Skip to content
Nobel Jews
Portrait of Adolf von Baeyer
Photo: Unknown author · Public domain via Wikimedia Commons

Nobel Prize in Chemistry · 1905

Adolf von Baeyer

He worked out how to build indigo in the lab, opening the way to the cheap synthetic blue that colours the world's jeans.

The Nobel citation: “in recognition of his services in the advancement of organic chemistry and the chemical industry, through his work on organic dyes and hydroaromatic compounds”
Born
October 31, 1835, Berlin, Prussia (now Germany)
Died
August 20, 1917, Starnberg, Germany
Affiliation at the time
Munich University, Germany

Chemistry prize

1905

Awarded alone.

Age that year

70years

Born in 1835.

Headline credited impact

$1.1–2.1billion in economic value

Cumulative world sales of synthetic indigo dye, 1897-2025 (a proxy for economic value). How it was built

Sources cited

32

Fact-checked September 24, 2026.

  • At the 1905 ceremony, the Royal Swedish Academy of Sciences' president said indigo now cost a third of its old price; Germany exported over 25 million marks' worth in 1904.
  • World output of plant-grown indigo fell from about 19,000 tons in 1897, the year synthetic indigo went on sale, to about 1,000 tons by 1914.
  • At least four chemists trained in his labs won chemistry Nobels: Emil Fischer (1902), Eduard Buchner (1907), Richard Willstätter (1915) and Heinrich Wieland (1927).
  • Lists of Jewish Nobel laureates count him as the first, through his mother, a great-granddaughter of Daniel Itzig, head of Berlin's Jewish community.
  • He was raised a Protestant, but the Nazis still counted his ancestry: in 1933 his son Hans was dismissed from his Heidelberg professorship as 'non-Aryan'.

The breakthrough

Decoding and building indigo, and advancing the chemistry of dyes and carbon rings

For thousands of years, blue cloth depended on plants. Indigo had to be extracted from leaves, mostly on farms in India, and it was expensive. Baeyer set out to learn what the blue molecule actually was. Starting in 1865, he broke indigo into smaller pieces, identified them, and then tried to put them back together, the way a mechanic learns an engine by taking it apart and rebuilding it. In 1878 he and Adolf Emmerling made indigo from simpler chemicals for the first time. More routes followed in 1880 and, with Viggo Drewsen, in 1882, and in 1883 he proposed the molecule's structure: how its atoms are joined. His own recipes were too costly for factories, but they proved synthetic indigo was possible and showed industry what to aim for. BASF bought his 1880 patent and, using other chemists' cheaper routes, began selling synthetic indigo in 1897. Baeyer did much more. He discovered the phthalein dyes, including fluorescein, which glows green, and phenolphthalein, and showed how small changes in a dye's structure change its colour. He made barbituric acid, the parent compound of barbiturate drugs, and his 'strain theory' helped explain why rings of five or six carbon atoms are far more common than other sizes. The Nobel Prize honoured his dye work and his research on hydroaromatic compounds, ring molecules that bridge the two great families of organic chemistry.[2],[3],[4],[6],[10],[15],[17],[22],[23]

“I have never set up an experiment to see whether I was right, but to see how the materials behave”
Adolf von Baeyer, Baeyer's description of his experimental approach, quoted in English translation in his Nobel Foundation biography (Nobel Lectures, Chemistry 1901-1921).[2]

What it meant for humanity

Before Baeyer, blue cloth came from a labour-hungry plantation economy. In 1897 plants grown on about 7,000 square kilometres, mostly in India, yielded some 19,000 tons of indigo. Synthetic indigo, built on Baeyer's structure and syntheses, went on sale that year. At the 1905 prize ceremony, the president of the Royal Swedish Academy of Sciences reported that the price of indigo had already fallen to a third, and by 1914 plant output was down to about 1,000 tons. Today almost all indigo is synthetic, roughly 50,000 to 80,000 tonnes a year, sold for about 5 US dollars a kilogram, and more than 90% of it dyes denim. The cheap, durable blue of jeans, workwear and uniforms traces back to the chemistry he opened up.

His other discoveries reached medicine. Fluorescein, which he first made in 1871, became a standard tool in eye care: doctors use it to reveal damage to the surface of the eye and, since 1961, to photograph blood flowing through the retina. Barbituric acid, which he made in 1864, became the parent of more than 2,500 barbiturate compounds; about 50 reached patients as sleeping pills, anaesthetics and epilepsy drugs, and a few are still used.

Perhaps his largest legacy was people. His school produced about fifty future university teachers, at least four chemists trained in his laboratories later won Nobel Prizes, and his research and teaching helped build Germany's organic chemical industry.

