When he wasn't helping to establish modern physics (or getting bonked on the head by apples), Sir Isaac Newton devoted himself to uncovering the secrets of the "philosopher's stone"—a mythical concoction that was said to turn lead into gold. In fact, Newton wrote more than 1 million words about alchemy (the "science" of transforming substances into different substances) during his lifetime, National Geographic reports. Soon, images of one of those manuscripts will be available online, thanks to the Chemical Heritage Foundation. The foundation bought the 17th century manuscript, which had been in a private collection for decades, in February. It contains Newton's handwritten copy of a fellow alchemist's (the Harvard-educated George Starkey) recipe for "sophick mercury," which was thought to be an essential element for making the philosopher's stone, Fox News reports.
"Now considered nothing more than mystical pseudoscience," according to the Washington Post, alchemy was once a legitimate scientific pursuit. During Newton's time, it was commonly believed that metals were comprised of multiple compounds, which could be changed to turn one metal into another. It was around the time of Newton's death in 1727, Atlas Obscura notes, that scientists separated chemistry from alchemy. A curator of rare books tells Fox that the manuscript is significant because "it helps us understand Newton’s alchemical reading—especially of his favorite author—and gives us evidence of one more of his laboratory procedure." On the back of the manuscript, according to reports, Newton jotted down unrelated notes on the distillation of iron ore.