Fritz Haber

Haber was born in Breslau, Kingdom of Prussia (now Wrocław, Poland), into a well-off Jewish family. Though Haber was a common family name in Breslau, the family has been traced back to a great-grandfather, Pinkus Selig Haber, who was a wool dealer from Kempen (now Kępno, Poland). An important Prussian edict of 13 March 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.

Haber was the son of Siegfried and Paula Haber, who were first cousins who married in spite of considerable opposition from their families. Haber's father Siegfried was a well-known merchant in the town, who had founded his own business in dye pigments, paints and pharmaceuticals. Paula experienced a difficult pregnancy and died three weeks after Fritz's birth, leaving Siegfried devastated and Fritz in the care of various aunts. When Haber was about six years old, Siegfried remarried to Hedwig Hamburger. Siegfried and his second wife had three daughters: Else, Helene, and Frieda. Although his relationship with his father was distant and often difficult owing to Fritz being associated with the death of his first wife, Haber developed close relationships with his stepmother and his half-sisters. Siegfried displayed love and care for his three daughters but never fully accepted Fritz as his son.

By the time Fritz was born, the Habers had to some extent become assimilated into German society. He attended primary school at the Johanneum School, a "simultaneous school" open equally to Catholic, Protestant, and Jewish students. At age 11, he went to school at the St Elizabeth classical school in Breslau, 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. Haber identified strongly as German, less so as Jewish.

Haber successfully passed his examinations at the St Elizabeth gymnasium in September 1886. Although his father wished him to become an apprentice in the dye company, Haber obtained his father's permission to study chemistry at the Friedrich Wilhelm University in Berlin (today the Humboldt University of Berlin), with the director of the Institute for Chemistry A. W. Hofmann. Haber was disappointed by his initial winter semester (1886–87) in Berlin, and arranged to attend Heidelberg University for the summer semester of 1887, where he studied under Robert Bunsen. He then returned to Berlin, to the Technische Hochschule in Charlottenburg (today Technische Universität Berlin).

In the summer of 1889, Haber was conscripted and left university to perform his one-year volunteer service in the Sixth Field Artillery Regiment. Upon its completion, he 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. Haber received his doctorate cum laude from Friedrich Wilhelm University in May 1891, after presenting his work to a board of examiners from the University of Berlin, since Charlottenburg was not yet accredited to grant doctorates.

With his degree, Haber returned to Breslau to work at his father's chemical business, where their relationship continued to have difficulties. Through Siegfried's connections, Haber was assigned a series of practical apprenticeships in different chemical companies to gain experience. These included Grünwald and Company (a Budapest distillery), an Austrian ammonia-sodium factory, and the Feldmühle paper and cellulose works. These experiences drove Haber to learn more about technical processes, and persuaded his father to let him spend a semester at the Polytechnic College in Zürich (now the ETH Zürich), studying with Georg Lunge. In the Fall of 1892, Haber returned again to Breslau to work in his father's company, but the two men continued to clash and Siegfried finally accepted that they could not work well together.

Haber had received a PhD in chemistry by this time, but his father required him to take handwriting courses and become a salesman to learn more about the company. Haber urged his father to transfer from natural to synthetic dyes, but his father refused. Eventually, his father followed global business trends and switched to synthetic dyes. Haber's next suggestion, during a cholera epidemic, was for his father to purchase calcium hypochlorite, which at the time was the only known method for the prevention of cholera. That epidemic ended up being isolated and resulted in their possession of a sizeable amount of unused calcium hypochlorite, which is unstable. This caused a rift between Siegfried and Haber, with his father telling him to go back to his university studies as he did not belong in the business world.

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 his time in Jena, Haber converted from Judaism to Lutheranism, possibly in an attempt to improve his chances of getting a better academic or military position. Knorr recommended Haber to Carl Engler, a chemistry professor at the University of Karlsruhe who was intensely interested in the chemical technology of dyes and the dye industry, and the study of synthetic materials for textiles. Engler referred Haber to a colleague in Karlsruhe, Hans Bunte, who made Haber an Assistent in 1894.

