When Cambridge University, Newton’s alma mater, had acquired the trove in 1872, a team of scholars had dedicated sixteen years to cataloging the contents. This was Newton, after all, and they were hungry for any insight into how he’d developed his theories of motion, gravity, light, and color—work that defines the very Newtonian universe we inhabit.
Strangely, after riffling through and picking out select papers, Cambridge returned virtually the entire bundle to the owner, the Earl of Portsmouth. Soon forgotten, the chest barely survived a house fire in 1891, and by 1936 one of the Earl’s descendents was selling it to make some quick cash. Sotheby’s itself barely publicized the sale—it was easily overshadowed that season by a spectacular, £140,000 auction of Rubens and Rembrandt paintings through rival house Christie’s. As the gavel fell for the last time at Sotheby’s on July 14, the bulk of Newton’s life’s work had been split up among three dozen book buyers for a pitiful £9,000.
Economist John Maynard Keynes, a Newton admirer, was one of those three dozen, though he’d heard about the auction too late to buy much. Disturbed by the “impiety” of the transactions, he began acquiring more of the papers piecemeal. In many cases, he had to play the slick antiquarian, swapping Newton papers with collectors, trying to out-connive them. Keynes later remembered, with a touch of Bloomsbury snobbery, “I managed gradually to reassemble about half of them. . . . The greater part of the rest were snatched out of my reach by a syndicate which hoped to sell them at a high price, probably in America.”
Keynes sought papers on any topic at first, but eventually concentrated on one niche—Newton’s alchemy. Few people knew the father of modern science had dabbled in alchemy; but the more Keynes collected and the more he “brood[ed] over these queer collections,” the clearer it became that alchemy wasn’t a niche to Newton at all. It was, in many ways, Newton’s life work—more vital to him than physics or mathematics ever was. This Newton “was not the first of the age of reason,” Keynes concluded. “He was the last of the magicians.”
Keynes’s findings threw the standard narrative of science history into confusion. Keynes re-donated the alchemical papers to Cambridge in 1946, but most historians, still nonplussed, either ignored them or tried to explain them away. In fact, only recently have scholars begun to systematically study the entire corpus, line by line, picture by picture, rune by rune. Those efforts are getting a big boost from Assistant Professor of Library and Information Science John Walsh and science historian William Newman, both at Indiana University, who head a project to digitize and post online the thousands of pages that Newton wrote on alchemy. One quarter has been posted so far, but Newman and Walsh say they’ve already gleaned insights into not only Newton the man, but into how alchemy shaped Newton’s science.
Early in life Newton turned to alchemy as a diversion. His father died before he was born (Newton, a sickly infant, almost joined him in the grave), and Newton grew up with a distant stepfather who kept the boy’s mother away from him. Nor did Newton, too precocious for his own good, make friends among his peers.
As compensation, he disappeared into books like Mysteries of Nature and Art—fascinated by their odd mix of occult philosophy and practical engineering. Showing early ingenuity, Newton built a water clock and other contraptions described in Mysteries; showing an early mischievous streak, he also built a lantern described therein, tied it to a kite, and flew it at night near his home, a spectacle “which wonderfully affrighted all the neighboring inhabitants,” he recalled. At Cambridge, Newton further developed his interest in both the practical and theoretical sides of the field, devouring books by alchemist Robert Boyle.
Newton described such work as chymistry. And the word is a useful reminder—with its echo of modern “chemistry,” yet archaic spelling—of what alchemy meant to people in Newton’s time. Today, most people think of alchemists as either foolish necromancers or lowlifes obsessed with chrysopoeia—turning base metals into gold. That view comes down to us largely through the enemies of alchemy, Enlightenment thinkers, for example, who wanted to stamp out “magical” thinking and, ironically, install a mechanistic, “Newtonian” outlook instead. But alchemists were important for humankind’s intellectual development—the larvae that metamorphosed into Enlightenment philosophes and modern scientists. Especially important was the later alchemists’ willingness to test their theories with experiments, even theories that conflicted with accepted doctrines. Boyle was the primary example here, but John Locke, Gottfried Leibnitz, and others exchanged letters with and befriended alchemists, too, looking to chymistry for wisdom about the natural world.
Newton’s chymistry followed this tradition in many ways, Newman says, especially his view of nature as a riddle that only a gnostic brotherhood of alchemists could unravel. At the same time, Newton was unique among alchemists for uniting his chymistry with other, seemingly disconnected scientific obsessions of his, such as optics. Newman even argues that Newton’s famous demonstration that white light was merely a combination of colored light rays owes a significant debt to the alchemy of Boyle.
In the 1660s, Boyle got tangled up in a dispute with scholastic philosophers over the essence of matter. These adherents of Aristotle believed that once a substance dissolved into something else, it lost its identity forever. Boyle devised an experiment to dissolve camphor, an aromatic chemical, in acid, at which point the camphor lost its scent. This agreed with scholastic thought. But Boyle then added water to the solution—at which point the camphor reappeared, regaining its odor and all other properties. Boyle could pull similar tricks with dissolved metals like gold. This classic alchemy proved scholastics wrong, Boyle said: Dissolved substances don’t lose their identity.
