PEEBLES PROFILES
EPISODE XXX: Fritz Haber
“Father of Chemical Warfare”
FAMILY TIES
Fritz Haber was born in Breslau on December 9, 1868 as part of a well-off Jewish family. The family name Haber was a common one in the area, but Fritz Haber’s family has been traced back to a great-grandfather named Pinkus Selig Haber, a wool dealer from Kempen (now Kępno, Poland). An important Prussian edict of March 13, 1812 determined that Jews and their families (including Pinkus Haber) were “to be treated as local citizens and citizens of Prussia”. Under such regulations, members of the Haber family were able to establish themselves in respected positions in business, politics, and law.
Fritz Haber was the son of first cousins who married in spite of considerable opposition from their families. His father Siegfried was a well-known merchant in the town, who had founded his own business in dye pigments, paints and pharmaceuticals. His mother Paula experienced a difficult pregnancy and died three weeks after Fritz’s birth, leaving Siegfried devastated and young Fritz in the care of various aunts. When Fritz was about six years old, his father married again to Hedwig Hamburger, with whom he had three daughters (Else, Helene and Frieda). Although his relationship with his father was distant and often difficult, Fritz developed close relationships with his step-mother and his half-sisters.
By the time Fritz was born, the Habers had to some extent assimilated into German society. Fritz attended primary school at the Johanneum School, a “simultaneous school” open equally to Catholic, Protestant, and Jewish students. At eleven, he went to school at the St. Elizabeth classical school, in a class evenly divided between Protestant and Jewish students. His family supported the Jewish community and continued to observe many Jewish traditions, but were not strongly associated with the synagogue. Nevertheless, Fritz Haber identified strongly as German, less so as Jewish.
EDUCATION, STUDIES, AND EARLY WORK
He successfully passed his examinations at the St. Elizabeth High School in Breslau in September 1886. Although Siegfried wished him to apprentice in the dye company, Fritz obtained his father’s permission to study chemistry at the Friedrich Wilhelm University in Berlin (today known as the Humboldt University of Berlin) with the director of the Institute for Chemistry, A. W. Hofmann.
Haber was disappointed with his initial winter semester (1886–87), and arranged to attend the Heidelberg University for the summer 1887 semester. There he studied under Robert Bunsen. Fritz then returned to Berlin and entered the Technical College of Charlottenburg (today known as the Technical University of Berlin).
In the summer of 1889, Haber left the university to perform a legally-required year of voluntary service in the Sixth Field Artillery Regiment. Upon his completion, Fritz returned to Charlottenburg where he became a student of Carl Liebermann. In addition to Liebermann’s lectures on organic chemistry, Haber also attended lectures by Otto Witt on the chemical technology of dyes.
Liebermann assigned Haber to work on reactions with piperonal for his thesis topic, published as Ueber einige Derivate des Piperonals (About a Few Piperonal Derivatives) in 1891. Fritz received his doctorate cum laude from Friedrich Wilhelm University in May of that year, after presenting his work to a board of examiners from the University of Berlin. Charlottenburg was not yet accredited to grant doctorate degrees.
Fritz then returned to Breslau to work at his father’s chemical business. Sadly, the father and son did not get along well. Through Siegfried’s connections, Fritz was assigned a series of practical apprenticeships in different chemical companies to gain experience. These included Grünwald and Company (in Budapest, Hungary), an Austrian ammonia-sodium factory, and the Feldmühle paper and cellulose works. Based on these experiences, Haber realized that he needed to learn more about technical processes. So Fritz persuaded his father to let him spend a semester at Polytechnic College in Zürich (today known as the Swiss Federal Institute of Technology), studying with Georg Lunge.
In the autumn of 1892, Haber returned again to Breslau to work in his father’s company. But again, the two men continued to clash, and Siegfried finally accepted that he and his son could no longer work together.
