As the authors show, the writings of medieval alchemists may seem like the ravings of brain-addled fools, but there is more to the story than that. Recent scholarship has shown that some seemingly nonsensical mysticism is, in fact, decipherable code, and Western European alchemists functioned from a firmer theoretical foundation than previously thought. They had a guiding principle, based on experience: separate and purify materials by fire and reconstitute them into products, including, of course, gold and the universal elixir, the Philosophers' stone. Their efforts were not in vain: by trial, by error, by design, and by persistence, the alchemists discovered acids, alkalis, alcohols, salts, and exquisite, powerful, and vibrant reactions--which can be reproduced using common products, minerals, and metals.