Alchemy may seem like a strange subject to cover in a course on the history of science. Like astrology, alchemy has, since the eighteenth century, been relegated to the category of a pseudo-science. In our popular culture, alchemy and astrology are now strongly associated with magic and the supernatural. In fact, huge numbers of students now come to college knowing about at least one late medieval alchemist, Nicolas Flamel (ca. 1330 – 1418). They know about Flamel because he is a character in the first Harry Potter novel by J.K. Rowling. Here is the passage in which Rowling describes Flamel and his alchemical activities:
“Nicolas Flamel,” [Hermione] whispered dramatically, “is the only known maker of the Sorcerer’s Stone!”
This didn’t have quite the effect she’d expected.
“The what?” said Harry and Ron.
“Oh, honestly, don’t you two read? Look – read that, there.”
She pushed the book toward them, and Harry and Ron read:
The ancient study of alchemy is concerned with making the Sorcerer’s Stone, a legendary substance with astonishing powers. The Stone will transform any metal into pure gold. It also produces the Elixir of Life, which will make the drinker immortal. There have been many reports of the Sorcerer’s Stone over the centuries, but the only Stone currently in existence belongs to Mr. Nicolas Flamel, the noted alchemist and opera lover. Mr. Flamel, who celebrated his six hundred and sixty-fifth birthday last year, enjoys a quiet life in Devon with his wife, Perenelle (six hundred and fifty-eight). (pp. 219-220)

In the original UK version of this book, the “Sorcerer’s Stone” is called the “Philosopher’s Stone,” which is the name medieval and early modern alchemists actually used. Alchemists like Flamel sought to transform base metals like lead into more noble metals like gold and silver. And some of the, particularly in the sixteenth and seventeenth centuries, were even more ambitious, seeking to create and extend life. One of the delightful features of the Harry Potter series for historians of science is the multiple references to characters, ideas and practices that are familiar from medieval and Renaissance science and medicine. If you’re interested in exploring these connections further, see Harry Potter’s World: Renaissance Science, Magic and Medicine. However, the downside is that these books perpetuate popular myths that subjects like alchemy and astrology (a subject taught at Hogwarts) were mystical, magical and fundamentally un-scientific.
Alchemy was actually a rational and scientific subject. Alchemists were interested in questions about the fundamental nature of matter, and they studied matter by doing experiments in laboratories. Indeed, the earliest use of the word “laboratory” was to describe the space where alchemists worked. Further, alchemy was taken very seriously by medieval and early modern intellectuals, especially those interested in natural philosophy. Two of the figures we have studied in connection with the revolutionary changes in astronomy were also deeply involved in alchemy. Tycho Brahe had an alchemical laboratory on the island of Hven. Isaac Newton actively pursued alchemical researches. Prominent members of the Royal Society, like Robert Boyle, were also alchemists. Further, many kings, queens, princes, princesses and other territorial rulers and aristocrats were deeply interested in alchemy. They built alchemical laboratories and supported the work of alchemists. Duke August of Saxony, the husband of Anna of Saxony whose experimental work I described earlier, had an alchemical laboratory and personally performed experiments in this laboratory. Because alchemy was an important part of intellectual life in the medieval and early modern periods, it behooves us as historians to take it seriously as well, and to examine the theory and practice of alchemy. If alchemy wasn’t a form of magic, what was it?
Alchemy, in late antiquity and the Middle Ages, was the ART and SCIENCE of transforming base metals into gold. Alchemy was an “art” in the sense that transforming one metal into another was a technological or craft process. Alchemy was about “making” gold in the same way that baking was about making bread. Just as bakers manipulated ingredients and heat to create bread, alchemists manipulated chemicals and heat to create gold. Alchemy was a “science” in the sense that alchemists strove to understand the basic principles underlying the processes they performed in laboratories. This separated alchemy from other craft processes like baking. Bakers did not typically care about the underlying properties of yeast and flour and exactly how these substances could be turned into bread. Alchemists did care about the underlying theoretical underpinnings of what they were doing. Another difference between alchemists and bakers (and other craftspeople) is that bread making is not a natural process. Although the ingredients that make up bread are all natural substances, these components never spontaneously come together in nature and form bread. But alchemists believed that they were replicating – or improving upon – natural processes. In the early modern period, alchemy came to be about transforming matter more broadly, and this included the possibility of creating artificial life, prolonging life or reanimating the dead.