Fritz Haber then sought an academic appointment, first working as an independent assistant to Ludwig Knorr at the University of Jena between 1892 and 1894. During that time, Haber converted from Judaism to Lutheranism, possibly in an attempt to improve his chances of getting a better academic or military position. Knorr then recommended Haber to Carl Engler, a chemistry professor at the University of Karlsruhe who was intensely interested in the chemical technology of dye, the dye industry itself, and the study of synthetic materials for textiles. Engler then referred Haber to a colleague in Karlsruhe, Hans Bunte, who made Fritz an assistant in 1894.
Bunte suggested that Fritz examine the thermal decomposition of hydrocarbons. By making careful quantitative analyses, Haber was able to establish that “the thermal stability of the carbon-carbon bond is greater than that of the carbon-hydrogen bond in aromatic compounds and smaller in aliphatic compounds”, a classic result in the study of pyrolysis of hydrocarbons. This work became Haber’s habilitation thesis.
Haber was appointed Privatdozent in Bunte’s institute, taking on teaching duties related to the area of dye technology, and continuing to work on the combustion of gases. In 1896, the university supported Fritz in traveling to Silesia, Saxony, and Austria to learn about advances in dye technology.
One year later, Haber made a similar trip to learn about developments in electrochemistry. Fritz had been interested in the area for some time, and he had worked with another Privatdozent, Hans Luggin, who gave theoretical lectures in electrochemistry and physical chemistry.
Fritz Haber’s 1898 book, Grundriss der Technischen Elektrochemie auf Theoretischer Grundlage (Outline of Technical Electrochemistry Based on Theoretical Foundations), attracted considerable attention… in particular, his work on the reduction of nitrobenzene. In the book’s foreword, Fritz expressed his gratitude to Luggin, who died on December 5, 1899. Haber also collaborated with others in the area, including Georg Bredig, a student and later an assistant of Wilhelm Ostwald in Leipzig.
Bunte and Engler supported an application for further authorization of Haber’s teaching activities. On December 6, 1898, Fritz was invested with the title of Extraordinarius and an associate professorship, by order of the Grand Duke Friedrich von Baden.
Haber worked in a variety of areas while at Karlsruhe, making significant contributions in several areas. In the area of dye and textiles, he and Friedrich Bran were able to theoretically explain steps in textile printing processes developed by Adolf Holz. Discussions with Carl Engler prompted Haber to explain autoxidation in electrochemical terms, differentiating between dry and wet autoxidation. Fritz’s examinations of the thermodynamics of the reaction of solids confirmed that Faraday’s laws hold for the electrolysis of crystalline salts. This work led to a theoretical basis for the glass electrode and the measurement of electrolytic potentials. Haber’s work on irreversible and reversible forms of electrochemical reduction are considered classics in the field of electrochemistry. He also studied the passivity of non-rare metals and the effects of electric current on corrosion of metals. In addition, Haber published his second book, Thermodynamik Technischer Gasreaktionen : Sieben Vorlesungen (1905), translated in English as Thermodynamics of Technical Gas Reactions: Seven Lectures (1905). It was later regarded as “a model of accuracy and critical insight” in the field of chemical thermodynamics.
In 1906, Max Le Blanc, chair of the physical chemistry department at Karlsruhe, accepted a position at the University of Leipzig. After receiving recommendations from a search committee, the Ministry of Education in Baden offered the full professorship for physical chemistry at Karlsruhe to Fritz Haber, who promptly accepted the offer.
NOBEL PRIZE
During his time at University of Karlsruhe from 1894 to 1911, Fritz Haber and his assistant Robert Le Rossignol invented the Haber–Bosch process, which is the catalytic formation of ammonia from hydrogen and atmospheric nitrogen under conditions of high temperature and pressure. This discovery was a direct consequence of Le Châtelier’s principle, announced in 1884, which states that when a system is in equilibrium and one of the factors affecting it is changed, the system will respond by minimizing the effect of the change. Since it was known how to decompose ammonia on nickel based catalyst, one could derive from Le Châtelier’s principle that the reaction could be reversed to produce ammonia at high temperature and pressure (a process that Henry Louis Le Châtelier had even tried himself but gave up after his technician almost killed himself, due to an oxygen intake related explosion).
