Alexander Fleming

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Sir Alexander Fleming

Synthetic Production of Penicillin TR1468.jpg
Alexander Fleming in his laboratory at St Mary's, Paddington, London (1943).
Born(1881-08-06)6 August 1881
Died11 March 1955(1955-03-11) (aged 73)
London, England
Resting placeSt. Paul's Cathedral
Alma mater
Known forDiscovery of penicillin and
Scientific career
FieldsBacteriology, immunology
Alexander Fleming signature.svg

Sir Alexander Fleming FRS FRSE FRCS[1] (6 August 1881 – 11 March 1955) was a Scottish physician and microbiologist. His best-known discoveries are the enzyme lysozyme in 1923 and the world's first broadly effective antibiotic substance benzylpenicillin (Penicillin G) from the mould Penicillium rubens in 1928, for which he shared the Nobel Prize in Physiology or Medicine in 1945 with Howard Florey and Ernst Boris Chain.[3][4][5] He wrote many articles on bacteriology, immunology, and chemotherapy.

Fleming was knighted for his scientific achievements in 1944.[6] In 1999, he was named in Time magazine's list of the 100 Most Important People of the 20th century. In 2002, he was chosen in the BBC's television poll for determining the 100 Greatest Britons, and in 2009, he was also voted third "greatest Scot" in an opinion poll conducted by STV, behind only Robert Burns and William Wallace.

Early life and education

Born on 6 August 1881 at Lochfield farm near Darvel, in Ayrshire, Scotland, Alexander Fleming was the third of four children of farmer Hugh Fleming (1816–1888) and Grace Stirling Morton (1848–1928), the daughter of a neighbouring farmer. Hugh Fleming had four surviving children from his first marriage. He was 59 at the time of his second marriage to Grace, and died when Alexander was seven.[7]

Fleming went to Loudoun Moor School and Darvel School, and earned a two-year scholarship to Kilmarnock Academy before moving to London, where he attended the Royal Polytechnic Institution.[8] After working in a shipping office for four years, the twenty-year-old Alexander Fleming inherited some money from an uncle, John Fleming. His elder brother, Tom, was already a physician and suggested to him that he should follow the same career, and so in 1903, the younger Alexander enrolled at St Mary's Hospital Medical School in Paddington; he qualified with an MBBS degree from the school with distinction in 1906.[7]

Fleming, who was a private in the London Scottish Regiment of the Volunteer Force from 1900[3] to 1914,[9] had been a member of the rifle club at the medical school. The captain of the club, wishing to retain Fleming in the team, suggested that he join the research department at St Mary's, where he became assistant bacteriologist to Sir Almroth Wright, a pioneer in vaccine therapy and immunology. In 1908, he gained a BSc degree with Gold Medal in Bacteriology, and became a lecturer at St Mary's until 1914. Commissioned lieutenant in 1914 and promoted captain in 1917,[9] Fleming served throughout World War I in the Royal Army Medical Corps, and was Mentioned in Dispatches. He and many of his colleagues worked in battlefield hospitals at the Western Front in France. In 1918 he returned to St Mary's Hospital, where he was elected Professor of Bacteriology of the University of London in 1928. In 1951 he was elected the Rector of the University of Edinburgh for a term of three years.[7]


Work before penicillin

During World War I, Fleming witnessed the death of many soldiers from sepsis resulting from infected wounds. Antiseptics, which were used at the time to treat infected wounds, often worsened the injuries.[10] In an article he submitted for the medical journal The Lancet during World War I, Fleming described an ingenious experiment, which he was able to conduct as a result of his own glass blowing skills, in which he explained why antiseptics were killing more soldiers than infection itself during World War I. Antiseptics worked well on the surface, but deep wounds tended to shelter anaerobic bacteria from the antiseptic agent, and antiseptics seemed to remove beneficial agents produced that protected the patients in these cases at least as well as they removed bacteria, and did nothing to remove the bacteria that were out of reach.[11] Sir Almroth Wright strongly supported Fleming's findings, but despite this, most army physicians over the course of the war continued to use antiseptics even in cases where this worsened the condition of the patients.[7]

At St Mary's Hospital Fleming continued his investigations into antibacterial substances. Testing the nasal secretions from a patient with a heavy cold, in 1922 he found that nasal mucus had an inhibitory effect on bacterial growth.[12] This was the first recorded discovery of lysozyme, an enzyme present in many secretions including tears, saliva, skin, hair and nails as well as mucus. Although he was able to obtain larger amounts of lysozyme from egg whites, the enzyme was only effective against small counts of harmless bacteria, and therefore had little therapeutic potential.[10]

Accidental discovery

An advertisement advertising penicillin's "miracle cure".

