Alchemy has traditionally been viewed as 'the history of an error', an example of mediaeval gullibility and greed, in which alchemists tried to turn lead into gold, create fabulous wealth and find the elixir of life. But alchemy has also been described as 'the mightiest secret that a man can possess', and it obsessed the likes of Isaac Newton, Robert Boyle and many of the founders of modern science. This book explores its history, from its mysterious beginnings in Egypt and China, through the Hellenistic world and the early years of Islam and into mediaeval Europe.