The Chemistry of Alchemy Read online

  The peacock's tail.

  Once you have your peacock's tail, remove the skillet from the heat because further heating will destroy the colors and blacken the surface again. Put the skillet on a heat-resistant surface and be careful not to touch the beaker or the skillet with your bare hands because they are probably warm enough to brand you for life. While waiting for the beaker to cool, take some pictures because the colors should come through very nicely right now. Plate 2 in the photo insert is a photograph of a sample we produced in our alchemical kitchen.

  Once the beaker is cool (after at least fifteen minutes), turn it over and look at the bottom of the tin/pewter. You should see another peacock's tail and sometimes this oxide on the bottom is even lovelier. Take it to the window and examine it in sunlight, tilting it to various angles.

  Double-check your ventilation because the next step creates some fumes. And make sure you have your safety glasses on. Do not lean over the beaker to see what is going on at the surface. You should be able to look through the side of the beaker. If you like, you can use the mirror recommended in “Stores and Ores” to look at the surface without exposing your face to the fumes.

  Put the skillet with the beaker of tin/pewter back on the stove and warm it to the point of melting again. When it melts, stand downwind and toss a pinch (about the size of a grain of rice) of sal ammoniac (ammonium chloride) on the tin/pewter. The tin/pewter should immediately bead up into a silver ball and there will be steamy-looking clouds coming off and going up your exhaust.

  We have reached the silver stage.

  Wait, and soon the tin/pewter will take on a deep-golden color again.

  The golden stage.

  Voilà; the philosophers’ stone.

  Of course, the more mundane description is that the tin or pewter simply melted and reacted with oxygen from the air to form a multilayer oxide surface that causes light to diffract and form colors much as the surface of a CD or a motor-oil film on a water puddle will break light up into colors. But the alchemists didn't have CDs or motor oil, and for them the colors were the miracle of the philosophers’ stone.

  Turn off your stove, spread the coals out in the hibachi, put your skillet on a heat resistant surface, and take some more pictures while waiting for everything to cool down so it can be put away.

  You'll have to wear work gloves and safety glasses and have the patience of a Rupescissa, but the tin/pewter should eventually peel off the bottom of the beaker once it is completely cool, and you'll have a nice golden-nugget souvenir. If you wish, you could go back with another batch of tin or pewter and stop at the peacock's tail. Again, once it is cool, it should peel off, too, and you'll have another souvenir.

  After a while the peacock's tail will fade, as all philosophers’ stones must, yet alchemy goes on, and next chapter that's just what we'll see: alchemy as solid as a rock.

  They seek…this stone of theirs until…all their substance goes off in smoke…and instead of multiplying their gold and silver they lose what they had invested in labor and expense, and nothing remains to them except the hope of doing it again.

  Biringuccio, metallurgist, ca. 1530*

  Some paint the development of chemistry as a linear progression—alchemy then chemistry. But we see the science of chemistry as having two roots: the art of alchemy and the practical arts. The difference? Maybe this: the practical artisan dealt in the product, and the alchemists dealt in the possible—and the relationship between the two was not always rosy. Yet, the standoff merely simmered until 1450. Then the printing press came on line, and the game changed.

  Before mid-fifteenth century, alchemy tended to be a pursuit of the educated, especially clerics, because they had disposable income and they could read. Laborers were apt to be illiterate, so trade secrets were handed down by word of mouth. But with the advent of the printing press and availability of books in the vernacular instead of Latin, literacy increased. The artisan wanted to sell how-to books, books that made the job of production easier. The alchemists who had neither job nor product wanted to print books so they could attract a patron. With the printing press, the playing field leveled and the artisan and the alchemist both vied for the printer's attention.

  They had to vie for the printer's attention because, in an abrupt turn to the modern, printers suddenly held the reins previously held by Church and regent. The decision of what was copied by the captive labor force in the monasteries depended on the needs of the Church and the universities (controlled by the Church). The printer, on the other hand, was simply a laborer who could not count on the dole of the Church and had a family to feed. Equipment, ink, and paper were expensive. The books had to sell. The new tyrant of erudition became the typesetter, not the pope—sort of. As we will see, the popes and the inquisitors still had input.

