Abstract

In the late nineteenth century, French naturalists were global leaders in microbial research. Louis Pasteur advanced sterilization techniques and demonstrated that dust particles in the air could contaminate a putrefiable liquid. Pasteur’s discoveries prompted a new research program for the naturalists of the Talisman and Travailleur expeditions: to recover uncontaminated water and mud samples from the deep sea. French naturalists Adrien Certes and Paul Regnard both independently conducted experiments to address the question of whether microorganisms inhabited the oceans and whether organic material in the deep sea was subject to decomposition. The experiments of Certes and Regnard have largely been omitted from histories of microbiology and marine science. However, an examination of their work is crucial for understanding the context in which marine microbiology first developed. At the end of the nineteenth century, marine microbiology emerged from the disciplinary melding of terrestrial microbial ecology, experimental physiology, and the then-nascent field of deep-sea biology.