Portrait of Clara Immerwahr (Jewish Women’s Archive)

Portrait of Clara Immerwahr (Jewish Women’s Archive)

Clara Immerwahr

JUNE 21, 2019

Scientist of the Day - Clara Immerwahr

Clara Immerwahr, a German physical chemist, was born on June 21, 1870 to a middle-class Jewish family outside of Breslau (present-day Wrocław, Poland). Her father had studied chemistry but was unable to pursue an academic career due to his religious background. Instead, he became a successful merchant, who was able to hire a tutor to support his daughter’s education at a nearby women’s college. Clara demonstrated an aptitude for science and dreamed of pursuing an advanced degree at the University of Breslau. At the time, German law prevented women from enrolling in college courses, but in 1896 she received permission to start attending lectures as a guest auditor.

Over the next year, Immerwahr supplemented classes in experimental physics and inorganic chemistry with private lessons in order to pass an examination that served as an equivalent of a diploma from a Gymnasium (secondary school). These credentials were sufficient to secure her admission to the university as a full-fledged student rather than an observer. Under the supervision of chemist Richard Abegg, Immerwahr began exploring the solubility and electrochemical behavior of salts containing heavy metals such as mercury, copper, lead, cadmium, and zinc. These investigations formed the basis for her doctoral research, which she successfully defended in December 1900. Immerwahr was the first woman to earn a doctorate from the University of Breslau, and she published several articles based on her research in major German chemistry journals (second image).

After earning her degree, Immerwahr continued working in her advisor’s laboratory. While there she became reacquainted with an old friend who shared her passion for science, Fritz Haber (third image). The two grew up together in Breslau’s Jewish community, although both eventually converted to Christianity to circumvent restrictive anti-Semitic policies. They had attended dance classes together as teenagers but had fallen out of touch. By 1901, Haber was a rising star in the world of physical chemistry. He invited Immerwahr to attend an electrochemistry conference in Freiburg and shortly thereafter they became engaged.

Following their wedding, the Habers relocated to Karlsruhe, where Fritz was employed as a professor. The coming years would be extraordinarily productive for Haber, culminating in his successful synthesis of ammonia from nitrogen and hydrogen gas. (Haber would win the Nobel Prize in Chemistry for this accomplishment in 1918.) For Immerwahr, however, marriage largely marked the end of her career in chemistry. While she occasionally visited her husband’s laboratory and reviewed drafts of his publications, most of her time was occupied with managing their household and caring for their son. She disliked playing the role of a professor’s wife and became increasingly depressed as her husband’s professional star continued to rise.

In 1911, Haber was named the director of the newly-established Kaiser Wilhelm Institute for Physical Chemistry. Immerwahr followed her husband to Berlin, where her feelings of isolation continued to fester, particularly after the outbreak of the Great War in 1914. The German government turned to Haber to expand the production of ammonia for use in fertilizers and munitions, and the chemist’s long hours strained an already tense domestic situation. According to some sources, Immerwahr was also upset with Haber’s later efforts to produce shells filled with poisonous chlorine gas for use on the front lines. The German army deployed these new weapons in April 1915. The following month, Immerwahr took her husband’s military revolver in her garden and shot herself (fourth image).

It is difficult to identify the factors that contributed to Clara Immerwahr’s suicide. She left no note or diaries behind, and Haber did not discuss the details of their relationship for the remainder of his life. A few of their acquaintances suggested that her death was intended as a protest against the corruption of science toward militaristic ends. The extent to which such sentiments outweighed her preexisting feelings of depression or the frustration associated with giving up her career in chemistry must remain a mystery.

Nevertheless, in death Immerwahr has become a symbolic figure among antiwar activists and organizations promoting greater participation by women in science. Her story has been featured in stage plays, television programs, and multiple films, and she is the namesake of awards presented by the German section of the IPPNW (International Physicians for the Prevention of Nuclear War) and UniCat (an interdisciplinary network devoted to catalysis research). These works serve as fitting tributes to a life, and a scientific career, that were both tragically cut short.

Benjamin Gross, Vice President for Research and Scholarship, Linda Hall Library. Comments or corrections are welcome; please direct to grossb@lindahall.org.