a long letter to the German military leadership. Fritz Haber attacked him for his essay, accusing him of harming Germany, and Staudinger in turn criticized Haber for his role in the German chemical weapons program. Polymer chemistry While at Karlsruhe and later, Zurich, Staudinger began research in the chemistry of rubber, for which very high molecular weights had been measured by the physical methods of Raoult and van 't Hoff. Contrary to prevailing ideas (see below), Staudinger proposed in a landmark paper published in 1920 that rubber and other polymers such as starch, cellulose and proteins are long chains of short repeating molecular units linked by covalent bonds. In other words, polymers are like chains of paper clips, made up of small constituent parts linked from end to end (Figure 3). At the time, leading organic chemists such as Emil Fischer and Heinrich Wieland believed that the measured high molecular weights were only apparent values caused by the aggregation of small molecules into colloids. At first, the majority of Staudinger’s colleagues refused to accept the possibility that small molecules could link together covalently to form high-molecular weight compounds. As Mülhaupt aptly notes, this is due in part to the fact that molecular structure and bonding theory were not fully understood in the early 20th century. In 1926, he was appointed lecturer of chemistry at the University of Freiburg at Freiburg im Breisgau (Germany), where he spent the rest of his career. In 1927, he married the Latvian botanist, Magda Voita (also shown as; ), who was a collaborator with him until his death and whose contributions he acknowledged in his Nobel Prize acceptance. Further evidence to support his polymer hypothesis emerged in the 1930s. High molecular weights of polymers were confirmed by membrane osmometry, and also by Staudinger’s measurements of viscosity in solution. The X-ray diffraction studies of polymers by Herman Mark provided direct evidence for long chains of repeating molecular units. And the synthetic work led by Carothers demonstrated that polymers such as nylon and polyester could be prepared by well-understood organic reactions. His theory opened up the subject to further development, and helped place polymer science on a sound basis. Private life He married in 1906 to Dora Förster and they remained together until their divorce in 1926. They had four children including Eva Lezzi (1907-1993) and Klar (Klara) Kaufmann who were active in resisting the rise of