In The History and Adventures of an Atom, a London haberdasher relates extraordinary tales of ancient Japan as dictated to him by an omniscient atom that has lived within the bodies of great figures of state. Intended “for the instruction of British ministers,” the work is a savage allegory of England during the Seven Years’ War (1756-1763), draping kings and politicians, domestic and foreign affairs in an intricately detailed, endlessly allusive veil of satire. Lacing his commentary with vitriol, Tobias Smollett gives fantastic expression in the Atom to many of the concerns voiced in his historical and political writings. He creates from the details of Japanese history an ingenious catalog of English places and personalities—from the up-start ruler “Taycho,” whose graspings for power resemble William Pitt’s, to a god of war called “Fatzman” who suggests the grotesquely obese Duke of Cumberland. Smollett also draws on the imagery of the period’s scurrilous political cartoons and injects into his satire a Rabelaisian humor that makes this work perhaps the most scatological in English literature. Edited and introduced by Robert Adams Day, this edition of the Atom is the first to appear since 1926 and the first ever to provide a carefully prepared text, a full apparatus of historical annotations, and an accurate key to personages and places. Day establishes the authorship and the long-disputed work, placing it within the context of Smollett’s writings and opinions, his times and literary world.