writings. The Summa is a straight-up recipe book and describes in plain, medieval Latin the materials, equipment, and operations of alchemy.

  The book is very systematic. In it, Geber addresses the reader as “Son” and admonishes the hopeful alchemist to study diligently and approach his work with the right attitude: reverence and optimism. The alchemist, Geber says, must be familiar with both theory and practice. Geber then summarizes the current debate on the efficacy of alchemy by listing objections to the basic assumption of alchemy—that metals can be transmuted—then answers these objections with proof by analogy.

  A few words need to be said regarding proof by analogy. In the European Middle Ages, based on classical antecedent, an analogy was considered a sort of proof rather than merely a description. For instance, in Summa Geber cites an objection to the possibility of transmutation as “We see no Oxe transformed into a Goat, nor any one Species transmuted into another…. Therefore, seeing Metals differ in themselves, can you transform one into another…?” Then he answers the objection by “We see a Worm…to be turned to a Flye, which differs from it in Species;…and a Dog strangled, into Wormes.”22

  The weakness of the
proof is apparent—the analogy is based on a fallacy—so we are tempted to dismiss the approach as archaic. But perhaps it is not as distant as we'd like to claim. The modern model of the electronic structure of an atom is based on Schrödinger's “wave” equation, and we are held to our positions by the gravitational “force” for which there is no agent. Analogy is a useful device for attempting a description of the unknown, and Geber and others of his ilk were doing their best.

  Geber then moves on to alchemical practice and lists materials including zinc oxide, antimony, iron pyrite, table salt, alum, borax, saltpeter, arsenic, and, of course, sulfur and mercury. Non-chemists and non-alchemists alike should be impressed by the number of everyday materials they recognize—and how limited a palette the alchemists had. Geber then lists the known metals, seven in all, and names them by their representative astronomical bodies: gold is Sol (sun), silver is Luna (moon), iron is Mars, copper is Venus, tin is Jupiter, lead is Saturn, and mercury is Mercury (a medieval designation that survived to modern usage). He also gives methods for their purification and preparation.

  Geber then describes the operations of alchemy including sublimation, distillation, calcination, solution, and coagulation. Again, pretty familiar stuff for the modern reader—but caution is advised. Words evolve over time. For instance, when Geber said “distillation,” he included the process we would now call filtration.

  Then he moves to the good stuff: the recipes.

  The recipes are for “medicines” (i.e., elixirs) to cure imperfect metals and make them perfect (i.e., gold). He orders the medicines by efficacy, the first-order medicines being the least efficacious, the third order being the most. The medicines of the first order were sort of the Band-Aids of alchemy: they were not a perfect cure, but they helped. In the demonstration that accompanies this chapter, we will be using a medicine of the first order, but it can give quite pleasing results.