To further develop the process for large-scale ammonia production, Haber turned to industry. Teaming with Carl Bosch at BASF, the process was successfully scaled up to produce commercial quantities of ammonia. The Haber–Bosch process was a milestone in industrial chemistry.
The production of nitrogen-based products such as fertilizer and chemical feedstocks, previously dependent on acquisition of ammonia from limited natural deposits, now became possible using an easily available, abundant base: atmospheric nitrogen. The ability to produce much larger quantities of nitrogen-based fertilizers in turn supported much greater agricultural yields and prevented billions of people from starving to death.
The discovery of a new way of producing ammonia had other significant economic impacts as well. Chile had been a major (and almost unique) producer of natural deposits such as sodium nitrate (caliche). After the introduction of the Haber process, naturally extracted nitrate production in Chile fell from two and a half million tons (employing 60,000 workers and selling at $45 per ton) in 1925 to just 800,000 tons (produced by 14,133 workers and selling at $19 per ton) in 1934.
The annual world production of synthetic nitrogen fertilizer is currently more than one hundred million tons. The food base of half of the current world population is based on the Haber–Bosch process.
As a result, Fritz Haber was awarded the 1918 Nobel Prize in Chemistry for this work (he actually received the award one year later).
He was also active in the research on combustion reactions, the separation of gold from sea water, adsorption effects, electrochemistry, and free radical research. A large part of Haber’s work from 1911 to 1933 was done at the Kaiser Wilhelm Institute for Physical Chemistry and Electrochemistry at Berlin-Dahlem. In 1953, this institute was renamed in honor of Fritz Haber. He is sometimes credited (albeit incorrectly) with first synthesizing MDMA (which was first synthesized by Merck KGaA chemist Anton Köllisch in 1912).
BIRTH OF CHEMICAL WARFARE
Haber greeted the First World War with enthusiasm, joining ninety-two other German intellectuals in signing the Manifesto of the Ninety-Three in October 1914. He played a major role in the development of the non-ballistic use of chemical warfare in World War I, in spite of the proscription of their use in shells by the Hague Convention of 1907 (to which Germany was a signatory). He was promoted to the rank of captain and made head of the Chemistry Section in the Ministry of War soon after the war began.
In addition to leading the teams developing chlorine, phosgene, mustard, and other deadly gases for use in trench warfare, Haber was personally on hand when the nicknamed “Green Cross” was first released by the German military at the Second Battle of Ypres, fought from April 22 to May 25, 1915 in Belgium. He also helped to develop gas masks with adsorbent filters for added protection.
A special unit was formed for gas warfare (Pioneer Regiments 35 and 36) under the command of Otto Peterson, with Fritz Haber and Friedrich Kerschbaum as advisors. Haber actively recruited physicists, chemists, and other scientists to be transferred to the unit. Future Nobel laureates James Franck, Gustav Hertz, and Otto Hahn served as gas troops. In the months before the Second Battle of Ypres, Haber’s unit investigated reports that the French had deployed Turpenite (a supposed chemical weapon) against German soldiers.
Gas warfare in World War I was, in a sense, the war of the chemists, with Fritz Haber pitted against French Nobel laureate chemist Victor Grignard. Regarding war and peace, Haber once said,
“During peace time, a scientist belongs to the world, but during wartime, he belongs to his country.”
This was an example of the ethical dilemmas facing chemists at that time. Haber was a patriotic German who was proud of his service during the Great War, for which he was decorated. He was even given the rank of captain by the Kaiser, which Haber had been denied twenty-five years earlier during his compulsory military service.
In his studies of the effects of poison gas, Haber noted that exposure to a low concentration of a poisonous gas for a long time often had the same effect as exposure to a high concentration for a short time. He formulated a simple mathematical relationship between the gas concentration and the necessary exposure time. This relationship became known as Haber’s rule.
Fritz defended gas warfare against accusations that it was inhumane, saying that death was death, by whatever means it was inflicted. During the 1920s, scientists working at his institute developed the cyanide gas formulation, Zyklon A, which was used as an insecticide, especially as a fumigant in grain stores.
