The Chemistry of Alchemy Page 11

  But just as we are about to consign della Porta to the clouds from which he operated, he offers “We shall teach thus compendiously to part Gold from Silver.” The parting of silver and gold. The practical procedure that won alchemists the begrudging praise of the miners.

  Not to worry. Della Porta did not disappoint us further because he then offered a secret method for invisible writing and a stone that moves on its own. Ridiculous! Or is it…?

  To the academy of natural magick!

  DEMONSTRATION 7. THE PARTING OF GOLD

  The first demonstration of this chapter is very rewarding—but we're not multiplying gold, we're dividing. We're recreating the gold-parting process central to “Rocky Romance.”

  MINERAL ACIDS

  The parting of gold lauded by Biringuccio and Agricola and recorded by della Porta involves mineral acids. Our original notion was to have you manufacture your own acids the way the early alchemists did, by extracting the quintessence of minerals. However we quickly found these reactions are dangerous and difficult enough to ruin the fun, so we decided not to recommend it. But we managed to produce some mineral acids ourselves, so we will tell you our adventures.

  The acids are called mineral acids because they come from minerals. Straightforward enough. But the manner by which they are extracted is another story. The minerals are heated to extreme temperatures in a retort (the goosenecked device illustrated in the art for part 4 on page 237, second shelf down, third in from the right), and the acids, formed by the reaction of the hot minerals with oxygen and moisture in the air, are collected as condensed vapors emerging from the neck of the retort.

  Who but an alchemist would think to roast a rock to extract its quintessence? When they found the quintessence was powerful enough to dissolve other rocks and etch metal, they thought they really had something. And they did.

  The principal mineral acids are hydrochloric acid, HCl; nitric acid, HNO3; and sulfuric acid, H2SO4; names and formulas that probably stir memories from high school chemistry or physical-science class. We managed to make all three! To a minor extent…

  The first acid we made was sulfuric acid, which was known to alchemists and artisans as oil of vitriol. “Oils” were, in general, liquids, and oil of vitriol was the liquid form (they thought) of vitriol, which, by its modern name, is iron(II) sulfate. Iron(II) sulfate is found in a mineral form, that is, a rock, and to make our oil of vitriol we placed our rock in a retort and heated it to the highest heat we could achieve. After several tries and much patience we were able to collect a few milliliters (less than a teaspoon) of liquid that tested acidic with litmus paper.

  That was our sulfuric acid.

  We then used sulfuric acid to make the second acid, hydrochloric acid, but we did not use our sulfuric acid (we had only a few milliliters). We used a commercial sample of sulfuric acid and allowed it to drip onto a pile of table salt, sodium chloride. We collected the gas that formed by bubbling it through water. This was our hydrochloric acid, which the alchemists called spirit of salt, or spiritus salis.

  The last acid, nitric acid (which they called aqua fortis), we made from sodium nitrate, but the secret for making sodium nitrate will be revealed in a later chapter. Here we'll just say sodium nitrate is a salt similar to sodium chloride (table salt), so we used a similar technique for making nitric acid as we used for hydrochloric acid: we dripped sulfuric acid on sodium nitrate, but instead of producing a gas we produced a liquid mixture that would have needed to be distilled to separate the nitric acid, and we did not do this final step.

  Suffice it to say, our respect for the patience, persistence, and dedication of the alchemist grew from our experience with the mineral acids. Furthermore, given our experience, we decided to recommend a more mundane source of acid for you: aquarium-pH-lowering solution.

  No rocks involved.

  DISPOSAL

  The materials from “Invisible Writing” and “The Stone That Moves on Its Own” can be disposed of in the trash. However, the solutions from “Parting Gold” must be disposed of by an agency licensed to reclaim or dispose of heavy metals. Alternatively, the solutions in sample bottles make a lovely addition to your mantel alchemy collection.

