History & Culture

Sir Isaac Newton & The Philosopher’s Stone

Sir Isaac Newton died today in 1727. To remember the “father of modern science,” experts at the Chemical Heritage Foundation look at his lesser known study of alchemy and its role in his scientific musings.

As soon as James Voelkel, the curator of rare books at the Chemical Heritage Foundation (CHF), saw Isaac Newton’s 17th-century manuscript at auction preview in February 2016, he knew it was authentic. First, there was Newton’s distinctive handwriting that was familiar to Voelkel. Then there was the way in which Newton created the manuscript, by taking a much larger sheet of paper, folding it in half twice, and cutting halfway along one of the folds to make a small pamphlet. Voelkel had seen such makeshift notebooks before, through his work with The Chymistry of Isaac Newton, a project curated by William R. Newman at Indiana University that provides scholarly online access to Newton’s alchemical manuscripts.

By folding the paper in this way, Newton was able to copy and annotate lengthy recipes for experiments in alchemy. In this case, Newton had copied a recipe titled Praeparatio Mercurii ad Lapidem per Regulum Martis Antimoniatum Stellatum et Lunam ex Manuscriptis Philosophi Americani, Latin for “Preparation of the [Sophick] Mercury for the [Philosopher’s] Stone by the Antimonial Stellate Regulus of Mars and Luna from the Manuscripts of the American Philosopher.” But once the manuscript’s writer was verified, a much larger question emerged: What did this document suggest about how alchemy influenced Newton, the brilliant physicist, astronomer, and discoverer of calculus?

Like the cryptic recipes themselves, much remains enshrouded in mystery about Newton’s reasons for studying this precursor to modern chemistry. Perhaps equally puzzling has been the public’s changing awareness of Newton as an alchemist, which has shifted dramatically in the centuries since his death in 1727. And since today marks the anniversary of Newton’s death, it seems fitting to look more closely at Newton’s fascination with alchemy through the lens of CHF’s latest Newton acquisition.

Why did Newton seek the philosopher’s stone?

Newton wrote an estimated 1 million words on alchemy. According to Voelkel, “Many people don’t know about Newton’s alchemical work, but it was hugely important because it occupied a large part of his intellectual attention.” Much like Newton’s groundbreaking contributions to numerous branches of science, his studies of alchemy spanned decades and were extensive in focus and application. Evidence suggests that alchemy influenced everything from Newton’s discoveries about the spectral properties of white light to his understanding of the nature of matter in terms of tiny particles. Of course, a portion of Newton’s alchemical experiments did focus on metallurgy and the transmutation of one metal into another.

“Newton did a huge range of different kinds of alchemical experiments,” Voelkel said. “But without question, just like all the others, attempting to make gold was part of it.” 

The sophick mercury mentioned in the manuscript’s title was also known as “philosophic” mercury, which alchemists believed could break metals down into smaller components that could then be used to make different metals. This process was key to creating the philosopher’s stone, the legendary substance that could transform base metals like lead into gold. 

“Alchemists thought metals were compound,” Voelkel said. “And if you could jigger with the proportions in the compound, you should be able to change one metal to another. It was perfectly reasonable to expect.”

What’s also remarkable about this particular recipe are Newton’s annotations. As he copied the recipe, Newton corrected some of the measurements, noting in brackets where he believed the proportions were incorrect. In addition, on the back of the manuscript, Newton wrote notes in English for one of his own laboratory experiments for distilling a spirit from lead ore. So while the manuscript itself neither explains how sophick mercury could be used to create the philosopher’s stone nor concludes that Newton tried to create sophick mercury, the profound impact that alchemy had on Newton’s studies is undeniable.

Who was the American philosopher?

Beyond Newton’s interests in the philosopher’s stone, this manuscript is also noteworthy for the way in which it connects Newton to one of his favorite alchemists. The recipe was originally written by Eirenaeus Philalethes, or “a peaceful lover of truth,” which was the pseudonym of George Starkey. According to Voelkel, “Starkey was America’s first internationally known scientific figure.”

Roughly a century before Benjamin Franklin’s experiments with electricity, Starkey gained prominence in the mid-1600s studying alchemy at Harvard College. He then moved to London, where he pursued his chemistry studies and influenced prominent leaders of the Scientific Revolution, including Newton, Robert Boyle, and John Locke. It was also in London that Starkey began writing under the guise of his alchemical pen name. In fact, it’s possible that Newton obtained this recipe directly from Boyle, a contemporary and alchemical collaborator who had studied directly under Starkey. Ironically, Newton and Boyle never knew the true identity of the “American philosopher.” That secret remained hidden until William R. Newman, a professor at Indiana University and head of The Chymistry of Isaac Newton, discovered it in the 1990s.

Why isn’t Newton more widely associated with alchemy?

Around the time of Newton’s death, alchemy became maligned. Voelkel explained that as chemists increasingly sought professional recognition, they had to distance themselves from alchemy’s gold-making focus, which was considered to be disreputable. Chemistry was then rebranded and redefined, relegating alchemy to pseudoscience status.

Sir Isaac Newton

A portrait of Newton investigating light by J A Houston, circa 1879. 

That professional bias against alchemy was largely applied to Newton until the 20th century. Cambridge University, where Newton studied, even passed up a donation of Newton’s alchemical manuscripts in the late 19th century, though now it possesses many of those manuscripts.

“In the modern era,” Voelkel said, “some of the earliest serious Newton biographers and people who studied Newton’s science denied that Newton had done alchemy. And when they were forced to admit it, many tried to twist things around and say things like, ‘Well, he was doing chemistry but he wasn’t really trying to make gold. The truth is that he was trying to make gold, just like the rest of them.’”

As more of Newton’s alchemical manuscripts have become publicly available, researchers have been able to examine alchemy’s influence on Newton more closely, as well as the vital role alchemy played in the history of chemistry. At the Chemical Heritage Foundation, Newton’s recipe for sophick mercury has become symbolic of a much larger collection of rare books, which includes first editions of Newton’s Opticks and Principia in addition to extensive holdings of alchemical books in general from the 16th to 18th centuries, all of which are available for research. Meanwhile, the institution continues to find innovative ways of utilizing its collection to engage the public about alchemy, including museum exhibitions such as the current Transmutations: Alchemy in Art and an alchemy video game, currently in development.


Zack Pelta-Heller is the web content manager at the Chemical Heritage Foundation in Philadelphia.