Approximately how many words did Isaac Newton write on alchemy?

Approximately how many words did Isaac Newton write on alchemy? About 1,000,000 words. That astonishing estimate comes from examining Newton’s surviving papers, which contain roughly 10 million words overall. Around a tenth of that material concerns alchemy, a subject Newton pursued with extraordinary seriousness alongside mathematics, physics, theology, and biblical chronology.

Newton’s alchemical writings were not simply laboratory notebooks. Many were copied from earlier manuscripts and filled with his own annotations, comparisons, symbols, and experimental notes. In the seventeenth century, the boundary between alchemy and what we now call chemistry was still developing. Newton investigated substances, reactions, metals, and secret processes while also considering ideas such as the philosopher’s stone and the elixir of life.

His interest also helps explain why modern descriptions of Newton as purely a rational physicist are incomplete. He believed ancient thinkers might have concealed important truths in coded language, allegory, and symbolism. Some of his alchemical work was secretive because certain practices were controversial, legally restricted, or potentially heretical.

Much of this material remained unpublished for centuries. In 1936, Newton’s manuscripts were auctioned, and economist John Maynard Keynes acquired a substantial collection of the alchemical papers. Keynes later described Newton as “the last of the magicians,” highlighting how deeply scientific and esoteric interests could coexist in early modern intellectual life.