The Physics of Imponderable Fluids

This article discusses the physics of imponderable, or weightless, fluids. It first reviews the existing historical literature on the physics of imponderables before considering how supporters and sceptics of imponderables reacted after 1800 to the introduction of new instruments of analysis that followed the introduction of the Voltaic battery. The Voltaic battery was followed by the development of an array of new concepts that included sophisticated mathematical tools, unanticipated chemical procedures, and ingenious wood and brass apparatus. The tangled developments accompanying the introduction of these new instruments culminated somehow, after two decades, with the adoption of the notion of electric current. The article also explores the views of Pierre Simon Laplace regarding imponderables and how the new instruments were addressed by three authors: Jean Baptiste Biot, Humphry Davy, and André-Marie Ampère.