Gotta get that philosopher’s stone. (Photo: Chemical Heritage Foundation)

Isaac Newton didn’t believe in magic, but he did believe in the philosopher’s stone, a legendary concoction that could turn lead to gold.

In Newton’s time, chemistry had not been developed, and alchemy was a perfectly respectable pursuit for a scientist. Newton was a devotee and studied the combination of strange substances as avidly as he did physics. (If you’ve read Neal Stephenson’s Quicksilver, none of this is news to you.)

Recently, the Chemical Heritage Foundation acquired a document that showed just how deep he got into alchemy. The document includes Newton’s handwritten copy of a recipe for sophick mercury, the key ingredient to the philosopher’s stone.

The recipe for “Preparation of Mercury for the Stone” came from George Starkey, a Harvard scientist and leading alchemist. As the Washington Post notes, Newton probably had access to this recipe before Starkey published it: he was in the inner circle of alchemists.

Newton lived from 1642 to 1727; the discovery of elements and gases like hydrogen and carbon dioxide and the theory of atoms came decades after his death. Alchemy wasn’t all bad: around the time of Newton’s death, scientists started making a distinction between chemistry—basically, the useful, scientific threads of mixing chemicals together—and alchemy, the more mystical parts.

Alchemy, naturally, got the “turning lead into gold” part of the practice: they never did figure out how to make that one work.

Bonus finds: A skull.

Every day, we highlight one newly found object, curiosity or wonder. Discover something amazing? Tell us about it! Send your finds to sarah.laskow@atlasobscura.com.