Richard Willstätter

Working out what chlorophyll and flower pigments are made of (1905-1914)

• Testing more than 200 kinds of plants, he showed that all green plants share the same two chlorophylls, a and b, in a ratio of roughly three to one.^[3],[5],[7]
• He proved that magnesium is an essential part of chlorophyll, not an impurity, and showed its chemical kinship with heme, the red pigment in blood.^[3],[4],[7]
• His groundwork laid the base for Hans Fischer's Nobel Prize-winning work on the structures of heme and chlorophyll (1930); Robert Woodward later synthesized chlorophyll.^{[6],[7],[14],[16]}
• His 1915 gas-mask filter, which used activated charcoal and a compound called hexamethylenetetramine, protected soldiers from chlorine and phosgene; about 30 million were in use by 1917.^[5],[6],[7]
• He trained Richard Kuhn, who won the 1938 Nobel Prize in Chemistry, and Arthur Stoll, who later led the drug company Sandoz in Basel.^[5],[15]

We make no quantified claims for Willstätter. His prize-winning work was fundamental chemistry: it established what chlorophyll and flower pigments are, and it became the base for Hans Fischer's structure of chlorophyll and, later, Robert Woodward's synthesis of it. Knowledge like this reaches plant science, food and medicine only through long chains of later work, and any number we attached to it would be invented. His most concrete practical contribution, the 1915 gas-mask filter, protected soldiers from chlorine and phosgene, and about 30 million were in use by 1917, but we found no reliable count of lives it saved. Smaller legacies include the anaesthetic Avertin, a wood-to-sugar process later scaled up by Friedrich Bergius, and adsorption methods for purifying enzymes that later researchers found useful. His largest multiplier may have been people: he trained chemists such as Richard Kuhn, who won the 1938 Nobel Prize, and Arthur Stoll, who later led the drug company Sandoz.

Fundamental scienceHealth

No number is given here on purpose. Some contributions cannot be counted honestly, and we would rather describe them than invent a figure.

• Minor

  Signing the 1914 'Manifesto of the Ninety-Three'

  In autumn 1914 he signed the 'To the Civilized World' manifesto of 93 German scholars and artists. It denied German responsibility for the war and denied that German troops had wronged Belgian civilians except in self-defense. His Neue Deutsche Biographie entry notes that he later partly distanced himself from it in his autobiography.^[5],[12]

• Minor

  Gas-mask work inside Germany's chemical-warfare effort

  At Haber's request he designed a three-layer gas-mask filter in 1915, and in 1917 he received the Iron Cross (Second Class) for it. The filter protected soldiers, but it was developed within the war research that Haber, who promoted the use of chlorine gas, directed; chemical weapons killed more than 90,000 soldiers in World War I.^{[5],[6],[7],[9],[13]}

• Minor

  A wrong theory of enzymes

  He held that enzymes were small molecules riding on larger carrier particles rather than proteins themselves, and he doubted James Sumner's 1926 claim to have crystallized the enzyme urease as a protein. Some of his students kept defending his idea into the 1930s; it was abandoned once pepsin and other enzymes were also crystallized and shown to be proteins.^[5],[7]

• 1883

  Discrimination

  When his father left for New York and his mother moved the family to Nuremberg, the boy met more open antisemitism there than he had known in Karlsruhe.^[7]

• —

  Discrimination

  Baeyer advised him to be baptized, a step that would have removed barriers Jewish scholars faced; he refused. He later wrote that professing Jews had been held back in many parts of the state service, contrary to the constitution, long before 1933.^[7],[8],[9]

• 1924

  Discrimination

  With posters in Munich declaring that no German youth should sit at the feet of a Jewish teacher, and after his faculty voted against the Jewish geochemist Victor Goldschmidt, he resigned his chair in protest in June 1924 and never set foot in the laboratory again.^{[2],[6],[7],[8],[9]}

• 1933

  Dismissal

  After the Nazis took power and threatened to boycott Sandoz products, the company pressed him in April 1933 to step down as chairman of the supervisory board of its Nuremberg subsidiary.^[5]

• 1938

  Persecution

  On 10 November 1938, the day after Kristallnacht, Gestapo officers came to his Munich house to take him to the Dachau concentration camp. He was not at home; they searched the house and said they would return.^{[5],[8],[9],[11]}

• 1939

  Exile

  To obtain a passport he had to sign away his villa and other assets, and an attempt to row across Lake Constance without papers ended in his brief arrest. He reached Switzerland in March 1939, leaving his library and Nobel medal behind.^{[5],[6],[8],[9]}