One sometimes finds, what one is not looking for. When I woke up just after dawn on September 28, 1928, I certainly didn't plan to revolutionize all medicine by discovering the world's first antibiotic, or bacteria killer. But I suppose that was exactly what I did.

— Alexander Fleming[13]

By 1927, Fleming had been investigating the properties of staphylococci. He was already well known from his earlier work, and had developed a reputation as a brilliant researcher. In 1928, he studied the variation of Staphylococcus aureus grown under natural condition, after the work of Joseph Warwick Bigger, who discovered that the bacterium could grow into a variety of types (strains).[14] On 3 September 1928, Fleming returned to his laboratory having spent a holiday with his family at Suffolk. Before leaving for his holiday, he inoculated staphylococci on culture plates and left them on a bench in a corner of his laboratory.[15] On his return, Fleming noticed that one culture was contaminated with a fungus, and that the colonies of staphylococci immediately surrounding the fungus had been destroyed, whereas other staphylococci colonies farther away were normal, famously remarking "That's funny".[16] Fleming showed the contaminated culture to his former assistant Merlin Pryce, who reminded him, "That's how you discovered lysozyme."[17] He identified the mould as being from the genus Penicillium. He suspected it to be P. chrysogenum, but a colleague Charles J. La Touche identified it as P. rubrum. (It was later corrected as P. notatum and then officially accepted as P. chrysogenum; but finally in 2011, it was resolved as P. rubens.)[18][19] The laboratory in which Fleming discovered and tested penicillin is preserved as the Alexander Fleming Laboratory Museum in St. Mary's Hospital, Paddington.

Fleming grew the mould in a pure culture and found that the culture broth contained the antibacterial a substance. He investigated its positive anti-bacterial effect on many organisms, and noticed that it affected bacteria such as staphylococci and many other Gram-positive pathogens that cause scarlet fever, pneumonia, meningitis and diphtheria, but not typhoid fever or paratyphoid fever, which are caused by Gram-negative bacteria, for which he was seeking a cure at the time. It also affected Neisseria gonorrhoeae, which causes gonorrhoea, although this bacterium is Gram-negative. After some months of calling it "mould juice" or "the inhibitor", he named the substance it released penicillin on 7 March 1929.[20]

Fleming published his discovery in 1929, in the British Journal of Experimental Pathology,[21] but little attention was paid to his article. Fleming continued his investigations, but found that cultivating Penicillium was quite difficult, and that after having grown the mould, it was even more difficult to isolate the antibiotic agent. Fleming's impression was that because of the problem of producing it in quantity, and because its action appeared to be rather slow, penicillin would not be important in treating infection. Fleming also became convinced that penicillin would not last long enough in the human body (in vivo) to kill bacteria effectively. Many clinical tests were inconclusive, probably because it had been used as a surface antiseptic. In the 1930s, Fleming's trials occasionally showed more promise,[22] but Fleming largely abandoned penicillin work, leaving Howard Florey and Ernst Boris Chain at the Radcliffe Infirmary in Oxford to take up research to mass-produce it, with funds from the U.S. and British governments.[23] They started mass production after the bombing of Pearl Harbor. By D-Day in 1944, enough penicillin had been produced to treat all the wounded in the Allied forces.

