The category of ‘permanently elastic fluids’, which by the late eighteenth century was widely used by investigators of pneumatic phenomena, embodies key aspects of the history of air as it gradually turned into a chemical species and a physical state of matter. In this talk, I explore the evolution of early conceptions of Air in terms of fluidity, elasticity, and material activity. I examine the interplay between theory and practice from early mechanistic depictions of Air, through Boyle’s use of the notion of ‘springiness’, to the emergence of various conceptions of fluids, including aerial ones, based on the work of Boyle, Newton, and their contemporaries. Mobilizing new accounts of elastic fluids, in the early 1700s pneumatic practitioners drew analogies between Air and Fire. In the 1720s–30s, following Stephen Hales’s experimental demonstration that air could be fixed in and obtained from solid and liquid substances, natural philosophers and chemists introduced further distinctions between atmospheric Air and views of air as an active material agent and a form of matter. By the middle of the century, increasingly prevalent references to permanently elastic fluids marked the culmination of these developments. This reading challenges and complements the accepted narrative of the rise of pneumatic chemistry as essentially driven by a series of landmark experiments, facilitated by technological innovations ranging from the air pump to the pneumatic trough.
Promotion & Tenure Seminar - Co-sponsored by the School of Physics and Astronomy