Like Charles Seife s Zero and Dava Sobel s Longitude, this passionate intellectual history is the story of the intersection of science and the human, in this case the rivals who discovered oxygen in the late 1700s. That breakthrough changed the world as radically as those of Newton and Darwin but was at first eclipsed by revolution and reaction. In chronicling the triumph and ruin of the English freethinker Joseph Priestley and the French nobleman Antoine Lavoisier-the former exiled, the latter executed on the guillotine-A World on Fire illustrates the perilous place of science in an age of unreason.