  • World output of plant-grown indigo fell from about 19,000 tons in 1897 to about 1,000 tons by 1914 as synthetic indigo took over; today roughly 50,000 to 80,000 tonnes a year are made synthetically.[15],[18],[19],[20],[21]
  • At the 1905 prize ceremony, the president of the Royal Swedish Academy of Sciences reported that indigo's price had fallen to a third, with German synthetic indigo exports worth over 25 million marks in 1904.[3]
  • Fluorescein, first made in Baeyer's lab in 1871, is still used to examine the surface of the eye and, since 1961, to image the blood vessels of the retina.[23]
  • Barbituric acid (1864) became the parent of more than 2,500 barbiturates; about 50 were used in patients as sedatives, anaesthetics and epilepsy drugs.[22]
  • Emil Fischer, Eduard Buchner, Richard Willstätter and Heinrich Wieland, all trained in Baeyer's laboratories, won the chemistry Nobel in 1902, 1907, 1915 and 1927.[24],[25],[26],[32]

Impact in numbers

Baeyer's clearest measurable legacy is synthetic indigo. We record its cumulative world sales as a rough proxy for economic value and credit 15% to Baeyer, because the factory processes that made it cheap came from Karl Heumann, Johannes Pfleger and the engineers of BASF and Hoechst. Sales understate the benefit to buyers, who got a cheaper, purer blue, and they ignore the losses of Indian growers. His wider influence cannot honestly be given a number: the phthalein dyes, fluorescein in eye medicine, the chemistry of carbon rings, reactions that bear his name such as the Baeyer-Villiger oxidation, and a school that produced about fifty professors and at least four Nobel laureates. We make no claim for barbiturates, good or bad. Other chemists created the drugs decades after he made the parent compound, and neither their benefits for epilepsy and anaesthesia nor their overdose deaths can be credited to him in any meaningful share.

EconomyFundamental scienceHealth

Each number is the laureate’s credited share of a real-world outcome, cumulative to 2025. The whole outcome, the share of credit, and the reasoning are shown so you can check the arithmetic. Outcomes shared with other laureates are counted once on the impact page.

  • Low confidenceDirectModeledEconomy

    Cumulative world sales of synthetic indigo dye, 1897-2025 (a proxy for economic value)

    $1.1–2.1

    billion in economic value, credited share

    That is 15% of $7–14 billion in economic value since 1897.

    How this number was built

    No published total; sales proxy. Tonnage: ~5,000 t for jeans (1980), ~14,000 t (1988), ~24,000 t (2001) per Kröppl; 50,000 t by 2011 and ~80,000 t/yr by 2023 per Wikipedia; ~50,000 t/yr per Bidart et al. Linear interpolation. Low: 1980-2025 only, flat 50,000 t after 2011 = 1.42M t. High: rise to 80,000 t by 2023 (1.68M t for 1980-2025) plus 1.16M t for 1897-1979 (assumed ramp to 15,000 t by 1907, then flat; likely high mid-century, when newer dyes displaced indigo) = 2.84M t. Price $5/kg (Bidart et al. 2024), held constant, so early decades are undervalued. Low 1.42M t x $5,000/t = $7.1B, rounded to $7B; high 2.84M t x $5,000/t = $14.2B, rounded to $14B. Share 0.15: Baeyer found the structure and first syntheses, but his routes were impractical; Heumann's and Pfleger's routes and BASF/Hoechst engineering made the product.[15],[16],[17],[19],[20],[21]

    Sources: Springer Nature (open access); Wikipedia; National Geographic; Nature Portfolio; BASF (company history); BASF (company history)

The double edge

Baeyer's chemistry had costs he did not choose. Cheap synthetic indigo destroyed a plant-dye economy that covered about 7,000 square kilometres, mostly in India. The crop had long been forced on Indian peasants by European planters, and when prices fell, planters in Champaran, Bihar, pushed their losses onto tenants through higher rents and payments to be released from growing indigo; Gandhi's 1917 campaign there targeted these abuses. Today's synthetic indigo relies on harsh chemicals: dyeing denim uses tens of thousands of tons of reducing agents a year, and researchers link it to polluted rivers and soil and to worker exposure to toxic substances. Barbiturates, descended from the barbituric acid he made in 1864, caused dependence and many overdose deaths before safer drugs replaced most of them, although other chemists, among them his former student Emil Fischer, created those drugs almost 40 years after his discovery. We put no numbers on these harms, because no fair share of them can be attributed to him.