  PARTING GOLD

  For this demonstration you will need a sample of gold alloy, such as the 14-karat-gold wire we recommend for purchase in “Stores and Ores.” Initially we used an old piece of gold jewelry, but we do not recommend this for you because gold jewelry, especially older pieces, can contain lead or nickel as alloying agents. To avoid this problem, we recommend you get your gold sample as gold wire from a jewelry-supply outlet (as described in “Stores and Ores”) and make certain it is lead and nickel free.

  You will also need two beakers, a funnel, filter paper or a coffee filter, a 25-milliliter Erlenmeyer flask, a watch glass, and probably tweezers. For safety you will need surgical gloves, an apron, and (of course) safety glasses.

  Coil your 5-inch sample of 14-karat-gold wire so it is compact and will fit in the bottom of your 25-milliliter Erlenmeyer flask. Using the marking on the flask to measure, cover the gold with about 10 milliliters of aquarium-pH-lowering solution.

  Aquarium-pH-lowering solution is actually a solution of sulfuric acid, a mineral acid, which is why we ask you to get aquarium-pH-lowering solution specifically. Add one-eighth teaspoon of saltpeter (sodium nitrate; see “Stores and Ores”), and swirl the flask gently to mix the salt and acid. By adding sodium nitrate, you have created a mixture of sulfuric and nitric acid, which is sufficient to dissolve everything in the 14-karat-gold alloy except the gold. Put the flask with acid in your cast-iron skillet so the skillet can act as a catch pan for any accidental spills, and cover the flask by balancing a watch glass on the flask's top.

  Heat the gold and acid on a burner at about 40 percent power with the exhaust fan turned on full. The solution will boil after about ten to fifteen minutes, but if you look closely, there are two kinds of bubbles—tiny, continuous bubbles in a stream rising from the metal and larger, collapsing bubbles associated with boiling. The small bubbles indicate the metal is being attacked by the acid, and these are the ones we want to see.

  As the solution volume decreases due to evaporation, keep bringing it back to 10 milliliters by careful addition of pH-lowering solution. After one to two hours of heating, the tiny bubbles should cease, indicating all the dissolvable alloy metals, such as copper and silver, if present, have parted from the gold. The gold itself is too tough to dissolve under this treatment, so you will still see bits of gold wire in the flask.

  At this point the solution is probably a blue color close to the color of the copper-sulfate solution you made for Albert's pigment in demonstration 3. The color comes from the copper in the 14-karat-gold sample. Pure gold, 24-karat gold, is generally too soft to work into jewelry, so copper is added to make gold more workable and to extend the gold. Silver may be added for color and strength, too.

  Stop the heating when the tiny bubbles stop and remove the skillet from the burner so the solution can cool. While it is cooling, assemble your filter apparatus.

  First, find an Erlenmeyer flask large enough to hold your funnel without danger of the filter and flask tipping over. You can use either professional filter paper or the circular bottom cut from a coffee filter, but, in either case, fold the filter in half and then in half again to make a pointy accordion shape that will fit nicely in the funnel (see the illustration with which this demonstration begins).

  When the acid/gold solution is cool, filter it, being careful to trap the remaining gold in the filter. If the gold pieces stick to the side of the flask, you can rinse them out gently with small amounts of water.

  Once the solution is filtered, remove the filter paper carefully, preserving the gold pieces, and set the filter on a paper towel. Save the blue solution that passed through the filter in a sample bottle. Place the gold pieces from the filter back into the 25-milliliter flask, using tweezers if necessary.

  Add 10 millil
iters of the pH-lowering solution to the flask with the gold, one-eighth teaspoon of saltpeter, and, this time, also add one-eighth teaspoon of sodium chloride, or table salt. The sodium chloride turns your solution now into a mixture of sulfuric acid, nitric acid, and hydrochloric acid. The mixture of nitric acid and hydrochloric acid was called aqua regia (royal water) by the alchemist because this mixture of acids was powerful enough to dissolve even gold.

  That was the secret of the alchemists’ gold parting—and now you know it too.

  Swirl the solution to mix, then place the flask in your cast-iron skillet and heat as before. Use the watch glass to cover the flask to slow liquid loss by evaporation, but replenish the pH-lowering solution if the liquid level falls too far below 10 milliliters.

