From the Archives

1868: The Man Behind Chemical Weapons Is Born

Fritz Haber’s chemical genius was responsible for both fertilizers and chemical weapons. He also developed Zyklon-B for Germany.

This story was originally published on December 9, 2014.

December 9, 1868, is the birthday of Fritz Haber, the Jewish-German chemist whose experimental discoveries were directly responsible for the development of both fertilizers and chemical weapons. His work allowed for the synthesis of ammonia, the key component of the fertilizers that drove the 20th century’s “green revolution,” and earned him the Nobel Prize in Chemistry in 1918. Yet Haber also played a key role not only in introducing poison gases to the battlefields of World War I, but also in developing Zyklon B, the pesticide and disinfectant the Third Reich used to kill millions of Jews during the Holocaust.

Fritz Haber was born in Breslau, Prussia (today, Wroclaw, Poland), to Paula and Siegfried Haber. Siegfried was a successful importer of dyes and pharmaceuticals; Paula died shortly after Fritz’s birth. Siegfried remarried when Fritz was six, and he grew up with three stepsisters.

The family observed some Jewish traditions but was not strongly religious. Haber went to a Protestant high school; half the students in his class were Jewish. He converted to Lutheranism in 1894; each of his two wives were also Jewish converts to Protestantism.

With an eye to joining his father’s business Haber studied chemistry at the universities of Heidelberg and Berlin, as well as the Technical College of Charlottenburg, between periods of working in the industry. The two did not get along well, and after earning a doctorate in organic chemistry in 1891 Haber pursued an academic career, albeit one emphasizing practical research.

Haber became a full professor at Karlsruhe University in 1906. In 1911 he was appointed the first director of Berlin’s Kaiser Wilhelm Institute for Physical Chemistry and Electrochemistry, where he remained until 1933. In 1953 the institute was renamed in his honor.

Working at Karlsruhe University from 1894 to 1911, Haber and chemist Carl Bosch developed what came to be known as the Haber-Bosch process: the formation of ammonia from hydrogen and atmospheric nitrogen under high pressure and temperature, key to making fertilizers and chemical weapons.

During World War I, Haber headed up the German war ministry’s chemical warfare division, overseeing the development of phosgene, chlorine gas and dichlorethyl chloride (mustard gas) and their introduction onto the battlefields of both France and Russia.

Shortly after the first successful use of chlorine, at Ypres, France, in April 1915, Haber’s wife, Clara Immerwahr, who also held a Ph.D. in chemistry, shot herself to death in their garden, possibly in anguish over his work.

After World War I Haber fled to Switzerland to escape prosecution for war crimes. He returned to the Kaiser Wilhelm Institute when the Allies, who had also used chemical weapons, dropped the charges. He continued working on the secret development of poison gases, sometimes in cooperation with Russia and Spain. These included the cyanide-based Zyklon B, which Germany later used in Nazi-era death camps. Haber had already died in exile by then.

But in April 1933, as head of the Kaiser Wilhelm Institute, Haber had to fire a dozen of his Jewish employees under the Law for the Restoration of the Professional Civil Service. He did his best to find them jobs abroad first, and on April 30 he resigned.

Haber was offered a number of positions abroad, including at Rehovot’s Daniel Sieff Institute, now the Weizmann Institute of Science. But before he could travel to Palestine he died of a heart attack, at a hotel in Basel, Switzerland on January 29, 1934.

“At the end,” wrote Haber’s friend and colleague Albert Einstein, in a letter to Haber’s son Hermann, “he was forced to experience all the bitterness of being abandoned by the people of his circle, a circle that mattered very much to him, even though he recognized its dubious acts of violence.”