A Berlin childhood among scientists and writers
Johann Friedrich Wilhelm Adolf Baeyer was born in Berlin on October 31, 1835. He came, as his Nobel biography puts it, from a family distinguished in both literature and the natural sciences. His father, Johann Jacob Baeyer, was a Prussian army officer and geodesist who later rose to lieutenant-general and devised the European system of geodetic measurement, the careful surveying of the shape of the earth. His mother, Eugenie, was the daughter of the Berlin jurist and literary figure Julius Eduard Hitzig. The poet Adelbert von Chamisso and the astronomer Friedrich Wilhelm Bessel stood as the boy’s godparents.
The household was large, with several brothers and sisters, and it was struck by tragedy early. In 1843, when Adolf was seven, his mother died giving birth to a daughter. He was drawn to experiment almost as soon as he could read. As a boy he grew plants on his grandfather’s farm outside Berlin to see how they fed, and he began doing chemistry at home at about nine. At twelve he made a compound no one had described before, a double carbonate of copper and sodium. On his thirteenth birthday he spent his money on a lump of indigo, the deep blue dye of blue cloth, so that he could experiment with it. That small purchase pointed to the work of his life.
Training under Bunsen and Kekulé
After finishing school at Berlin’s Friedrich Wilhelm Gymnasium, where his chemistry teacher had made him his assistant, Baeyer entered the University of Berlin in 1853 to study physics and mathematics. A spell of service in the Prussian army interrupted him, and by 1856 his old love of chemistry had won out. He went to Heidelberg to study with Robert Bunsen, one of the great experimenters of the age, but soon moved to the private laboratory of August Kekulé, whose new theory of how carbon atoms join into chains was transforming organic chemistry.
Kekulé’s structural thinking shaped everything Baeyer did afterwards. He took his doctorate at Berlin in 1858 with a study of arsenic-containing compounds done in Kekulé’s laboratory, and then followed Kekulé to the University of Ghent in Belgium. In 1860 he qualified as a university teacher with a study of uric acid, the compound behind gout, and in the same year became a lecturer at the Gewerbe-Akademie, Berlin’s trade academy. The pay was poor, but he was given a spacious laboratory. In 1866, on the suggestion of the chemist August Wilhelm von Hofmann, the University of Berlin gave him a senior lectureship, but that post was unpaid too. For years Baeyer did world-class research on very little money, sustained by curiosity and a well-equipped bench. It was in these lean Berlin years that Baeyer began most of the research that made his name.
The long chase after indigo
For thousands of years indigo came from plants, above all from the indigo fields of India. It was prized for its beauty and its fastness, and Europe paid a heavy annual price for it. Making it in a laboratory from cheap starting materials was one of the great prizes of nineteenth-century chemistry, and also one of the hardest problems, because no one knew how its atoms were arranged.
Baeyer began work on indigo in 1865. The research led him first to indole, a ring-shaped molecule at the heart of indigo, which he made and whose correct formula he proposed in 1869. Over the next fifteen years, after moving to the new University of Strasbourg in 1871 and then succeeding the famous Justus von Liebig as professor of chemistry at Munich in 1875, he worked out several complete routes to indigo. The Swedish Academy later described three, starting from different nitrogen-containing compounds of benzene. By 1883 he had determined indigo’s chemical structure. It was painstaking work, done step by step, with no lucky accident to shorten it.
From a test tube to the world’s clothing
Baeyer’s own routes were too costly for factories, and it took years of further work by industrial chemists to make synthetic indigo pay. The first commercial product went on sale from the German firm BASF in 1897, made by a process developed by Karl Heumann that built on Baeyer’s foundations. The effect was dramatic. When Baeyer received his Nobel Prize in 1905, the president of the Swedish Academy noted that the price of indigo had already fallen to a third of its former level, and that Germany’s exports of synthetic indigo were worth more than 25 million marks a year. Indigo became a cheap, pure, reliable dye available to everyone.
That shift is still visible today. The blue of ordinary denim jeans comes almost entirely from synthetic indigo, made by descendants of the chemistry Baeyer pioneered. His work on other dyes mattered too. In Berlin his students Carl Graebe and Carl Liebermann, using a technique Baeyer had developed, worked out the structure of alizarin, the red of the madder plant, and an industrial synthesis followed. In Strasbourg he discovered the phthaleins, a family of brilliantly coloured compounds that includes phenolphthalein, long familiar as a chemical indicator, and fluorescein, a strongly glowing dye. In 1872 he also experimented with phenol and formaldehyde, producing a resin that foreshadowed Leo Baekeland’s Bakelite, the first fully synthetic plastic.