  According to the modern scholar William Eamon, not only did the early printers choose which books to print, they also controlled publicity and distribution. Printers could make a new author—or break a new author. Renaissance printer Johannes Petreius of Nuremberg decided to take a chance and publish a book by Nicolaus Copernicus but added a precautionary preface stating Copernicus was only proposing a model that made the calculations of Easter easier. This same printer also gave Girolamo Cardano, one of the European originators of the imaginary number, i, his initial break. Cardano remembered, “[this was] the beginning of my fame.”1 But the printers weren't handing out favors; they found that science sold.

  Around 1530 the genre Kunstbüchlein also called Books of Secrets2 became popular in several countries,3 and popular pricked up the printer's ear. By “secrets” they meant “trade secrets,”4 and these books were essentially recipe books on everything from medicines to cosmetics to metallurgy and other manifestations of western Europe's up-and-coming industrialization. Two especially important works on metallurgy apropos of alchemy are Pirotechnia and De re metallica—though both took care to distance themselves from the art.

  VANNOCCIO BIRINGUCCIO AND PIROTECHNIA (CA. 1540)

  Born in Siena, Italy, in 1480, three decades after the printing of the Gutenberg Bible, Biringuccio took his traditional time of wandering as a youth and lingered at mines and mining operations. He found his fascination. When it came time to return home and settle down, through his political connections to the ruling Petrucci family, he was placed in charge of the local iron mine and forge and, subsequently, the arsenal and mint, two powerful positions in any government. So his political friends were fortunate—but then not so fortunate. The Petrucci ruled ruthlessly with absolute power, and in 1516 there was a popular uprising.5 The family was ousted and, with them Biringuccio, charged with debasement of the coin. Florence is a day's journey from Siena, and on his way out of town, Biringuccio may have passed the road marker where Master Adam of Florence, our hero of the Fractious Friars, was burned at the stake for currency debasement. A practical man, Biringuccio refused to report back to Siena to answer the charges.

  In seven years, with the restoration of the Petrucci family, Biringuccio was back in Siena. But he was tossed out again within three years, and this time they confiscated his property. In another practical decision, he found alternate employment with the Este and Farnese ruling families and forged cannon and munitions for the papal army. His book, Pirotechnia, was not published until he died, but it provided a legacy for his family.

  The book Pirotechnia begins with a description of ores and materials and then gives methods for assaying; smelting; making alloys; casting statues and guns; distilling alcohol; making fireworks and gunpowder; smithing gold, silver, iron, and pewter; and working a mint “honestly and with profit.”6

  Pragmatic Biringuccio knew better than to rely on anything “other than what I have seen with my own eyes.”7 He knew the work depended on the skill of the worker, not occult forces, and he was an artisan, not an experimentalist. His opinion of the adventuresome alchemists? Pretty frigid. In Pirotechnia, he joked about divining rods and went on lengthy rants against alchemists
. “This art…can give us estates and kingdoms, and…heal…sick and…return…old age to youth—…But in spite of this, the fathers and inventors of the art…are all dead.”8 But his derision was not directed solely at the alchemist. Biringuccio also shrugged off the opinions of the ancients, including Aristotle and Albert the Great. He didn't use proof by analogy or authority; he used the proof of his own eyes, and he'd never seen a metal ore in the same location as sulfur ore or mercury ore, so for him the sulfur/mercury idea was wrong. Enough said, but never mind. In general, he had no use for theory. Just the facts.

  But he seemed to have a grudging admiration for the art of alchemy. He assessed,

  these [alchemists], with bridle broken, run a circular track night and day, without ever having rest; and…I do not know whether anyone has ever arrived at the desired goal….