  • Moderate

    Collapse of India's indigo economy and the burden on Champaran's peasants

    Synthetic indigo made the plant crop unprofitable; India's indigo exports fell from Rs 4.75 crore in 1894-95 to Rs 2.96 crore five years later. In Champaran, planters raised tenants' rents by 50-60% and demanded large 'compensation' payments to release them from compulsory indigo growing, abuses that Gandhi's 1917 satyagraha challenged.[18],[29]

  • Moderate

    Pollution from indigo manufacture and denim dyeing

    Indigo must be dissolved with harsh reducing agents in alkaline baths before it can dye cotton. The denim industry uses about 50,000 tons of synthetic indigo and over 84,000 tons of sodium hydrosulfite a year, and researchers link indigo dyeing to polluted waterways and soil, crop losses and human toxicity.[20],[21]

  • Minor

    Barbiturate dependence and overdose deaths

    Barbiturates caused dependence and many overdose deaths; in the UK alone, 12,354 deaths in 1965-1970 were attributed directly to them. Baeyer's link is distant: he made barbituric acid in 1864, but the first sedative barbiturate came from Josef von Mering and Emil Fischer, Baeyer's former student and assistant, in 1903.[22]

Against the odds

Baeyer faced little personal discrimination, and it would be wrong to suggest otherwise. He was born into a Protestant household; his Jewish heritage came through his mother, whose branch of the Itzig family, descended from the Berlin Jewish community leader Daniel Itzig, became Lutheran in 1799. Many ambitious Jews of that era took the same step: according to the 1906 Jewish Encyclopedia, a university career in Prussia was effectively closed to Jews unwilling to be baptized. Jews in the North German Confederation gained formal legal equality only in 1869, and discrimination continued in practice. Baeyer's Christian upbringing spared him these barriers, and he rose from poorly paid and unpaid Berlin teaching posts to Liebig's chair in Munich. His Jewish student Richard Willstätter was less fortunate: he succeeded Baeyer in Munich, then resigned in 1924 in protest at rising antisemitism and fled the Gestapo in 1938. After Baeyer's death, the Nazis treated his ancestry as disqualifying. In 1933 his son Hans, professor of orthopaedics at Heidelberg, was dismissed as 'non-Aryan' because his grandmother Eugenie Hitzig and his maternal grandfather were of Jewish descent. Other descendants lost academic posts and left Germany; his grandson Hans Jakob escaped to Switzerland and later settled in Canada.

  • 1799

    Other

    Baeyer's maternal grandfather's family, a branch of the Jewish Itzig family, became Lutheran in 1799, in an era when a university career in Prussia was effectively closed to Jews unwilling to be baptized; formal legal equality came only in 1869. Baeyer, raised a Protestant, faced no recorded barrier of this kind himself.[7],[11],[27],[28]

  • 1933

    Dismissal

    Sixteen years after Baeyer's death, his son Hans was dismissed from his Heidelberg professorship of orthopaedics as 'non-Aryan', because his paternal grandmother (Baeyer's mother) and his maternal grandfather were of Jewish descent.[13],[14]

  • —

    Exile

    Under Nazi rule the family's Jewish connections led to expulsions from German academic posts and, for many descendants, emigration; Baeyer's grandson Hans Jakob von Baeyer escaped with his family to Switzerland and later moved to Canada.[13]

Jewish background

Jewish motherDistant from Jewish identity

Baeyer's father, the geodesist Johann Jacob Baeyer, was of non-Jewish descent. His mother, Eugenie Hitzig (1807-1843), came from the Itzig family, long prominent among Berlin's Jews: her father, the jurist and author Julius Eduard Hitzig, was born Isaac Elias Itzig, a grandson of Daniel Itzig, head of Berlin's Jewish community. The family had become Lutheran, Eugenie was baptized, and Adolf was raised a Protestant. His wife, Lida Bendemann, also came from a family with Jewish roots. No source shows that he identified as Jewish, but the Nazis counted this ancestry: in 1933 his son Hans was dismissed as 'non-Aryan'.[7],[8],[9],[10],[11],[12],[13],[14],[30],[31]

Key dates

  1. October 31, 1835

    Born in Berlin to the Prussian officer and geodesist Johann Jacob Baeyer and Eugenie, née Hitzig.[1],[2],[8]

  2. 1858

    Earns his doctorate in Berlin for work on cacodyl compounds done in August Kekulé's private laboratory in Heidelberg.[2]

  3. 1860

    Qualifies as a university teacher and starts teaching organic chemistry at Berlin's Trade Academy, where the pay is poor but the laboratory is roomy.[2]

  4. 1864

    Makes barbituric acid, later the parent compound of barbiturate drugs.[6],[22]

  5. 1865

    Starts his long study of indigo, a blue dye that had intrigued him since he was young.[2]

  6. 1872

    Becomes professor at the newly founded university in Strasbourg, where Emil Fischer becomes his student.[6],[7],[24]