Barbituric acid and the medicines that followed
Baeyer’s early study of uric acid had a second, quieter consequence. In the course of it he discovered barbituric acid, first described in 1864. Barbituric acid itself has no sedative effect, but it is the parent compound of the barbiturates, a large family of drugs that other chemists later built from it. For much of the twentieth century barbiturates were the main medicines doctors had for sleep, anaesthesia and seizures.
They also proved dangerous. Barbiturates are easy to overdose on and can cause dependence, and for most uses they were later replaced by safer drugs. But some members of the family remain important medicines, notably in the treatment of epilepsy, and the story of their rise and fall became a lesson in drug safety. The thread of that story begins in Baeyer’s laboratory.
The great teacher of Munich
At Munich Baeyer built an excellent new chemical laboratory and stayed for the rest of his career. His interests ranged across almost the whole of organic chemistry: acetylene and its compounds, the structure of benzene, the chemistry of terpenes, organic peroxides and the link between a molecule’s structure and its colour. In 1885 he proposed his strain theory, which explained why rings of carbon atoms with too few or too many members are less stable than others. With his student Victor Villiger he discovered a reaction, the Baeyer–Villiger oxidation, that chemists still use daily to insert oxygen into molecules. His system for naming certain ring-shaped compounds was later built into the international rules of chemical nomenclature.
He was above all a builder of people. His Nobel biography records that his school alone trained some fifty future university teachers, and his laboratory was one of the places where modern organic chemistry was learned. He was cautious about theory and devoted to careful observation, and even at seventy he worked, in the words of the Nobel Foundation, with a youthful buoyancy. On his fiftieth birthday in 1885 King Ludwig II of Bavaria raised him to the hereditary nobility, which is why he became Adolf von Baeyer.
Jewish heritage
Baeyer’s Jewish roots ran through his mother. Eugenie Hitzig belonged to the Itzig family, one of the leading Jewish families of Berlin. Her father, Julius Eduard Hitzig, had been born into that family and had converted to Christianity; Eugenie herself had become a Christian before marrying Baeyer’s father, who was not of Jewish descent. Both parents were Lutherans when Adolf was born, and he was raised in the Lutheran church.
Baeyer did not identify as Jewish, and there is no record of him practising Judaism. His family story is a typical one for nineteenth-century Germany, where many Jewish families converted in the hope of full acceptance in professional and public life. The Encyclopaedia Judaica includes him among Jewish scientists on the strength of his maternal ancestry, and he is generally counted among the Nobel laureates of Jewish descent.
Family, final years and legacy
In 1868 Baeyer married Adelheid (Lida) Bendemann, the daughter of a family friend. They had three children. Their daughter Eugenie married the chemist Oskar Piloty; their sons Hans and Otto both became university lecturers, Hans in medicine at Munich and Otto in physics at Berlin. Baeyer kept teaching and experimenting almost to the end. He died at his country house on the Starnberger See, south of Munich, on August 20, 1917, at the age of 81.
His honours were many, among them the Royal Society’s Davy Medal in 1881 for his work on indigo and the Nobel Prize in Chemistry in 1905, awarded for his services to organic chemistry and the chemical industry through his work on dyes and ring compounds. The German Chemical Society has given the Adolf von Baeyer Medal since 1911, and a crater on the moon bears his name. His deeper legacy is in ordinary things: the cheap blue dye in the world’s clothing, reactions that chemists still use to build medicines, and a generation of students who carried his careful, experimental way of working into laboratories and factories everywhere.
Sources & further reading
Adolf von Baeyer, Biographical, NobelPrize.org · Award ceremony speech, Nobel Prize in Chemistry 1905, NobelPrize.org · Adolf von Baeyer, Jewish Virtual Library (Encyclopaedia Judaica) · Adolf von Baeyer, Wikipedia · Researched from the sources above and checked against them. Spotted an error? Tell us.
A life of tikkun olam. This is part of tikkun olam, the Jewish idea of repairing the world, and every one of us can add to it.