The year was 1989. Principe was ensconced in the archives of London's Royal Society with a book of unindexed 17th-century papers, part of a trove of 15,000 hand-scribed pages. He was reading when his eye lingered on a phrase. The author of the text was describing a process for dissolving gold: "[the gold is] wont to melt as it were naturally...(almost like Ice in luke-warm water)."

"That doesn't sound striking," Principe says today, "unless you've been reading alchemical writings."

Boyle (1627-91) and contemporaries Isaac Newton and John Locke were, in the eyes of historians, the founders of the scientific method, the men who led natural philosophers--the scientists of the day--away from occult practices like alchemy into the light of rational, objective, experiment-based science. Biographer after biographer and historian after historian had missed or dismissed previously noticed hints of Boyle's interest in transmutation. But Principe knew in his gut that Boyle was not likely to have written "like Ice in lukewarm water" unless he had been an alchemist.

Principe spent the next eight years assembling his argument, and in The Aspiring Adept: Robert Boyle and His Alchemical Quest (Princeton, 1998), he makes his case: The "father of modern chemistry," says Principe, spent 40 years seeking the recipe for the Philosopher's Stone and carrying out alchemical experiments. He did all those scientific things for which he's justifiably famous, including discovering Boyle's Law of Gases. But he was also an active and enthusiastic alchemist. Writing about the book, Seymour Mauskopf, professor of history of chemistry at Duke University, said that it "will stand the traditional view of Boyle as a progenitor of modern science on its head."

Which is okay with Principe. He says, "I can think of a few historians who are going to have a conniption." He smiles when he says it.

PRINCIPE, A 36-YEAR-OLD ASSISTANT PROFESSOR at Hopkins, occupies a Mergenthaler Hall office cluttered with the materials and artifacts of his three scholarly pursuits. He holds a joint appointment in the departments of Chemistry and History of Science, and is unofficially a one-man department of alchemy. Books and papers are everywhere, even stacked on the steps of a wooden ladder. A fume hood for chemical procedures dominates one wall. Principe's office has become a de facto museum for the history of chemistry at Hopkins. He keeps a brace of beautiful old balances, and a voltmeter and ammeter from the 19th century.

On the wall behind his computer hangs a framed portrait of Robert Boyle. Principe has noticed that for some reason many paintings of alchemists included wildlife specimens scattered about the lab. Principe, who in another century might have been an adept himself, as those who "knew" the secret to transmutation were called, has suspended a preserved blowfish from his ceiling. He says he's on the lookout for a stuffed crocodile.

Larry Principe was one of those kids who periodically used a home chemistry set to pervade the basement with noxious fumes. "Our house must have been well-ventilated," he says, "since I didn't kill myself. My parents did buy me a couple of fire extinguishers." He also collected 19th-century books on chemistry, and recalls a library volume on alchemy that prompted a question that would linger in his mind as he attended the University of Delaware: "I began to wonder if anyone had tried to find out what these people really had been doing."

In 1980, Principe was a sophomore majoring in chemistry and liberal studies (he tends to pick up degrees in pairs) when Delaware purchased an uncataloged library of several thousand books on the history of chemistry. He could not have been happier. The faculty gave him permission to go through the collection, and he came across a 1604 first edition of Triumph-Wagen Antimonii, or The Triumphant Chariot of Antimony, by an obscure 16th-century alchemist who wrote under the name Basil Valentine.

Alchemy was practiced for 1,500 years, starting in Hellenized Egypt in the 3rd century. The term covers a variety of early chemical activities: working with alloys, purifying metals, assaying, refining, preparing salts, formulating medicinal compounds, searching for solvents. Alchemists wrote in a strange, allusive fashion that requires deciphering if you want to fathom what they were doing. Principe decided to translate the book from the original German and Latin, and to replicate as many of the experiments as possible.

He took this interest with him when he went to Indiana University to complete a PhD in organic chemistry. Indiana had a department of history and philosophy of science, and Principe found himself increasingly drawn to historical scholarship. He was fascinated by a dozen drawings from a manuscript first published in 1599 and known as the "12 Keys of Basil Valentine." The drawings are coded recipes for alchemical processes. Principe had figured out most of the recipes in The Triumphant Chariot of Antimony. He looked at the "12 Keys" and wondered if he could do it again.

Some proved easier than others. The second is an image of a winged figure of Mercury grasping a caduceus in each hand. At his feet is a set of wings, and to each side is a warrior. One warrior holds a sword around which is coiled a serpent; the other carries a blade with a bird perched on its tip. Principe, from his experience reading alchemical texts, unlocked the image: "The bird that flies [on one combatant's sword] represents something volatile, probably sal ammoniac. The snake is potassium nitrate. Combine those ingredients and heat them and you get a volatile acid--that's Mercury standing on the wings." In the background are images of the sun and moon: "The acid can dissolve gold [the sun] and corrode silver [the moon]."

Principe was intrigued. Volatilizing gold was an alchemical pursuit. Had Boyle, the man revered for leading chemistry out of the occult shadow of alchemy, been an aspiring adept himself?

