The discovery of oxygen in the late 1700s changed human thought and history as radically as Newton's falling apple, Darwin's theory of evolution, and Einstein's calculations of mass and energy. Its isolation formed the basis of modern chemistry, led to the identification of the elements, and paved the way for modem atomic physics. Its discovery began quietly - with the survival of a lab mouse - and its denouement was violent - the ruin and exile of one discoverer, Joseph Priestley, to America, and the execution of the other, Antoine Lavoisier, at the guillotine.
It is a story of a seismic change in science, accompanied by and connected to earthquakes in the political realm - the waning days of the Enlightenment, the storming of the Bastille, and the American Revolution. By their actions and thoughts inside and outside the laboratory, Lavoisier and Priestley helped usher in the modern age.