  [Yet alchemy] is surely a fine occupation, since in addition to being very useful to human need and convenience, it gives birth every day to new and splendid effects such as the extraction of…colors, and perfumes and an infinite number compositions of things.9

  Figure 7.1. The use of sheepskins to harvest gold from streams (lower left), as illustrated in De re metallica. Agricola credits the method to the Colchians, inhabitants of Colchis, the traditional land of the Golden Fleece. (Image courtesy of Roy G. Neville Historical Chemical Library, Chemical Heritage Foundation Collections.)

  Biringuccio also gave alchemists credit for the invention of certain acids from minerals, although without approving their means—purify, purify, purify. When he spoke of repeated distillation and sublimation, he said it was a habit “peculiar to the alchemists.” Biringuccio gave backhanded acknowledgement to their efforts when he said brass was “surely…a splendid discovery, for which we must praise the alchemists, although perhaps whoever discovered [brass] was deceived, thinking that he made gold from copper.” Ironically, Biringuccio was wrong, the discovery of brass actually belonged to his intellectual ancestors, the artisans of Alexandria.

  Biringuccio must have encountered alchemy in his travels because he described alchemical equipment he personally examined as “truly…very ingenious, useful, and attractive work, so that I could not refrain from praising alchemy as the cause of so greatly arousing the ingenuity of the craftsman,” though he did not, like our next author, credit the alchemists for the process in this chapter's demonstration: the parting of silver and gold.

  Gold and silver very happily alloy with one another. In fact, gold ore normally contains some silver and vice versa. In order to produce pure gold and silver or control the percentage of each in the final product (and avoid accusations of debasement, which could lead to tall, flammable poles), one must first “part” silver and gold.

  Methods for the parting of silver and gold have existed since antiquity, but until mineral acids were discovered (another subject of the accompanying demonstration), the gold might be recovered but the silver lost. This would not do for the ruling families of Renaissance Italy. They wanted it all. And they got it all—from alchemists—as acknowledged by our next author, Georgius Agricola.

  GEORGIUS AGRICOLA AND DE RE METALLICA (CA. 1550)

  We had decided, for uniformity's sake, to stick with the vernacular names for our heroes whenever we could, though many of them had Latinized names under which they did their scholarly work. In this case, Georg Bauer is so well known by the Latinized “Georgius Agricola” that we made an exception. The source of the familiarity might be traced to his translators and biographers, Herbert Clark Hoover and Lou Henry Hoover, the eventual president and Mrs. Herbert Hoover.10

  Born in Germany in 1494, Agricola came from a working-class family well off enough to send their sons to university, though Agricola started his studies at the age of twenty, about six years later than average. He studied Greek, wrote a Greek grammar, and remained at the university to teach. This effort aligned Agricola with the new humanist movement in western Europe—which meant the study of the ancients in their original languages—not any other meaning one might be tempted to assign to “humanism.” The western Europeans of the Renaissance remained as inhumane as ever.

  However, as a center of Reformation activity, the university became uncomfortable for Agricola, a devoted Roman Catholic, so he left for Leipzig to take up medicine as a new career. He received an endowment that allowed him to study at Bologna and Venice, and when he returned to Germany his route took him through mining districts—and he found his calling. The use of minerals as medicines, the occupational diseases of the miners, and, parenthetically, their equipment and methods captured his attention.

  Back in Germany, Agricola married and found employment as town physician and apothecary but soon moved to a smaller town so his medical practice would not be so demanding. He used his knowledge of mining to make profitable investments and write Kunstbüchlein. He became rich.

  Now Agricola dedicated himself to his great work, De re metallica. But though he'd managed to sidestep the Reformation once before, as a Roman Catholic in a Protestant country, he was impressed into service as a diplomat. When he returned from his diplomatic mission, he began again on his De re metallica, but then as a doctor he found himself embroiled in a battle with the plague. Ultimately he lost one daughter to the plague, saw his work for reconciliation of Protestant and Catholic fail, and died shortly thereafter at the age of fifty-nine. Nonetheless, four months after his death, De re metallica appeared in print. It went through seven editions and was used as a mining reference for over one hundred years.