Both parents came from long-established Jewish families. His father's family had lived in Karlsruhe since about 1720; his great-grandfather Elias served as acting rabbi there, and a relative, Benjamin Willstätter, was a Karlsruhe rabbi. His mother's family, the Ulmanns of Fürth, can be traced to Augsburg in 1585. Willstätter never converted, and he refused Adolf von Baeyer's advice to be baptized. He treated religion as a private matter and said his belief was close to Einstein's 'God of Spinoza', but unlike his friend Fritz Haber he always openly acknowledged his Jewish origin.^{[5],[7],[8],[9]}

1. August 13, 1872

   Born in Karlsruhe, Baden, into a Jewish merchant family; his father Max is a cloth merchant.^[1],[5]

2. May 17, 1894

   Earns his doctorate at the University of Munich under Alfred Einhorn, having entered in 1890 and come under Adolf von Baeyer's influence.^[2],[6],[7]

3. 1898

   Works out the structure of the local anaesthetic cocaine, which he later confirms by synthesis.^[5],[7]

4. 1905

   Becomes professor of chemistry at the Federal Polytechnic (now ETH) in Zurich and begins his main work on chlorophyll.^[2],[5]

5. 1908

   His wife, Sophie Leser, dies after a delayed operation for appendicitis, leaving him with two young children.^[5],[7]

6. October 1912

   Takes up the post of head of organic chemistry at the new Kaiser Wilhelm Institute for Chemistry in Berlin-Dahlem, next door to Fritz Haber's institute.^[2],[7],[10]

7. 1915

   His 10-year-old son Ludwig dies in the spring, apparently of diabetes.^[5],[7]

8. 1915

   At Haber's request, designs a three-layer gas-mask filter; about 30 million are in use by 1917, the year he receives the Iron Cross (Second Class) for it.^[5],[6],[7]

9. November 11, 1915

   Awarded the Nobel Prize in Chemistry for his research on plant pigments, especially chlorophyll; because of the war he lectures in Stockholm only in June 1920.^[1],[3],[10]

10. April 1, 1916

    Succeeds his teacher Adolf von Baeyer as professor of chemistry at the University of Munich.^[2],[6]

11. June 24, 1924

    Asks to resign his professorship in protest after the faculty votes against the Jewish geochemist Victor Goldschmidt; he leaves the post in 1925.^{[2],[6],[7],[9]}

12. November 10, 1938

    The day after Kristallnacht, Gestapo officers come to his Munich home to take him to Dachau; he is not there.^[5],[8],[9]

13. March 1939

    Emigrates to Switzerland after losing most of his property, and settles in Muralto, near Locarno.^[5],[6],[9]

14. August 3, 1942

    Dies of a heart attack in Muralto, having written his memoirs, published in 1949 as Aus meinem Leben.^[1],[2]

1. 1.Richard Willstätter - Facts · NobelPrize.org (Nobel Prize Outreach)
2. 2.Richard Willstätter - Biographical · NobelPrize.org (from Nobel Lectures, Chemistry 1901-1921, Elsevier, 1966), 1966
3. 3.On Plant Pigments (Nobel Lecture, 3 June 1920) · NobelPrize.org, 1920
4. 4.Speed read: Revealing plant's colour complexity · NobelPrize.org, 2009
5. 5.Willstätter, Richard Martin (by Adam Vollmer), Neue Deutsche Biographie 28, pp. 199-201 · Deutsche Biographie (Historical Commission, Bavarian Academy of Sciences), 2024
6. 6.Richard Willstätter - Kurzbiographie (written for the LMU Munich professors' catalogue), by Freddy Litten · litten.de, 2000
7. 7.Richard Willstätter (Encyclopedia of World Biography) and Willstätter, Richard (Dictionary of Scientific Biography, by J.S. Fruton) · Encyclopedia.com (Gale)
8. 8.Richard Willstätter (Meilensteine series), by Jan Björn Potthast · Deutsches Patent- und Markenamt (German Patent and Trade Mark Office), 2022
9. 9.Mahnmale, Gedenkstätten, Erinnerungsorte für die Opfer des Nationalsozialismus in München 1933-1945, Band 3, by Helga Pfoertner (Willstätter entry, pp. 158-166) · NS-Dokumentationszentrum München (archived by the Internet Archive), 2005
10. 10.Chronik des Kaiser-Wilhelm-/Max-Planck-Instituts für Chemie · Max Planck Institute for Chemistry
11. 11.Kristallnacht · United States Holocaust Memorial Museum, Holocaust Encyclopedia
12. 12.Manifesto of the Ninety-Three · Wikipedia
13. 13.History · Organisation for the Prohibition of Chemical Weapons (OPCW)
14. 14.Hans Fischer - Facts · NobelPrize.org
15. 15.Richard Kuhn - Biographical · NobelPrize.org
16. 16.Robert B. Woodward - Facts · NobelPrize.org