  7. 1875

    Succeeds Justus von Liebig as professor of chemistry at the University of Munich and builds a large new laboratory.[2],[6],[7]

  8. 1878

    With Adolf Emmerling, completes the first full laboratory synthesis of indigo.[15],[19]

  9. 1883

    Proposes the chemical structure of indigo.[6],[15]

  10. 1885

    Raised to the hereditary Bavarian nobility on his 50th birthday, gaining the 'von' in his name.[2],[7],[10]

  11. 1897

    BASF, which had bought his indigo patent, launches synthetic indigo using a cheaper route developed from Karl Heumann's work.[16],[17]

  12. 1905

    Wins the Nobel Prize in Chemistry for work on organic dyes and hydroaromatic compounds; illness keeps him from the ceremony, and he gives no Nobel lecture.[1],[3],[5]

  13. August 20, 1917

    Dies at his country house on Lake Starnberg, near Munich, aged 81.[1],[2]

  14. 1933

    The Nazi regime dismisses his son Hans from Heidelberg University as 'non-Aryan' because of the family's Jewish descent.[13],[14]

Sources

  1. 1.Adolf von Baeyer - Facts · NobelPrize.org (Nobel Prize Outreach)
  2. 2.Adolf von Baeyer - Biographical · NobelPrize.org (from Nobel Lectures, Chemistry 1901-1921, Elsevier, 1966), 1966
  3. 3.The Nobel Prize in Chemistry 1905 - Award ceremony speech by A. Lindstedt · NobelPrize.org, 1905
  4. 4.Speed read: The birth of dyeing · NobelPrize.org, 2009
  5. 5.Adolf von Baeyer - Nobel Prize lecture (note: no lecture was delivered) · NobelPrize.org
  6. 6.Adolf von Baeyer · Encyclopaedia Britannica, 2026
  7. 7.Baeyer, Adolf Johann Friedrich Wilhelm Ritter von · Neue Deutsche Biographie 1 (1953), via Deutsche Biographie, 1953
  8. 8.Baeyer, Johann Jakob (by Fritz Mühlig) · Neue Deutsche Biographie 1 (1953), via Deutsche Biographie, 1953
  9. 9.Baeyer, Adolf von (from Encyclopaedia Judaica, 2007) · Jewish Virtual Library (AICE), 2007
  10. 10.Adolf von Baeyer · Wikipedia
  11. 11.Julius Eduard Hitzig · Wikipedia (German)
  12. 12.Daniel Itzig · Wikipedia
  13. 13.Some Family History (von Baeyer family) · Cornelius von Baeyer, vonbaeyer.net, 2020
  14. 14.Hans Ritter von Baeyer · Wikipedia (German)
  15. 15.Indigo: history of its synthesis (M. Kröppl), Monatshefte für Chemie - Chemical Monthly · Springer Nature (open access), 2026
  16. 16.1897 / "Indigo Pure BASF" · BASF (company history)
  17. 17.Cooperative Research - Formula for Success · BASF (company history)
  18. 18.Indigo - The Crop that Created History and then Itself Became History (R. Prasad), Indian Journal of History of Science 53.3 · Indian National Science Academy, 2018
  19. 19.Indigo dye · Wikipedia
  20. 20.Blue jeans are terrible for the environment - but a new discovery could help (O. Ferrari) · National Geographic, 2024
  21. 21.Chemoenzymatic indican for light-driven denim dyeing (Bidart et al.), Nature Communications · Nature Portfolio, 2024
  22. 22.The history of barbiturates a century after their clinical introduction (López-Muñoz, Ucha-Udabe, Alamo), Neuropsychiatric Disease and Treatment · Dove Medical Press, via PubMed Central, 2005
  23. 23.A brief history of fluorescein (V. Naik) · Hektoen International, 2025
  24. 24.Emil Fischer - Biographical · NobelPrize.org
  25. 25.Eduard Buchner - Biographical · NobelPrize.org
  26. 26.Richard Willstätter - Biographical · NobelPrize.org
  27. 27.Universities · Jewish Encyclopedia (1906), JewishEncyclopedia.com, 1906
  28. 28.Law on Freedom of Religion (July 3, 1869) · German History in Documents and Images (German Historical Institute)
  29. 29.Celebrating the Champaran Satyagraha, a Hundred Years On (Irfan Habib) · The Wire, 2017
  30. 30.List of Jewish Nobel laureates · Wikipedia
  31. 31.Itzig family · Wikipedia
  32. 32.Heinrich Wieland - Biographical · NobelPrize.org

Fact-checked on September 24, 2026 by a separate AI fact-checking pass that re-opened the sources, with 11 corrections made. How we check

Suggest a correction