  A practical man, like Biringuccio, Agricola took a dim view of the alchemists. In one of his critiques, similar to those of Biringuccio, he noted not only do alchemists seem to live no longer than average, but also

  these [alchemists] teach their disciples…to reduce [base metals] to the primary parts and remove whatever is superfluous in them, and…make out of them…gold and silver…. Whether they can do these things or not I cannot decide; but…we do not read of any of them ever having become rich…although…[they] are straining every nerve night and day to [that] end…[therefore] I should say the matter is dubious.11

  However, he does add, “The alchemists have shown us a way of separating silver from gold by which neither of them is lost.”12

  The parting of gold.

  We don't know who discovered the process, or what that person said at the time of the discovery, but there is a Renaissance explicative that was sometimes used on such occasions: Huzzah!

  Perhaps our gold-parting alchemist said, “Huzzah!”

  With this practical process, gold miners and artisans could greatly increase the yield of ores, reclaim precious metals from scrap, and refine low-quality gold into first-rate.

  So alchemists had their pragmatic side, too, and we'll see this side again in our next hero: Giambattista della Porta, author of Natural Magick.

  GIAMBATTISTA DELLA PORTA AND NATURAL MAGICK (CA. 1560)

  Giambattista della Porta (1535–1615)13 was a contemporary and acquaintance of Galileo. Born near Naples, della Porta's family was wealthy enough to allow him quite a bit of liberty for his pursuits, which seemed to cover about everything. He had already assembled, by the age of fifteen, the first of his books on natural magic, which was destined to occupy him the rest of his life. What was natural magic? It was magic, but not diabolical magic, although sometimes there was only a fine line between. A clear-cut example of diabolical magic might be burning a figure in effigy while invoking the devil. An example of natural magic might be the ability to make predictions of when to plant and the likelihood of rain by looking at cloud patterns or dew deposits. Renaissance weather reporters knew what worked, but they didn't know why, so to them, discerning weather patterns was magic. To della Porta, it seems natural magic was whatever scrap of information on a natural process witnessed by someone, or reportedly witnessed by someone, that he could find.

  Della Porta traveled through western Europe seeking out curiosities and kept a collection of oddities in his
house. He set up an academy of like-minded friends, for which the only entrance requirement was to discover something unknown and interesting, which for della Porta could be just about anything. Unfortunately his academy won him the attention of the Inquisition and a summons to Rome. He was released, but only on the condition that he give up his academy and stay away from “dangerous” sciences. Eamon says the Church didn't like the implication that miracles were natural.

  Yet oddities weren't della Porta's only interest. Indeed he came close to rivaling his colleague, Galileo, in optics—but he couldn't stay focused. He kept coming back to his first love, natural magic, and spent his last days looking for the philosophers’ stone and the quintessence of nature.

  So what were these wonderful experiments, this natural magic, that held such sway? We must illustrate with examples, because nothing but examples will do.

  Some of the recipes were monstrous. Della Porta recommended whitening teeth, “which are often blackened by taking mercury,” with acid.14 Some recipes are bizarre: “If you cast wood into the sea,…after a while…certain Worms breed in it, which by little and little become like Ducks, in the head, feet, wings and feathers, and at length grow to be as big as Geese.” Some are practical, “Quinces…will be preserved well if they are laid up in some place that is cold and dry,” and some are inexplicable: “[to] Discover theft…powder [an Eagle stone], and put it into good bread baked upon the embers, and give it to a thief, the thief cannot swallow it. When he has chewed it, but he must either be choked, or discovered for a thief…as Dioscorides says.”

  On alchemy, della Porta said he would not promise “golden mountains” or the philosophers’ stone, nor “that golden Liquor, whereof if any man do drink, it is supposed that it will make him to be immortal.” Della Porta assured his reader, “These things which here you shall find, I myself have seen, and proved by experience,” then he launches into a description on “How to alter and transform Tin, that it may become Silver.”