Purification and stabilisation

3D-model of benzylpenicillin

In Oxford, Ernst Boris Chain and Edward Abraham were studying the molecular structure of the antibiotic. Abraham was the first to propose the correct structure of penicillin.[24][25] Shortly after the team published its first results in 1940, Fleming telephoned Howard Florey, Chain's head of department, to say that he would be visiting within the next few days. When Chain heard that Fleming was coming, he remarked "Good God! I thought he was dead."[26]

Norman Heatley suggested transferring the active ingredient of penicillin back into water by changing its acidity. This produced enough of the drug to begin testing on animals. There were many more people involved in the Oxford team, and at one point the entire Dunn School was involved in its production. After the team had developed a method of purifying penicillin to an effective first stable form in 1940, several clinical trials ensued, and their amazing success inspired the team to develop methods for mass production and mass distribution in 1945.[27][28]

Fleming was modest about his part in the development of penicillin, describing his fame as the "Fleming Myth" and he praised Florey and Chain for transforming the laboratory curiosity into a practical drug. Fleming was the first to discover the properties of the active substance, giving him the privilege of naming it: penicillin. He also kept, grew, and distributed the original mould for twelve years, and continued until 1940 to try to get help from any chemist who had enough skill to make penicillin. But Sir Henry Harris said in 1998: "Without Fleming, no Chain; without Chain, no Florey; without Florey, no Heatley; without Heatley, no penicillin."[29] The discovery of penicillin and its subsequent development as a prescription drug mark the start of modern antibiotics.[30]


Modern antibiotics are tested using a method similar to Fleming's discovery.

The accidental discovery and isolation of penicillin by Fleming in September 1928 led to one of the first broadly effective antibiotic drug in medicine. Before that, several scientists had published or pointed out that mould or Penicillium sp. were able to inhibit bacterial growth, and even to cure bacterial infections in animals. Ernest Duchesne in 1897 in his thesis "Contribution to the study of vital competition in micro-organisms: antagonism between moulds and microbes",[31] or also Clodomiro Picado Twight whose work at the Institut Pasteur in 1923 on the inhibiting action of fungi of the Penicillin sp. genre in the growth of staphylococci drew little interest from the directors of the Institut at the time. Fleming was the first to push these studies further by isolating the penicillin, and by being motivated enough to promote his discovery at a larger scale.[32]

Fleming also discovered very early that bacteria developed antibiotic resistance whenever too little penicillin was used or when it was used for too short a period. Almroth Wright had predicted antibiotic resistance even before it was noticed during experiments. Fleming cautioned about the use of penicillin in his many speeches around the world. On 26 June 1945, he made the following cautionary statements: "the microbes are educated to resist penicillin and a host of penicillin-fast organisms is bred out ... In such cases the thoughtless person playing with penicillin is morally responsible for the death of the man who finally succumbs to infection with the penicillin-resistant organism. I hope this evil can be averted."[32] He cautioned not to use penicillin unless there was a properly diagnosed reason for it to be used, and that if it were used, never to use too little, or for too short a period, since these are the circumstances under which bacterial resistance to antibiotics develops.[33]


The popular story[34] of Winston Churchill's father paying for Fleming's education after Fleming's father saved young Winston from death is false. According to the biography, Penicillin Man: Alexander Fleming and the Antibiotic Revolution by Kevin Brown, Alexander Fleming, in a letter[35] to his friend and colleague Andre Gratia,[36] described this as "A wondrous fable." Nor did he save Winston Churchill himself during World War II. Churchill was saved by Lord Moran, using sulphonamides, since he had no experience with penicillin, when Churchill fell ill in Carthage in Tunisia in 1943. The Daily Telegraph and The Morning Post on 21 December 1943 wrote that he had been saved by penicillin. He was saved by the new sulphonamide drug Sulphapyridine, known at the time under the research code M&B 693, discovered and produced by May & Baker Ltd, Dagenham, Essex – a subsidiary of the French group Rhône-Poulenc. In a subsequent radio broadcast, Churchill referred to the new drug as "This admirable M&B".[37] It is highly probable that the correct information about the sulphonamide did not reach the newspapers because, since the original sulphonamide antibacterial, Prontosil, had been a discovery by the German laboratory Bayer, and as Britain was at war with Germany at the time, it was thought better to raise British morale by associating Churchill's cure with a British discovery, penicillin.

Awards and legacy

Display of Fleming's awards, including his Nobel Prize. Also shows a sample of penicillin and an example of an early apparatus for preparing it.
Fleming (centre) receiving the Nobel prize from King Gustaf V of Sweden (right) in 1945
Faroe Islands postage stamp commemorating Fleming
Barcelona to Sir Alexander Fleming (1956), by Catalan sculptor Josep Manuel Benedicto. Barcelona: jardins del Doctor Fleming.

