In 1863, Louis Pasteur (1822-1895) was commissioned by Emperor Napoleon III of France (1808-1873) to research the conditions under which wine is converted to vinegar. The result of this work was incorporated into this volume, which recapitulates Pasteur’s landmark study of fermentation in wine and the development of micro-organisms; Pasteur proved that alcohol in wine is oxidized via acetaldehyde to acetic acid by the presence of a microscopic fungus (Mycoderma aceti), then known as “mother of vinegar.” This work by Pasteur became the foundation of the modern science of fermentation and bacteriology. The work includes a dedication to Napoleon III and many illustrations. The volume's frontmatter and select illustrations have been digitized.