A year after writing his famous note to Robert Hooke stating that “if I have seen further, it is by standing on the shoulders of giants,” Isaac Newton sent a far more secretive, and far more surprising, letter. In 1676, Henry Oldenburg was the secretary of the Royal Society, the powerful scientific academy, and as such, had nontrivial power to encourage research. But in this case, Newton wanted to discourage a particular line of research and publication. Specifically, he wanted fellow scientist Robert Boyle to cease writing about the “sophic mercury” that became hot when mixed with gold. Newton’s concern was that this discovery could hasten the public awareness of the famous “philosopher’s stone,” which had the power to turn lead into gold. Discovering the philosopher’s stone was the chief goal of the pseudoscience known both then and now as alchemy.

Perhaps you’re surprised to find that Newton, widely considered the greatest and most important scientist to draw breath, didn’t just laugh at alchemy. Turning lead into gold? Really? Everybody knows that’s a joke. In this case, however, you’re the one standing on the shoulders of scientific giants who succeeded Newton. In the 17th century, alchemy was considered as legitimate a field of inquiry as any other. Newton wrote over a million words on the topic, and although he did not disclose his interest to the public during his lifetime, his discretion was due not to shame but rather concern that he might be abducted and forced to perform alchemy for some wayward aristocrat or warlord.