Fleming's discovery of penicillin changed the world of modern medicine by introducing the age of useful antibiotics; penicillin has saved, and is still saving, millions of people around the world.[38]

The laboratory at St Mary's Hospital where Fleming discovered penicillin is home to the Fleming Museum, a popular London attraction. His alma mater, St Mary's Hospital Medical School, merged with Imperial College London in 1988. The Sir Alexander Fleming Building on the South Kensington campus was opened in 1998, where his son Robert and his great granddaughter Claire were presented to the Queen; it is now one of the main preclinical teaching sites of the Imperial College School of Medicine.

His other alma mater, the Royal Polytechnic Institution (now the University of Westminster) has named one of its student halls of residence Alexander Fleming House, which is near to Old Street.

Personal life

Grave of Alexander Fleming in the crypt of St Paul's Cathedral, London.

On 24 December 1915, Fleming married a trained nurse, Sarah Marion McElroy of Killala, County Mayo, Ireland. Their only child, Robert Fleming (1924–2015), became a general medical practitioner. After his first wife's death in 1949, Fleming married Dr. Amalia Koutsouri-Vourekas, a Greek colleague at St. Mary's, on 9 April 1953; she died in 1986.[48]

Fleming came from a Presbyterian background, while his first wife Sarah was a (lapsed) Roman Catholic. It is said that he was not particularly religious, and their son Robert was later received into the Anglican church, while still reportedly inheriting his two parents' fairly irreligious disposition.[49]

From 1921 until his death in 1955, Fleming owned a country home in Barton Mills, Suffolk.[50]


On 11 March 1955, Fleming died at his home in London of a heart attack. His ashes are buried in St Paul's Cathedral.[2]

