Alchemyand Heresy

In his nineteenth-century biography of Newton, David Brewster surprised his
readers with an astonishing discovery. He revealed for the first time that Newton’s
papers included a vast collection of books, manuscripts, laboratory notebooks,
recipes, and copied material on alchemy. How could “a mind of such power . . .
stoop to be even the copyist of the most contemptible alchemical poetry,” Brewster
asked. Beyond that he had little more to say about Newton the alchemist.
By the time Brewster wrote his biography, alchemy was a dead and unlamented
endeavor, and the modern discipline of chemistry was moving forward
at a rapid pace. In Newton’s century the rift between alchemy and chemistry was
just beginning to open, and in the previous century alchemy was chemistry.
Alchemists, like today’s chemists, studied conversions of substances into other
substances, and prescribed the rules and recipes that governed the changes. The
ultimate conversion for the alchemists was the transmutation of metals, including
the infamous transmutation of lead into gold. The theory of transmutation had
many variations and refinements, but a fundamental part of the doctrine was the
belief that metals are compounded of mercury and sulfur—not ordinary mercury
and sulfur but principles extracted from them, a “spirit of sulfur” and a “philosophic
mercury.” The alchemist’s goal was to extract these principles from impure
natural mercury and sulfur; once in hand, the pure forms could be combined
to achieve the desired transmutations. In the seventeenth century, this
program was still plausible enough to attract practitioners, and the practitioners
patrons, including kings.
The alchemical literature was formidable. There were hundreds of books
(Newton had 138 of them in his library), and they were full of the bizarre terminology
and cryptic instructions alchemists devised to protect their work from
competitors. But Newton was convinced that with thorough and discriminating
study, coupled with experimentation, he could mine a vein of reliable observations
beneath all the pretense and subterfuge. So, in about 1669, he plunged into
the world of alchemy, immediately enjoying the challenges of systematizing the
chaotic alchemical literature and mastering the laboratory skills demanded by
the alchemist’s fussy recipes.
Newton’s passion for alchemy lasted for almost thiry years. He accumulated
more than a million words of manuscript material. An assistant, Humphrey Newton
(no relation), reported that in the laboratory the alchemical experiments gave
Newton “a great deal of satisfaction & Delight. . . . The Fire [in the laboratory
furnaces] scarcely going out either Night or Day. . . . His Pains, his Dilligence at
those sett times, made me think, he aim’d at something beyond ye Reach of
humane Art & Industry.”
What did Newton learn during his years in company with the alchemists? His
transmutation experiments did not succeed, but he did come to appreciate a
fundamental lesson still taught by modern chemistry and physical chemistry:
that the particles of chemical substances are affected by the forces of attraction
and repulsion. He saw in some chemical phenomena a “principle of sociability”
and in others “an endeavor to recede.” This was, as Westfall writes, “arguably
the most advanced product of seventeenth-century chemistry.” It presaged the
modern theory of “chemical affinities,” which will be addressed in chapter 10.
For Newton, the attraction forces he saw in his crucibles were of a piece with
the gravitational force. There is no evidence that he equated the two kinds offorces, but some commentators have speculated that his concept of universal
gravitation was inspired, not by a Lincolnshire apple, but by the much more
complicated lessons of alchemy.
During the 1670s, Newton had another subject for continual study and
thought; he was concerned with biblical texts instead of scientific texts. He became
convinced that the early Scriptures expressed the Unitarian belief that although
Christ was to be worshipped, he was subordinate to God. Newton cited
historical evidence that this text was corrupted in the fourth century by the introduction
of the doctrine of the Trinity. Any form of anti-Trinitarianism was
considered heresy in the seventeenth century. To save his fellowship at Cambridge,
Newton kept his unorthodox beliefs secret, and, as noted, he was rescued
by a special dispensation when he could no longer avoid the ordination requirement
of the fellowship.