  The solution will slowly turn a rich yellow as the gold dissolves. After an hour or two, all of the gold remnants should have dissolved. When there are no more visible pieces of gold (check with your hand mirror; don't put your face over a boiling beaker!), turn off the heat, remove the skillet from the burner, and allow the solution to cool. Once the solution is cooled sufficiently (at least fifteen minutes), pour the beautiful gold solution into another sample bottle and cap it tightly.

  Set the samples side by side: blue of copper and yellow of gold. A parting of gold.

  Plate 3 in the photo insert shows the blue and yellow solutions collected from one of our gold partings. We have them on the mantel to be admired at will.

  The blue solution will contain any silver from the gold alloy, but there is probably too little to collect. When we dissolved our gold jewelry we were able to precipitate out silver chloride from the solution and show that the precipitate contained silver by putting it in the sun and watching black spots develop. This interesting property of silver salts—that they will darken by forming fine bits of silver metal when exposed to the sun—found use in early photography. However, we did not find enough silver in the gold wire for the darkening of silver salts to be evident. We don't recommend dissolving gold alloys of unknown composition, so just enjoy the pretty blue solution, believe it contains silver, and set it on the mantel or surrender it to the disposal facility as suggested at the beginning of this demonstration.

  Save your gold solution! We will be using it in a future demonstration you don't want to miss! That, and the fact it is beautiful, can only be disposed of by a certified heavy-metal disposal facility, and, well, because it is gold and we all love gold.

  Della Porta loved gold, too, and was fascinated by the parting of gold, but he was fascinated by any natural marvel he found. Any natural magic, such as the next two demonstrations.

  INVISIBLE WRITING

  Della Porta reported the following procedure used by “maids sending…love letters.”15

  Find a lemon, an orange, or an onion and a piece of parchment or paper, whichever you have handy. Write your message in the juice of the lemon, orange, or onion and let the letters dry. The writing should disappear into the paper. Warm the paper gently over a candle, and the writing will reappear. Love letters discovered.

  THE STONE THAT MOVES ON ITS OWN

  Della Porta reported the event as follows:

  That Stones may move alone: The ancients say, that the stones called Prochites and Astroites, laid upon some other plain stone, will move of themselves, if you put Vinegar to them. The way shall be this. Let a plain well-polished, on the outward surfaces, Porphyry Marble stone, lie beneath. Lay upon this the stone Trochites or Astroites, whose outward surfaces, is made smooth also. Then put to them a little Vinegar or juice of Lemons. Presently of themselves will the Trochites, as well as the Astroites, without anything moving them, go to the declining surface. And it is very pleasant to see this.16

  We agree.

  Put on your safety glasses. True, the stones are not going to jump up and give you a black eye—but what if they did? Try explaining that one.

  At any rate, put on your glasses. Find a smooth stone with a rounded surface. Balance a piece of marble chip about the size of a dried bean (as described in “Stores and Ores”) on top of the rounded surface as precariously as possible. Using a dropper, carefully drop vinegar on the marble chip so that some runs down the side and to the bottom of the chip where it meets the surface of the stone. Stand back and wait and you will see the chip move “on its own.”

  Alternatively, if you don't want to go shopping for marble chips, you could place a small seashell, rounded side up, in about one-eighth inch of vinegar in a 250-milliliter beaker. Wait a few moments, and the shell will move on its own. In fact, marble chips and seashells are made up of mostly calcium carbonate, CaCO3. The acid in the vinegar reacts with the carbonate to form carbon dioxide gas (similar to the familiar baking soda/vinegar reaction of science-fair volcanoes), and the growing bubbles deliver the force to move the chip/seashell. Della Porta provided an explanation of what he believed to be the motivating force that involved vinegar insinuating into the solid to force out air. It was wrong, but it showed the care and extent of the alchemists’ observations. They were on the right track.

  Our next champion was on the right track, too. And he also must have been familiar with gold parting and moving stones because he started out in the mines, but then he went for the gold.

  Next, we meet the famous Paracelsus.

