Since the Enlightenment, alchemy has been viewed as a sort of antiscience, disparaged by many historians as a form of lunacy that impeded the development of rational chemistry. But this book exposes the speciousness of these views and challenges widely held beliefs about the origins of the scientific revolution. Tracing the alchemical roots of Robert Boyle's famous mechanical philosophy, the book shows that alchemy contributed to the mechanization of nature, a movement that lay at the very heart of scientific discovery. Boyle and his predecessors—figures like the mysterious medieval Geber or the Lutheran professor Daniel Sennert—provided convincing experimental proof that matter is made up of enduring particles at the microlevel. At the same time, the book argues that alchemists created the operational criterion of an “atomic” element as the last point of analysis, thereby contributing a key feature to the development of later chemistry.