Cultural historian McCalman (editor, An Oxford Companion to the Romantic Age) presents an enlightening account of the career of one of the most famous charlatans of the 18th century, Count Alessandro di Cagliostro. He was born poor, in 1743, in Sicily, where he began his career as a petty street thug. Setting the pattern for the rest of his life, Cagliostro was forced to flee Sicily after defrauding a local merchant. He traveled all over Europe, usually one step ahead of the authorities, spreading his brand of Freemasonry and billing himself as an alchemist and healer. Tremendously charismatic, he gained legions of followers. In Russia, he tried to convert Catherine the Great to Freemasonry, but she viewed him as politically subversive and harried him out of the country. Cagliostro's journeys finally brought him to Italy, where he was hounded as a fake by the newspapers. The amorous adventurer Casanova described Cagliostro as a fraud who fleeced the gullible. While in Italy, his wife, Seraphina, grew tired of all the traveling and the constant bad publicity, and betrayed him to the Inquisition, which, shocked by his Freemasonry and his claims to have supernatural powers, sentenced him to life in prison; he died there in 1795. McCalman's account is adeptly researched and written with a light, charming touch; as the author makes abundantly clear, the Age of Reason was also an age of mysticism and downright quackery. 26 b&w illus. (June 6)