  He who wants to study Nature must wander with his feet over its leaves.

  Paracelsus, alchemist, ca. 1530*

  To a student of alchemy, the name Paracelsus is as familiar as Napoleon is to a student of history. And the rest of the world? Suffice it to say, Paracelsus is not corrected by the spellchecker, and few of our heroes stand this test. Volumes have been written on Paracelsus as well as commentaries on his own voluminous writings. Yet, despite all this effort, adoration, paper, and ink, he remains an enigma. J. R. Partington, the great historian of chemistry, relies on F. Hoefer's “description which cannot be improved,” so we are not going to improve it:

  Picture to yourself a man who, in certain moments, gives evidence of a remarkable penetration, and in others raves in the most pitiable way possible; a man who, at one time, devoted to the progress of science, proclaims the absolute authority of experience, and thunders the most violent anathemas against the theories of the ancients; yet at another time, like a lunatic, seems to converse with demons…. Fasting in the morning, drunk in the evening, presenting exactly every idea in the order in which it came to his mind, such is Paracelsus.1

  In our own estimation, we found a genius with a background and persona that did not command respect. We found a sufferer who had socialization issues at the least and perhaps gender confusion as well. He took recourse to self-medication and became addicted to the alcohol that relieved him. Our opening quote paints a picture of a pastoral wanderer, but we found a person escaping from self.

  What then was the basis for his prominence in the history of alchemy? He, like others of his age, saw traditional medicines weren't working. Paracelsus, like others, said alchemy could provide the answers. But if others shared his insights, why was Paracelsus, the drunk, the raving lunatic, chosen the icon for the new medicine? Because Paracelsus, in his madness, was the one who made it work.

  Theophrastus Philippus Aureolus Bombastus von Hohenheim was born in Switzerland around 1492, the time of the Columbian voyages to the New World. He came of age during the rise of humanism and the Protestant Reformation. Taught the rudiments of mining and medicine by his father, “Theophrastus” became “Paracelsus” in his midthirties, as his reputation as a healer grew. A short time before the Christian era, the Roman Celsus compiled an encyclopedic work on medicine; thus, by adopting this name, Paracelsus indicated he was beyond Celsus—a name the spellchecker does not recognize, so Paracelsus may have been right.

  As a young man, Paracelsus worked in the mines, where he probably learned the skills necessary for alchemy, but he did not share the fascination for mining of Biringuccio and Agricola. Of the two possibilities presented by his father, medicine seemed
the more comfortable option, but Paracelsus was not destined for comfort. Genius rarely is.

  Paracelsus probably studied at some Italian universities, though there is no record of his having earned a particular degree. He managed to hire on as a military surgeon (a taxing profession for which there are few applicants), and eventually, wandering closer to home, set up a medical practice in Strasbourg.

  James Froben, a brilliant entrepreneur and thirty years Paracelsus's senior, had teamed with booksellers and illustrators to jump on the publishing boom. By the time Paracelsus moved to Strasbourg, Froben had become quite comfortable and influential. Froben, suffering from a diseased leg, took note of Paracelsus's growing reputation as a healer and asked Paracelsus for his services. Paracelsus cured him. Since others had considered amputation, Froben was grateful for the cure and used his influence to secure a position for Paracelsus as municipal doctor. Paracelsus's star was on the rise.

  The irony of Paracelsus's secret of success was that his cures were no cure at all. The accepted best practice of the day was to treat all illnesses aggressively. Humanism had revived the reverence for Galen and the idea that disease was caused by imbalance in the four bodily humors—yellow bile, black bile, blood, and phlegm. According to Galen cures consisted of adding or subtracting humors with emetics, sweating, purging, or bleeding. Paracelsus instead watched, counseled, and offered opiates for pain. In other words, he did nothing. Paracelsus's genius was to realize that the vigorous treatments of the day could actually weaken the body, and the body, left to its own devices, could many times heal itself. He applied his principle to Froben's friends and found even more success—but if Paracelsus had brilliant instincts when it came to healing, he still had something to learn about presentation.