In the Middle Ages (in both Europe and the Islamic world), alchemists were primarily interested in the transformation of metals. Alchemists believed that all metals were compounds of sulfur and mercury. In nature, sulfur and mercury joined together underneath the earth, and gradually developed into the various metals. The particular metal that developed depended on the purity of the sulfur and mercury, their proportions, and the amount of heat where the metal was developing. In a best-case scenario, very pure sulfur and mercury combined in just the right proportions and developed in a hot, dry underground location. In this case, the noblest metal of all – gold – would be formed. If the sulfur and mercury were tainted, or the maturation of the metal took place in cold, damp or dirty condition, then a less noble metal – like lead – would result. Alchemists believed that they could replicate and accelerate the natural process of the formation of metals. They could turn lead into gold by breaking the metal down into its constituent parts – sulfur and mercury – then refining and purifying these parts, and finally reconstituting the purified sulfur and mercury as gold by combining them and heating them. Alternatively, they might prepare the philosopher’s stone, a substance that had the power to permeate base metals, purify them and transform them into gold. These laboratory processes were analogous to what went on under the earth, but alchemists claimed they could make these processes happen faster and more reliably than they occurred in nature. In the course of their efforts to understand and manipulate metals, alchemists developed many laboratory processes familiar to chemists today: calcination, distillation, fermentation and sublimation. They also devised specialized apparatus like furnaces and alembics for distillation.
Alchemy became considerably more prominent and influential in the sixteenth and seventeenth centuries than it was in the Middle Ages. This was largely due to the work of Paracelsus (1493 – 1541). Paracelsus made a two-fold innovation in the field of alchemy. First, he added salt to sulfur and mercury as a basic principle or element. Second, he expanded these three principles to include all natural bodies, not just metals. In medieval alchemy, sulfur and mercury were the basic components of metals and minerals. The Paracelsian principles of salt, sulfur and mercury were the basic components of the entire cosmos. In this way, Paracelsus made alchemy an all-encompassing science of matter, rather than more narrowly the science of metals. Also, Paracelsian matter theory was, like atomism and corpuscularianism, a challenge to the traditional Aristotelian theory of the four elements.

Paracelsus was actually not particularly interested in changing lead into gold; he was far more interested in medicine than in metals. He saw his theory as a new way of understanding the body and explaining and curing disease. He advocated the use of “chemical remedies,” which could mean both medicines produced by distillation and medicines that used substances like mercury and arsenic. (Anna of Saxony was undoubtedly influenced by Paracelsus, although she may not have accepted all of his ideas.)
Under the influence of Paracelsus, the connections between organic and inorganic processes become much tighter. For example, medieval alchemists had used biological METAPHORS to describe the formation of metals in the earth. Just as male semen caused female menstrual blood to coagulate into a fetus, so the active male principle of sulfur acted on the passive female principle of mercury. But the analogies between sulfur and semen and between mercury and menstrual blood were just that: ANALOGIES. In the sixteenth century these become more than analogies. If the entire cosmos, including the human body, is made of salt, sulfur and mercury, then there is no essential difference between organic and inorganic phenomena. Further, just as alchemists could manipulate metals, so too could they manipulate organic processes, including life and death.
