Language is the most essential medium of scientific activity. Many historians, sociologists and science studies scholars have investigated scientific language for this reason, but only few have examined those cases where language itself has become an object of scientific discussion. Over the centuries scientists have sought to control, refine and engineer language for various epistemological, communicative and nationalistic purposes. This book seeks to explore cases in the history of science in which questions or concerns with language have bubbled to the surface in scientific discourse. This opens a window into the particular ways in which scientists have conceived of and construed language as the central medium of their activity across different cultural contexts and places, and the clashes and tensions that have manifested their many attempts to engineer it to both preserve and enrich its function. The subject of language draws out many topics that have mostly been neglected in the history of science, such as the connection between the emergence of national languages and the development of science within national settings, and allows us to connect together historical episodes from many understudied cultural and linguistic venues such as Eastern European and medieval Hebrew science.