See also


  1. 1.0 1.1 1.2 Colebrook, L. (1956). "Alexander Fleming 1881-1955". Biographical Memoirs of Fellows of the Royal Society. 2: 117–126. doi:10.1098/rsbm.1956.0008. JSTOR 769479.
  2. 2.0 2.1 "Sir Alexander Fleming – Biography". Nobel Foundation. Retrieved 25 October 2011.
  3. 3.0 3.1 3.2 "Alexander Fleming Biography". Les Prix Nobel. The Nobel Foundation. 1945. Retrieved 27 March 2011.
  4. Hugh, TB (2002). "Howard Florey, Alexander Fleming and the fairy tale of penicillin". The Medical Journal of Australia. 177 (1): 52–53, author 53 53. doi:10.5694/j.1326-5377.2002.tb04643.x. PMID 12436980.
  5. Cruickshank, Robert (1955). "Sir Alexander Fleming, F.R.S". Nature. 175 (4459): 663. Bibcode:1955Natur.175..663C. doi:10.1038/175663a0.
  6. McIntyre, N (2007). "Sir Alexander Fleming". Journal of Medical Biography. 15 (4): 234. doi:10.1258/j.jmb.2007.05-72. PMID 18615899.
  7. 7.0 7.1 7.2 7.3 Mazumdar, PM (1984). "Fleming as Bacteriologist: Alexander Fleming". Science. 225 (4667): 1140–1141. Bibcode:1984Sci...225.1140C. doi:10.1126/science.225.4667.1140. PMID 17782415.
  8. Brown, Kevin (2004). Penicillin man : Alexander Fleming and the antibiotic revolution. Stroud: Sutton. ISBN 978-0750931526. Retrieved 11 September 2015.
  9. 9.0 9.1 9.2 9.3 9.4 Kelly's Handbook to the Titled, Landed and Official Classes, 1955. Kelly's. p. 802.
  10. 10.0 10.1 Tan, SY; Tatsumura, Y (July 2015). "Alexander Fleming (1881–1955): Discoverer of penicillin". Singapore Medical Journal. 56 (7): 366–367. doi:10.11622/smedj.2015105. PMC 4520913. PMID 26243971.
  11. FLEMING, ALEXANDER (September 1917). "The Physiological and Antiseptic Action of Flavine (With Some Observations on the Testing of Antiseptics)". The Lancet. 190 (4905): 341–345. doi:10.1016/S0140-6736(01)52126-1.
  12. Fleming, A (1922). "On a remarkable bacteriolytic element found in tissues and secretions". Proceedings of the Royal Society B. 93 (653): 306–317. doi:10.1098/rspb.1922.0023.
  13. Haven, Kendall F. (1994). Marvels of Science : 50 Fascinating 5-Minute Reads. Littleton, Colo: Libraries Unlimited. p. 182. ISBN 1-56308-159-8.
  14. Bigger, Joseph W.; Boland, C. R.; O'meara, R. A. Q. (1927). "Variant colonies ofStaphylococcus aureus". The Journal of Pathology and Bacteriology (in English). 30 (2): 261–269. doi:10.1002/path.1700300204.
  15. Lalchhandama, Kholhring (2020). "Reappraising Fleming's snot and mould". Science Vision (in English). 20 (1): 29–42. doi:10.33493/scivis.20.01.03.
  16. Brown, K. (2004). Penicillin Man: Alexander Fleming and the Antibiotic Revolution. 320 pp. Sutton Publishing. ISBN 0-7509-3152-3.
  17. Hare, R. The Birth of Penicillin, Allen & Unwin, London, 1970
  18. Houbraken, Jos; Frisvad, Jens C.; Samson, Robert A. (2011). "Fleming's penicillin producing strain is not Penicillium chrysogenum but P. rubens". IMA Fungus (in English). 2 (1): 87–95. doi:10.5598/imafungus.2011.02.01.12. PMC 3317369. PMID 22679592.
  19. Hibbett, David S.; Taylor, John W. (2013). "Fungal systematics: is a new age of enlightenment at hand?". Nature Reviews Microbiology (in English). 11 (2): 129–133. doi:10.1038/nrmicro2963. PMID 23288349.
  20. Diggins, F. The true history of the discovery of penicillin by Alexander Fleming Biomedical Scientist, March 2003, Institute of Biomedical Sciences, London. (Originally published in the Imperial College School of Medicine Gazette)
  21. Fleming, A (1980). "On the antibacterial action of cultures of a penicillium, with special reference to their use in the isolation of B. influenzae. (Reprinted from the British Journal of Experimental Pathology 10:226–236, 1929)". Clin Infect Dis. 2 (1): 129–39. doi:10.1093/clinids/2.1.129. PMC 2041430. PMID 6994200.; Reprint of Fleming, A. (929). "On the Antibacterial Action of Cultures of a Penicillium, with Special Reference to their Use in the Isolation of B. influenzæ". Br J Exp Pathol. 10 (3): 226–236. PMC 2048009.
  22. Rossiter, Peter (10 September 2010). "Keith Bernard Rogers". BMJ. 331 (7516): 579. doi:10.1136/bmj.331.7516.579-c. PMC 1200632. Keith was probably the first patient to be treated clinically with the mould juice.
  23. Bickel, L. Florey: The Man Who Made Penicillin, Sun Books, Melbourne, 1972.
  24. in October 1943 Abraham proposed a molecular structure which included a cyclic formation containing three carbon atoms and one nitrogen atom, the β-lactam ring, not then known in natural products. This structure was not immediately published due to the restrictions of wartime secrecy, and was initially strongly disputed, by Sir Robert Robinson among others, but it was finally confirmed in 1945 by Dorothy Crowfoot Hodgkin using X-ray analysis." Oxford Dictionary of National Biography; "Abraham, Sir Edward Penley"
