Otto Wallach was born on March 27, 1847, in Königsberg, in East Prussia (Königsberg is now called Kaliningrad and is part of the reorganized former Soviet Union). Wallach's mother was Otillia Thoma Wallach; his father, Gerhard Wallach, was an official in the Prussian government. In school, Wallach became fascinated with chemistry and the history of art, and pursued both interests throughout his life. Early in 1867, he entered the University of Göttingen and received his doctorate in chemistry in 1869.

Wallach's doctoral dissertation was on isomers of toluene. Isomers (iso means same; mer means parts) are substances with identical composition, but different arrangements of the parts, giving the substances different physical and chemical properties. Toluene is one of the products of distillation of coal, and among its many uses is as a solvent in the preparation of fragrances. Wallach's doctoral studies were to provide the background...