While the end of the nineteenth century is often associated with the rise of objectivity and its ideal of a restrained observer, scientific experiments continued to create emotional, even theatrical, relationships between scientist and his subject. On Flinching focuses on moments in which scientific observers flinched from sudden noises, winced at the sight of an animal's pain or cringed when he was caught looking, as ways to consider a distinctive motif of passionate and gestured looking in the laboratory and beyond. It was not their laboratory machines who these scientific observers most...