This essay focuses on light and theories of combustion in the late 18th century. But it does so “on the nitrogen side”: that is, on the side of those inert three-quarters of air that do not contribute to respiration and, therefore, do not trigger the light-emitting response of phosphorus in experiments. In analyzing the variety of opinions broadly (and imprecisely) ascribable to the “Lavoisierian-Phlogistonist” dispute, this book sheds special light on the non-Lavoisierian German context where Johann Friedrich August Göttling performed his tests on phosphorus and nitrogen – and, subsequently, on Lazzaro Spallanzani’s crucial role in the debate. The book pays attention to theories, but it also deals with experimental practice. Therefore, it tells a story of procedures and instruments: in fact, it was especially on this tricky field that the understanding of the phosphorus-nitrogen relationship was achieved. In reading these pages, we shall meet the great heroes of early chemistry as well as the “artisans of innovation” who gave substantial contributions to the advancement of their discipline: a rich fresco that gives us a clear idea of the complexity of the methodological debate at the turn of the century, and of how widespread scientific activity was at that time.

This book is included in DOAB.