Bunte suggested that Haber 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 a 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 him in travelling to Silesia, Saxony, and Austria to learn about advances in dye technology.

In 1897 Haber made a similar trip to learn about developments in electrochemistry. He had been interested in the area for some time, and had worked with another privatdozent, Hans Luggin, who gave theoretical lectures in electrochemistry and physical chemistry. Haber's 1898 book Grundriss der technischen Elektrochemie auf theoretischer Grundlage (Outline of technical electrochemistry based on theoretical foundations) attracted considerable attention, particularly his work on the reduction of nitrobenzene. In the book's foreword, Haber expresses his gratitude to Luggin, who died on 5 December 1899. Haber collaborated with others in the area as well, 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, and on 6 December 1898, Haber 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 explain theoretically 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. Haber'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) trans. Thermodynamics of technical gas-reactions: seven lectures (1908), 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 Haber, who accepted the offer.

Haber met Clara Immerwahr in Breslau in 1889, while he was serving his required year in the military. Clara was the daughter of a chemist who owned a sugar factory, and was the first woman to earn a PhD (in chemistry) at the University of Breslau. She converted from Judaism to Christianity in 1897, several years before she and Haber became engaged. They were married on 3 August 1901; their son Hermann was born on 1 June 1902.

Clara was a women's rights activist and according to some accounts, a pacifist. Intelligent and a perfectionist, she became increasingly depressed after her marriage and the resulting loss of her career. On 2 May 1915, following an argument with Haber, Clara died of suicide in their garden by shooting herself in the heart with his service revolver. She did not die immediately, and was found by her 12-year-old son, Hermann, who had heard the shot.

The reasons for her suicide remain the subject of speculation. There were multiple stresses in the marriage, and it has been suggested that she opposed Haber's work in chemical warfare. According to this view, her suicide was in part a response to Haber's having personally overseen the first successful use of chlorine gas during the Second Battle of Ypres, resulting in over 67,000 casualties. Haber left within days for the Eastern Front to oversee gas release against the Russian Army. Originally buried in Dahlem, Clara's remains were later transferred at her husband's request to Basel, where she is buried next to him.

Haber married his second wife, Charlotte Nathan, on 25 October 1917 in Berlin. When out travelling, Fritz was staying at the Adlon Hotel which was near the Deutscher Klub. At this establishment, Fritz met Nathan, who was one of the secretaries and sparked his interest with her accomplishments despite not having extensive experience or education. On the day that he met her, it had been raining and she gave him an umbrella to use to which he replied "I lay the umbrella into your arms and myself and my thanks at your feet". She replied "I'd rather like the contrary". They began seeing each other and he would soon propose to her. Charlotte rejected the proposal at first due to their large age difference but she eventually agreed. Charlotte, like Clara, converted from Judaism to Christianity before marrying Haber. The couple had two children, Eva-Charlotte and Ludwig Fritz ("Lutz"). Again, however, there were conflicts, and the couple were divorced as of 6 December 1927.

Haber and Clara's son, Hermann Haber, lived in France until 1941, but was unable to obtain French citizenship. When Germany invaded France during World War II, Hermann and his wife and three daughters escaped internment on a French ship travelling from Marseilles to the Caribbean. From there, they obtained visas allowing them to immigrate to the United States. Hermann's wife Margarethe died after the end of the war, and Hermann committed suicide in 1946. His oldest daughter, Claire, committed suicide in 1949; also a chemist, she had been told her research into an antidote for the effects of chlorine gas was being set aside, as work on the atomic bomb was taking precedence.

Fritz Haber's other son, Ludwig Fritz Haber (1921–2004), became an eminent British economist and wrote a history of chemical warfare in World War I, The Poisonous Cloud (1986). Hermann's daughter Eva lived in Kenya for many years, returning to England in the 1950s. She died in 2015, leaving three children, five grandchildren, and eight great-grandchildren. Several members of Haber's extended family died in Nazi concentration camps, including his half-sister Frieda's daughter, Hilde Glücksmann, her husband, and their two children.