A number of alchemists believed it possible to create life in the laboratory. For example, Robert Boyle, a prominent and prolific alchemist, wrote that one could create toads or serpents. To do this, one should take a goose or a duck, kill it, pluck it, boil it, place it in a sealed vessel and leave it for two to three weeks in a warm environment (like horse dung). When the vessel was opened, one would find live toads or serpents. Paracelsus himself gave directions for creating an artificial human being, or a “homunculus”:
Let the Sperm of a man by it selfe be putrefied in a gourd glasse, sealed up, with the highest degree of putrefaction in Horse dung, for the space of forty days, or so long until it begin to bee alive, move, and stir, which may easily be seen. After this time it will bee something like a Man, yet transparent and without a body. Now after this, if it bee every day warily and prudently nourished and fed with the Arcanum of Mans blood, and bee for the space of forty weeks kept in a constant, equall heat of Horse-dung, it will become a true and living infant, having all the members of an infant which is born of a woman, but it will bee far lesse. This wee call Homunculus, or Artificiall. (153)
Paracelsus also claimed to be able to reanimate a dead animal:
. . . if that living Chicke be in a vessel of glasse like a gourd, and sealed up, burnt to a powder, or ashes in the third degree of Fire, and afterward so closed in, be putrefied with the exactest putrefaction of Horse-dung, into a mucilaginous flegm, then the flegm may be brought to maturity and become a renewed and new made Chicke. . . . (152)
(In fairness, many scholars do not believe this is an authentic work by Paracelsus. However, it was accepted as such in the sixteenth and seventeenth centuries, and it is evidence that at least SOME alchemists believed it was possible to create artificial human life and to revive the dead.)
Practical Alchemy in the Holy Roman Empire
Shifting our attention away from Paracelsus, I want to focus on a story about the day-to-day practices of alchemists. In the second half of the 16th century, the court of Duke Julius of Braunschweig-Wolfenbuttel offered many jobs for alchemists. The Duke was personally interested in alchemy and maintained a thriving workshop employing several alchemists at any given time. In 1571, Julius hired three new alchemists, Philipp Sömmering, Anna Maria Zieglerin, and Anna’s husband, Heinrich Schombach.
As the leader of the group, Sömmering negotiated terms for producing a couple of ounces of a tincture for transmuting metals (in layman’s terms this was powdered Philosopher’s Stone). Sömmering would be paid 2000 thaler (currancy of the time) and accepted into the court. The group was given cloth, a horse, a laboratory and housing while they worked.
The trio worked on producing the Philosopher’s Stone for three years, but in 1573 Sömmering was accused of fraud by two different people. The Duchess, who had always disliked Sömmering and Zieglerin seized the opportunity and initiated a year long investigation end. Sömmering was convicted and he and one of his assistants were dragged to the Muhlentor (the town square), their skin torn with red-hot, glowing tongs, and their bodies quartered alive and posted on the four roads into town. Zieglerin was strapped to an iron chair and burned to death. While this grisly death scene is interesting, it is instructive precisely because it was unusual.
The harsh punishment of this group was not because they failed to fulfill the terms of their contract but rather that they were “Betrüger,” charlatan alchemists. That the Germans had a word for charlatan alchemists implies that not all alchemists were charlatans.
Generally, when someone fails to live up to the terms of a contract, say for example that the cable guy shows up two hours late, or you forget to pay your phone bill on time, we do not brutally murder that person in the town square. Similarly, if an alchemist failed to live up to their contract during the 16th century, generally they were forced to reimburse their fees or were sued for damages. In fact, we know quite a lot about alchemical contracts from this time period because many have survived. Alchemists wrote letters describing procedures and proposing deals, and contracts were negotiated for salaries, expectations and materials. From labs like that of Julius we have not only work contracts, but also architectural plans for the building and inventories of the glassware, furnaces, chemicals and materials. We even have rejected applications showing ideas that were never pursued and legal records from failed contracts.
Paintings from this time period also tell us something about the cultural understanding of alchemy:
From the contractual history and in the images, we can see that a wide variety of alchemical goals were pursued. The traditional, big ideas of alchemy, the Philosopher’s Stone, the Elixir of Immortality, and the Homunculus, were pursued, but so were a variety of more practical products like dyes, paints, simple medicines, and mineral solutions. An alchemist might be employed to make vinegars, wines, and beers. An alchemist would be useful for metallurgy or minting coins. An alchemist could also be useful in agriculture for studying the natural processes of soils and plants.