By 1988, Principe had grown less enamored with the practice of chemistry and become more interested in historical scholarship. He preferred working alone in a library to managing a lab and hustling grants. So he came to Hopkins to earn a second PhD, this one in history of science. He hadn't forgotten that intriguing reference to Boyle and the volatilization of gold. A year later, he spent four or five days in London examining the Royal Society's Boyle archive. He says, "If Boyle were hiding something, the likely place to look was in his private papers."

Principe began thumbing through the bound volumes of Boyle's papers, and did indeed find notes on a process to volatilize gold: "That's when things started going off, because the method he described was identical to the one I'd deciphered from Basil Valentine's 12 keys. He even made reference to Valentine's text, specifically the [second] image of the two fighters."

Why was Boyle citing Valentine? Principe knew only the basics about Boyle, but he knew that "the father of modern chemistry" was supposed to have repudiated alchemy. And here Boyle was citing an alchemist and reproducing his recipes. Something wasn't right. Principe read on. He found laboratory records written in code and accounts of experiments on alchemical products. He found tantalizing fragments of a dialogue on transmutation, a text other historians had mentioned but believed no longer existed. He recalls, "At this point, it's certain that I'm on to something big here." What had begun as a routine PhD dissertation on Basil Valentine was transmuting into something much more valuable.

In 1990, he paid his way back to London for another look. Boyle's papers had been written in mostly English, Latin, and French, in 50 different hands by various correspondents and scribes, as well as by Boyle. For 10 days he read the archive, page by page. He found copies of alchemical treatises, complete with Boyle's notes on them. He found additional lab records, and more fragments of the mysterious dialogue. "It became clear that not only was Boyle reading the alchemical writers, he was deciphering them and trying their experiments himself," he says. "And more important, he was doing so for the transmutation of gold."

Now Principe knew. Robert Boyle had been an alchemist.

The importance to Boyle of alchemy became ever more apparent as Principe combed through the archive. One of the principal achievements of The Aspiring Adept is Principe's reconstruction of Dialogue on the Transmutation and Melioration of Metals, a fictional debate on the feasibility of transmuting one of the base metals--lead, tin, copper, iron, or mercury--into gold. Principe took 23 fragments, which were first and second drafts and assembled what he believes to be much of the original text. The dialogue is a debate among several members of a "Noble Society" (probably modeled on the Royal Society of London, of which Boyle was one of the founders) as to the possibility of transmuting lead into gold. Erastus, the skeptic of the group, asserts that the Philosopher's Stone is a fiction, and summarizes four arguments against its existence. Another member of the society, Zosimus, counters that Erastus has merely proved the Stone to be improbable, not impossible. The debate goes back and forth. The verdict, in the end, is in favor of the possibility of transmutation.

Fragment 10 of the dialogue, actually the last part found by Principe, is an account by one Philoponus of his own firsthand experience of a successful transmutation. As he read it, Principe became more and more excited. Philoponus was fluent in French; so was Boyle. Philoponus was wealthy enough to have a servant waiting outside with his carriage; Boyle was similarly well off. Philoponus complains of an eye ailment that makes gazing at firelight, even candlelight, painful. Boyle had written about suffering from the same affliction. "As I read it, I was just blown away," Principe says. "I realized that this was actually Boyle's firsthand account of witnessing transmutation." Bolstering Principe's argument are notes by Gilbert Burnet, bishop of Salisbury, of a conversation in which Boyle tells of observing an itinerant adept perform transmutation. Burnet's notes include Boyle's description of holding the resultant gold in his hand.

Principe discovered that Boyle sometimes went to improbable lengths to pursue alchemical knowledge. For example, Principe found a dozen letters from a Georges Pierre of Caen, who claimed to represent "Georges du Mesnillet, Patriarch of Antioch." The "patriarch" claimed to lead a secret society of adepti called the Asterism. This society, said Pierre, included Chinese and Indian alchemists, had use of a castle in France named "Herigo," and in 1678 had nominated Boyle for membership. To join, Boyle was advised to take certain steps, outlined by Pierre. These included joining the Turkey Company (the English merchant company that conducted trade with the Levant) and sending numerous gifts to the Turkish sultan. The letters indicate that Boyle had followed as many of Pierre's instructions as he could, but before he could be inducted into the Asterism, he heard from Pierre that a suspicious King Louis XIV of France had arranged for an explosion to destroy Herigo, killing 30 of the adepti and dispersing the organization.

The whole tale, for many reasons, sounds like a con job. But what's important, Principe says, is what it illustrates about how far Boyle would go to learn more about what adepti were doing. Boyle corresponded with many alchemists. He financed alchemical labs elsewhere in England and on the continent. He collected accounts of witnesses to transmutation. In 1689, he lobbied for repeal of the Act of Multipliers, enacted in 1404, which prohibited using transmutation to "multiply" gold and silver. It's hard to imagine how Boyle could have been more involved.

THROUGHOUT THE ASPIRING ADEPT, Principe marshals considerable evidence of Boyle's alchemical pursuits. There are places where he has to conjecture, and where his interpretation of documentary evidence is open to dispute. But his case for Robert Boyle, Alchemist, is compelling. How did so many previous biographers and historians get it wrong?

