From a rabbinic family in Karlsruhe
Richard Martin Willstätter was born on 13 August 1872 in Karlsruhe, in the Grand Duchy of Baden, into a Jewish family with deep local roots. Among his ancestors were rabbis of Karlsruhe, including his great-great-grandfather, Rabbi Ephraim Willstätter. His father, Max Willstätter, was a textile merchant, and his mother was Sophie Ulmann. Baden had granted its Jews full civic equality in 1862, a decade before his birth, and families like his thought of themselves as thoroughly German. His parents expected him to go into the family business, but by about the age of twelve he had set his heart on science.
He went to the Gymnasium in Karlsruhe and, after the family moved to Nuremberg, to the technical school there. The Nuremberg school now bears his name: since 1965 it has been the Willstätter-Gymnasium.
Munich and a quarrel over cocaine
In 1890, aged eighteen, Willstätter entered the University of Munich to study chemistry, drawn by the great organic chemist Adolf von Baeyer. He stayed for fifteen years. He did his doctorate under Alfred Einhorn on the structure of cocaine, completing it in 1894, and by the time he finished he had evidence that his own supervisor’s proposed structure was wrong. Einhorn was offended and barred him from further work on cocaine, but Willstätter went on to work out the structures of cocaine and related alkaloids such as atropine and to synthesise several of them.
His range was wide. He also worked on quinones and on the chemistry of aniline black, a dye, and he synthesised cyclooctatetraene, a ring of eight carbon atoms, showing that it does not behave like benzene, an important test of chemists’ ideas about why some ring compounds are unusually stable. He became a lecturer in 1896 and an associate professor in 1902. Baeyer, who valued him highly, once suggested that he convert to Christianity to smooth his academic path, as many German Jews of his generation did. Willstätter refused. In 1903 he married Sophie Leser; they had a son, Ludwig, born in 1904, and a daughter, Margarete, born in 1906. In 1908 Sophie died after a delayed operation for appendicitis, leaving him a widower at 35.
The green of leaves
In 1905 Willstätter became professor at the Federal Institute of Technology (ETH) in Zurich, where he spent seven productive years and began the work that made him famous: the chemistry of chlorophyll, the green pigment that allows plants to capture the energy of sunlight. Chlorophyll is fragile and hard to purify, and earlier chemists had produced contradictory results. Using painstaking new methods of extraction and separation, Willstätter determined its composition and showed that magnesium is an essential part of the molecule, bound at its centre much as iron is in haemoglobin, the red pigment of blood.
He examined chlorophyll from more than two hundred plant species and found it to be essentially the same everywhere: a mixture of two closely related compounds, which he named chlorophyll a and chlorophyll b, in a ratio of roughly three to one. He also made important early progress on the carotenoids, the yellow and orange pigments of carrots and egg yolk. This work laid the chemical foundations for the later understanding of photosynthesis, the process on which nearly all life on Earth depends.
Berlin, flowers and the Nobel Prize
In 1912 he moved to Berlin as professor at the university and director of a department at the new Kaiser Wilhelm Institute for Chemistry in Dahlem, where his neighbours included Fritz Haber, who became a close friend. There he turned to the pigments of flowers and fruit, the anthocyanins. He identified the main compounds, cyanidin, pelargonidin and delphinidin, responsible for many reds, blues and purples, and showed that the colour of a flower depends heavily on the acidity or alkalinity of the plant’s sap.
In 1915 he was awarded the Nobel Prize in Chemistry “for his researches on plant pigments, especially chlorophyll.” Because of the First World War, he gave his Nobel lecture, On Plant Pigments, in Stockholm only in June 1920.
War work: the gas mask
When the war came, Haber, himself of Jewish birth, led Germany’s poison gas programme, which launched the first large-scale chlorine attack near Ypres in April 1915, and he asked Willstätter to join it. Willstätter would not work on poisons, but he agreed to work on protection. With his colleagues he developed a three-layer filter for gas masks that absorbed the enemy’s gases; by 1917 some thirty million had been made. He received the Iron Cross for the work.
