On the Existence of Active Oxygen Thesis Presented for the Attainment of the Degree of Doctor of Philosophy at the Johns Hopkins University

A mid‑19th‑century dissertation takes listeners on a detailed tour of the early chemistry of oxygen, beginning with the startling discovery that a single element can exist in multiple allotropic forms. The author traces how ozone was first isolated, how its unusual density and bleaching power set it apart, and why scientists soon began to wonder whether other, even more reactive versions of oxygen might be hidden in familiar reactions.

Drawing on laboratory notes from Europe and America, the work recounts a series of experiments that on the surface seem simple—mixing barium superoxide with acid, exposing organic liquids to sunlight, or passing electricity through oxygen—but each was meant to catch a fleeting “active” gas in the act. Competing ideas about “nascent,” “antozone,” and free oxygen atoms are presented alongside the rigors of Engler and Nasse’s investigations that challenged earlier assumptions. Listeners will hear the excitement, the debates, and the painstaking method of a time when the very nature of the air itself was still being written.