  25. Lowe, Gordon (13 May 1999). "Obituary: Sir Edward Abraham". The Independent. London.
  26. Yanes, Javier (6 August 2018). "Fleming and the Difficult Beginnings of Penicillin: Myth and Reality". OpenMind (in English). Retrieved 7 June 2020.
  27. Moberg, C. (1991). "Penicillin's forgotten man: Norman Heatley". Science (in English). 253 (5021): 734–735. doi:10.1126/science.1876832. PMID 1876832.
  28. "Norman Heatley". The Independent (in English). 23 January 2004. Retrieved 7 June 2020.
  29. Henry Harris, Howard Florey and the development of penicillin, a lecture given on 29 September 1998, at the Florey Centenary, 1898–1998, Sir William Dunn School of Pathology, Oxford University (sound recording) [1]
  30. Conly, J.M.; Johnston, B.L. (2005). "Where are all the new antibiotics? The new antibiotic paradox". Canadian Journal of Infectious Diseases and Medical Microbiology (in English). 16 (3): 159–160. doi:10.1155/2005/892058. PMC 2095020. PMID 18159536.
  31. Duchesne 1897, Antagonism between molds and bacteria. An English translation by Michael Witty. Fort Myers, 2013. ASIN B00E0KRZ0E and B00DZVXPIK.
  32. 32.0 32.1 Infection Control And Hospital Epidemiology. (April 2012). Policy Statement on Antimicrobial Stewardship by the Society for Healthcare Epidemiology of America (SHEA), the Infectious Diseases Society of America (IDSA), and the Pediatric Infectious Diseases Society (PIDS). Retrieved from
  33. Rosenblatt-Farrell, Noah (2009). "The Landscape of Antibiotic Resistance". Environmental Health Perspectives (in English). 117 (6): 244–150. doi:10.1289/ehp.117-a244. PMC 2702430. PMID 19590668.
  34. e.g., The Philadelphia Inquirer, 17 July 1945: Brown, Penicillin Man, note 43 to Chapter 2
  35. 14 November 1945; British Library Additional Manuscripts 56115: Brown, Penicillin Man, note 44 to Chapter 2
  36. see Wikipedia Discovery of penicillin article entry for 1920
  37. A History of May & Baker 1834–1984, Alden Press 1984.
  38. Roberts, Michael; Ingram, Neil (2001). Biology (2, illustrated ed.). Nelson Thornes. p. 105. ISBN 0-7487-6238-8. Retrieved 4 March 2012. Penicillin is just one of a very large number of drugs which today are used by doctors to treat people with diseases.
  39. "100,000 visitors in 6 days". National Museums Scotland. 3 August 2011. Archived from the original on 23 February 2012. Retrieved 4 March 2012.
  40. "No. 36544". The London Gazette (Supplement). 2 June 1944. p. 2566.
  41. "People of the century". P. 78. CBS News. Simon & Schuster, 1999
  42. "Alexander Fleming – Time 100 People of the Century". Time. 29 March 1999.
  43. "Discovery and Development of Penicillin". International Historic Chemical Landmarks. American Chemical Society. Retrieved 21 August 2018.
  44. "BBC – Great Britons – Top 100". Internet Archive. Archived from the original on 4 December 2002. Retrieved 19 July 2017.
  45. 45.0 45.1 Edward Lewine (2007). "Death and the Sun: A Matador's Season in the Heart of Spain". p. 123. Houghton Mifflin Harcourt, 2007
  46. "Banknote designs mark Homecoming". BBC News. 14 January 2008. Archived from the original on 25 January 2009. Retrieved 20 January 2009.
  47. "Robert Burns voted Greatest Scot". STV Group. 30 November 2009. Archived from the original on 6 November 2018. Retrieved 7 February 2016.
  48. Biographical Index of Former Fellows of the Royal Society of Edinburgh 1783–2002 (PDF). The Royal Society of Edinburgh. July 2006. ISBN 0-902-198-84-X.
  49. Penicillin Man: Alexander Fleming and the Antibiotic Revolution. The History Press. September 2005. ISBN 0750931531.
  50. local history. Retrieved 17 October 2016.

Further reading

  • The Life Of Sir Alexander Fleming, Jonathan Cape, 1959. Maurois, André.
  • Nobel Lectures, the Physiology or Medicine 1942–1962, Elsevier Publishing Company, Amsterdam, 1964
  • An Outline History of Medicine. London: Butterworths, 1985. Rhodes, Philip.
  • The Cambridge Illustrated History of Medicine. Cambridge, England: Cambridge University Press, 1996. Porter, Roy, ed.
  • Penicillin Man: Alexander Fleming and the Antibiotic Revolution, Stroud, Sutton, 2004. Brown, Kevin.
  • Alexander Fleming: The Man and the Myth, Oxford University Press, Oxford, 1984. Macfarlane, Gwyn
  • Fleming, Discoverer of Penicillin, Ludovici, Laurence J., 1952
  • The Penicillin Man: the Story of Sir Alexander Fleming, Lutterworth Press, 1957, Rowland, John.

External links

Media related to Lua error in Module:Commons_link at line 64: attempt to index field 'wikibase' (a nil value). at Wikimedia Commons

Academic offices
Preceded by
Rector of the University of Edinburgh
Succeeded by

Template:Nobel Prize in Physiology or Medicine Laureates 1926-1950 Template:1945 Nobel Prize winners

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