The scholastics retorted that there was no proof it was really the same camphor. When the water was added, the solution might have created the camphor anew. But Boyle rejected this reasoning. Why, he argued, should the camphor’s essence be any different because it came from an experiment and not from nature? If it talked like camphor and walked like camphor, it was camphor, period.
Newton studied Boyle’s arguments, and soon devised a similar theory about color. While on leave from Cambridge during an outbreak of plague, Newton began separating sunlight into colors with a prism, among other experiments. He thought they proved that colored lights were “in” white light from the start. Colleagues like the eminent Robert Hooke disagreed, arguing that the prism itself could have produced the colors as light streamed through, the way an organ pipe produces sound when air rushes through. (No one would say that sharps and flats are “in” the pipe before they’re played.)
To counter this objection, Newton adopted Boyle’s tactics. He showed he could tease white light apart into reds, yellows, greens, and blues, then meld them back together. Crucially, this synthesized white light had all the properties of sunlight. Newton argued from this that the individual colors in light had a permanent, incorruptible existence, even if humans couldn’t always sense them. Boyle had made the exact same logical points about the permanence of camphor in acid. According to Newman, Newton’s fundamental theory of color was therefore midwifed by Boyle’s alchemy.
This success with color and chymistry must have thrilled Newton—he’d uncovered secrets in nature and a little magic of his own. And although Newton expanded his work into gravity and astronomy (not to mention Biblical prophecies, another obsession), he felt pulled back to chymistry his entire working life. Indeed, he dedicated six weeks to chymistry every fall and every spring for decades, the seasons when his unheated lab was bearable—and he often worked through the unbearable months, too. In all, Newton penned over one million words (five hundred times the length of this article) on chymistry.
Merely counting words doesn’t capture the richness of the chymical work. Like all alchemists, Newton peppered his prose with gnomic shorthand. Consider this line in a recipe for “sophic mercury,” which dissolved gold and allowed the precious metal to “vegetate” and mature into the philosopher’s stone: “Marry [sulfur] with , that is our [mercury] which is impregnated with must be espoused with our gold then hast thou two sulphurs married & two s of one of[f]spring whose father is the [gold] & [silver] the mother.”
Newton also included allegorical drawings, like a head with three faces or an elaborate caduceus crowned with a Holy Spirit dove, and verses copied verbatim from other alchemists. Moreover, those million words don’t capture the countless hours Newton spent running chymistry experiments on intriguing substances like antimony and mercury. Doctors in later eras have even speculated that Newton suffered from chronic mercury poisoning as a result, which could certainly explain his peculiar personal life.
Given how much labor went into Newton’s chymistry, why did none of it come to light until the Sotheby’s auction? It wasn’t all genteel scholarly embarrassment. English alchemists had to veil their true interests because alchemy had been illegal in England since 1404. The crown feared alchemy because transforming lead into gold would have destabilized the country’s economy, through counterfeit coins. The general ban on alchemy—the Act Against Multipliers—was lifted in 1689, thanks to Boyle’s lobbying, but alchemists were still tainted by association, and counterfeiting remained a capital crime in England. (When Newton took over as director of the Royal Mint in his dotage, in fact, he had one notorious counterfeiter hanged and publicly disemboweled—and took great delight in seeing it done.)
Still, the illicit nature of chymistry doesn’t completely explain why Newton concealed his research (Boyle didn’t). There’s no delicate way to put it: Almost everyone who knew him found him disarmingly weird. He had a mean temper, probably never had sex, and suffered at least one raving breakdown, during which he wished death on Locke, one of his few friends. Thoughts of sin tormented Newton. As a young man he wrote a letter addressed to God outlining every peccadillo he ever committed, faults ranging from the touchingly innocuous—“making pies on Sunday night”—to the abusive and creepy—“punching my sister” and “threating my [step]father and mother . . . to burne them and the house over them.”
This eccentricity spilled over into his science. Curious what would happen, Newton once stared into the sun for so long he had to lie in a dark room for several days before he stopped seeing spots. He also once wedged a needle into the socket behind his eye, to see how changing the curvature of the eyeball affected his vision. But for someone willing to experiment on just about anything, Newton was very guarded about discussing his experimental results, especially in chymistry. He loathed the thought of someone figuring something new out from his ideas, and he was obsessed with getting full credit for discoveries. (This desire bared its teeth in the 1680s when Leibnitz published a theory of calculus independent of Newton’s earlier but unpublished work, at which point Newton set out to destroy Leibnitz’s reputation.)
But really, can we blame Newton for being so secretive, for obsessing? For him, so much was at stake. He wouldn’t have recognized the distinction we draw today between “real” science full of experiments and equations and alchemical pseudoscience full of spells and bootless speculation. Chymistry was one grand body of work to him, the grandest, and he’d coveted knowing nature’s secrets since boyhood. He labored so long and so secretly because chymistry seemed the most promising path to obtaining near-magical powers and near-mystical insights into nature—discoveries that would, if only he could make them, vault him into the first rank of geniuses who ever lived.