POST-WAR DISCOVERIES
Haber also received much criticism for his involvement in the development of chemical weapons in pre-World War II Germany, both from contemporaries and from modern-day scientists. From 1919 to 1923, he continued to be involved in Germany’s secret development of chemical weapons, working with Hugo Stoltzenberg and helping both Spain and Russia in the development of chemical gases.
From 1919 to 1925, in response to a request made by the German ambassador to Japan, Wilhelm Solf, for Japanese support for German scholars in times of financial hardship, a Japanese businessman named Hoshi Hajime, the president of Hoshi Pharmaceutical Company, donated two million Reichsmarks to the Kaiser Wilhelm Society as the ‘Japan Fund’ (Hoshi-Ausschuss). Haber was asked to manage the fund, and he was invited by Hoshi to Japan in 1924. Fritz offered a number of chemical licenses to Hoshi’s company, but they were refused. The money from that fund was used to support the work of Richard Willstätter, Max Planck, Otto Hahn, Leo Szilard, and others.
In the 1920s, Haber searched exhaustively for a method to extract gold from sea water. He published a number of scientific papers on the subject. After years of research, Fritz concluded that the concentration of gold dissolved in sea water was much lower than those reported by earlier researchers, and that gold extraction from sea water was not economical.
By 1931, Fritz Haber was increasingly concerned about the rise of National Socialism in Germany, along with the possible safety of his friends, associates, and family. Under the Law for the Restoration of the Professional Civil Service of April 7, 1933, Jewish scientists at the Kaiser Wilhelm Society were particular targets. The Zeitschrift für die Gesamte Naturwissenschaft (“Journal for All Natural Sciences”) charged the following:
“The founding of the Kaiser Wilhelm Institute in Dahlem was the prelude to an influx of Jews into the physical sciences. The directorship of the Kaiser Wilhelm Institute for Physical and Electrochemistry was given to the Jew, F. Haber, the nephew of the big-time Jewish profiteer Koppel”.
Although he was not related to Koppel, Haber was stunned by these developments, since he assumed that his conversion to Christianity and his services to the state during World War I should have made him a German patriot. Ordered to dismiss all Jewish personnel, Haber attempted to delay their departure long enough to find them other employment.
On April 30, 1933, Fritz Haber wrote to Bernhard Rust (the national and Prussian minister of education) and Max Planck (president of the Kaiser Wilhelm Society) to tender his resignation as the director of the Kaiser Wilhelm Institute, and as a professor at the university, effective October 1933. Haber said that since he was a converted Jew, he might be legally entitled to remain in his position. But in the end, he no longer wished to do so…
Haber also urged that his children by Charlotte Nathan (who were at boarding school) should leave Germany. Charlotte and the children moved to the United Kingdom around 1933 or 1934. After the end of the Second World War, Charlotte’s children became British citizens.
DEATH
Fritz Haber left Dahlem in August 1933, staying briefly in Paris, Spain, and Switzerland. In the meantime, some of the scientists who had been Haber’s counterparts and competitors in England during the Great War now helped him and others to leave Germany. Brigadier Harold Hartley, Sir William Jackson Pope, and Frederick G. Donnan arranged for Fritz Haber to be officially invited to Cambridge, England. There with his assistant Joseph Joshua Weiss, Haber lived and worked for a few months. Scientists such as Ernest Rutherford were less forgiving of Haber’s involvement in poison gas warfare; he pointedly refused to shake Fritz’s hand!
In 1933, during Haber’s brief sojourn in England, Chaim Weizmann offered him the directorship at the Sieff Research Institute (now the Weizmann Institute) in Rehovot, in Mandatory Palestine. He accepted, and left for the Middle East in January 1934, travelling with his half-sister, Else Haber Freyhahn. Fritz’s ill health overpowered him… and on January 29, 1934, he died of heart failure, mid-journey, in a hotel in Basel, Switzerland. He was sixty-five years old.