The war also brought private grief. His son Ludwig died in 1915, apparently of diabetes, at the age of about eleven. In 1916 Willstätter returned to Munich as Baeyer’s successor in the chair of chemistry, one of the most prestigious posts in German science.
Enzymes
After the war he turned to enzymes, the molecules that speed up chemical reactions in living things. He developed methods to purify them and did much to establish that enzymes are chemical substances that can be studied with the tools of chemistry, rather than mysterious properties of living cells. Some of the enzymatic reactions his laboratory studied produced useful drugs, including the anaesthetic tribromoethanol.
He was wrong about one central point: he argued that enzymes were small active molecules carried on larger, inert supports, and to the end of his life he refused to accept that enzymes are themselves proteins, which American chemists such as James Sumner went on to show. Even so, his work is counted among the foundations of modern biochemistry, and many of his students became leading chemists. Among them were Arthur Stoll, his collaborator on chlorophyll, who went on to build up pharmaceutical research at Sandoz in Basel, and Richard Kuhn, who took his doctorate under Willstätter in Munich in 1922 and won the Nobel Prize in Chemistry in 1938.
A protest against antisemitism
In the early 1920s antisemitism was rising in Munich, among students and in the university itself. The breaking point came in 1924, when Willstätter put forward the eminent geochemist Victor Moritz Goldschmidt, who was of Jewish descent, for a chair of mineralogy. As Willstätter later recalled, the faculty by a large majority declined to nominate the only famous scholar on the list because they did not want a scholar of presumably Jewish descent among them. He announced his resignation the same evening.
Students, colleagues and the Bavarian minister begged him to stay. The psychiatrist Emil Kraepelin remarked that he should have stayed and thrown the others out instead. Willstätter told the dean that his decision was final, left the university in 1925, refused tempting offers from Germany and abroad, and carried on research privately from his house in Munich, his assistants reporting their results to him by telephone. He still filed patents as a private scholar in 1928 and 1929. In 1933 he wrote the introduction to Juden im deutschen Kulturbereich, a vast survey of Jewish contributions to German culture commissioned by the Central Association of German Citizens of the Jewish Faith; the Nazi police confiscated the printed copies in 1934.
Escape and exile
Although he was urged to leave Germany after Hitler came to power and was offered a position in Palestine, Willstätter, a German patriot, stayed in Munich. During the November pogrom of 1938 the Gestapo came to his house to take him to the Dachau concentration camp. He happened to be in the garden and was not found. His daughter urged him to go, and with the help of his former student Arthur Stoll, by then a leading chemist at the Sandoz company in Basel, he managed to emigrate, arriving in Switzerland in March 1939.
He had to leave behind nearly everything, his house, his large library, his art collection and even his Nobel medal. He settled in the Villa Eremitaggio at Muralto, near Locarno, and spent his last years writing his memoirs. He died there of heart failure on 3 August 1942, aged 69.
Legacy
Willstätter’s autobiography, Aus meinem Leben, was published in 1949 and appeared in English as From My Life in 1965. It is a valuable first-hand account of German science, and of German-Jewish life, in the first half of the twentieth century.
His memory has been honoured in the places that once shut him out. The Nuremberg school he attended took his name in 1965, and the University of Munich records his protest resignation in its official history. In 2024 a bust of Willstätter was dedicated in Willstätt, the village in Baden whose name his family bore, with his great-granddaughter, the scholar Margarete Feinstein, representing the family.
His chemistry endures in every textbook account of chlorophyll and the pigments of flowers. His resignation endures as a rare example of a leading scientist sacrificing his position on principle, years before most of his colleagues were forced to confront what antisemitism would mean. Proud of both his German culture and his Jewish ancestry, he refused to give up either, and he paid for it with his career, his home and, in the end, his country.
Sources & further reading
Richard Willstätter, Wikipedia · Richard Willstätter, Encyclopedia.com · Richard Willstätter, German Patent and Trade Mark Office (DPMA), Great Inventors · Margarete Feinstein on Family Legacy, Loyola Marymount University · Richard Willstätter, Biographical, NobelPrize.org · Researched from the sources above and checked against them. Spotted an error? Tell us.
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