For one thing, Principe says, until recently no one had cataloged the Boyle archive, so nobody knew what it contained. Nor was anyone enthusiastic about finding out. Says Principe, "A lot of scholars don't want to wade through that sort of thing to make sense of it all." People who had dipped into it, he believes, may have come across evidence of alchemy but not known what they were reading, because they didn't understand the metaphors and the codes. They didn't know that "Jupiter" meant tin, or that when Boyle wrote "extract the Negirus from Banasis and Dicla," he meant "extract the Mercury from antimony and copper." The evidence was before them--they simply couldn't decipher it.

But such acknowledgment runs counter to a second image: Boyle as the founder of modern chemistry. The burnishing of that image began long before the modern history of science. Eight years after Boyle died, the first condensed accounts of his work began appearing, and already the publishers were downplaying or ignoring Boyle's writings on alchemy. In 1734, Thomas Birch wrote an entry on Boyle for Pierre Bayle's General Dictionary, in which he devoted attention to Boyle's work on transmutation. Ten years later, when Birch wrote Life of Boyle, he made little mention of alchemy. Authors invented a struggle between science and alchemy, and cast Boyle as the leader of science. J.F. Gmelin, writing in 1797, described Boyle's founding of chemistry as the "first rays of light...into the mist of alchemical and theosophical error." This attitude prevailed through the 19th century.

In the 20th century, he says, historians still considered alchemy to be pseudo-science. George Sarton in the 1930s and '40s saw Boyle as "one of the best prototypes of the modern man of science," and alchemists as "fools and knaves." How inconvenient that Boyle had left behind so many indications that he was also a fool and knave. Sarton tried to explain away the evidence available even then: "Boyle was not an alchemist, although he accepted the postulate that the transmutation of metals was possible." Other historians ignored what was before them, Principe says. They concentrated on Boyle's writings of the 1660s, when he was noncommittal about alchemy, and downplayed his writings in the 1680s, when he was devoted to transmutation. Says Principe, "They're an older generation of historians who see history as this grand progression leading up to us, and what doesn't lead up to us is not worthy of consideration." Alchemy, he says, falls out of the narrative because it has been deemed unworthy by this positivist viewpoint.

Marie Boas Hall, a prolific historian who began writing in the 1950s, has continued this pattern. Her portrait of Boyle in Robert Boyle and Seventeenth-Century Chemistry (1958) and Robert Boyle on Natural Philosophy (1965) has been the dominant one, until now. Principe's scholarship takes aim at her, and especially at more recent scholarship that takes her portrait at face value.

So far, Principe says, his radical rewriting of Boyle's life has been well received.

SOMEONE WHO ACCEPTS Principe's evidence and arguments still faces a troubling question about Boyle: How could someone as intelligent, observant, and dedicated to scientific inquiry believe so stoutly in transmutation? After all, this was a science in which no one ever wrote a straightforward recipe for the Philosopher's Stone. Instead, adepti always couched their accounts in opaque metaphorical language, hidden behind codes and deliberately fragmented to make them hard to read. Testimonials of transmutation invariably follow a pattern: "I have been told by this person of repute that he witnessed transmutation on November the 25th of the year 1653, in the quarters of a Mr.____ in Rouen. Herein is his recipe for the Stone. I have not been able to use the recipe to create the Stone myself, but this testimony is to be believed as a true and accurate account, and verifies that transmutation is possible." How could anyone, year after year, continue to believe such stories when no one, not even a genius like Newton, could reproduce the alleged results?

To understand this, says Principe, you must understand Boyle's theology. Boyle was a devout Christian, much concerned by the increase of atheism in England and elsewhere. He refused, says Principe, to accept "the universal negative"; that is, he refused to disbelieve something just because it couldn't yet be explained or demonstrated. If one were to disbelieve an alchemist's account simply because it was incredible, then one had to disbelieve the accounts of the Apostles as well. Were their stories not incredible and inexplicable? Boyle was a man of intellectual consistency, Principe argues. He couldn't accept Scriptures as truth, then turn around and discount alchemy just because the stories of the adepti seemed beyond rational explanation.

Principe was startled, during his investigation, to find unpublished documents revealing Boyle's belief that the Philosopher's Stone would enable him to communicate with angels. In a fragment of an unpublished dialogue, Boyle wrote that finding the Stone might prove an inlet to "the attainment of some intercourse with good spirits." If the Stone could demonstrate the existence of "rational spirits," would that not demonstrate the existence of God? Boyle believed, says Principe, that the Stone might be able to transmute more than gold. It might transmute atheists. Boyle subscribed to the Stone's existence, says Principe, because there was no good reason for him not to believe it, and because his theology, which was never divorced or separate from his science, required him to believe it.

Principe wonders what else might be waiting for the right pair of eyes to turn it up. He is tantalized by the thought that a complete manuscript of the Dialogue on the Transmutation might be out there somewhere, unrecognized, uncataloged. And then there's that castle at "Herigo." What if it existed? Finding it would be like finding the Troy of alchemy. Wouldn't that be something?

Dale Keiger is a senior writer at Johns Hopkins Magazine.

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