IN 1460, ONE OF MANY book-hunting monks in the employ of the great Cosimo de Medici returned to Florence from a monastery in Macedonia with a nearly complete manuscript of the Hermes Trismegistus’s Corpus Hermeticum. Cosimo (who was already 70 years old, and knew he was close to death) eagerly gave it to his translator, Marsilio Ficino, hoping to be able to read it before he died. At the time, the Corpus Hermeticum appeared, Ficino had been preparing a translation of Plato, but Cosimo ordered Ficino to set the Greek aside and turn to the Corpus Hermeticum instead. Ficino’s translation would in turn develop a life beyond his patron; in the next 150 years, it would go through 16 editions and spread like wildfire through the early modern world.

So far, this story may sound a bit like the opening of The Swerve: How the World Became Modern, in which Stephen Greenblatt tells of another book-hunter, Poggio Bracciolini, whose lucky find of a manuscript of Lucretius’ mystical epic On the Nature of Things revolutionized the Renaissance and “made the world modern.” But Hermes Trismegistus, then as now, lacked the credibility of Lucretius. He was and remains a mythical figure: no historical record of an actual person named “Hermes Trismegistus” exists, nor is it clear who actually authored the various books attributed to him. Additionally, those books — consisting of several dozen texts on astronomy, magic, and philosophy from the fourth century A.D. — hold little interest for 21st century scientists or philosophers. But Hermes Trismegistus was important for another reason: he was credited by many as being the founder of alchemy.

Alchemy runs alongside the traditional narrative of Western thought like a shadow. Long ignored, often discredited as pseudoscience, it has nonetheless had important effects on the cultures of Europe and the Middle East for the past two thousand (or more) years. It’s always been a hermetic field of inquiry, sealed off from mainstream intellectual pursuits, but its traces linger. The phrase “hermetically sealed,” after all, derives from the “Seal of Hermes,” the nickname for the stopper on the long-necked glass jar used in making the Philosopher’s Stone (the substance that would allow for a direct transmutation of an impure metal like lead into the pure silver or gold). We have alchemists to thank for the French name for a double boiler, the bain-marie (bagno-maria in Italian) — a reference to another apocryphal alchemist, Maria the Jew, and her method of heating slowly using water — and for the fact that we refer to quicksilver as “mercury.”

Beyond this, not much of alchemy remains in our modern culture, and what we do know is often wrong. The comic scene in Sterne’s Tristam Shandy, where the protagonist’s father tries to name his son “Trismegistus” only to have the name miscommunicated and reduced to “Tristam” by a forgetful maid and an arrogant priest, offers as good a metaphor as any for the inconsistent transmission of the history of alchemy and its secrets through the ages.

The goal of Lawrence M. Principe’s The Secrets of Alchemy is to begin to retrace that history. Principe, a professor at Johns Hopkins, has been writing on alchemy for years; his latest is a distillation, as it were, of years of academic scholarship into a more generally ...