William Prout

William Prout FRS (/praʊt/; 15 January 1785 – 9 April 1850) was an English chemist, physician, and natural theologian. He is remembered today mainly for what is called Prout's hypothesis.

William Prout
Prout William painting
Portrait of William Prout
by Henry Wyndham Phillips[1]
Born15 January 1785
Died9 April 1850 (aged 65)
London, England[2]
Alma materEdinburgh University (M.D.) (1811)[2]
Known forProut's hypothesis
AwardsCopley Medal (1827)
Scientific career


Prout was born in Horton, Gloucestershire in 1785 and educated at 17 years of age by a clergyman, followed by the Redland Academy at Bristol and Edinburgh University, where he graduated in 1811 with an MD.[3] His professional life was spent as a practising physician in London, but he also occupied himself with chemical research. He was an active worker in biological chemistry and carried out many analyses of the secretions of living organisms, which he believed were produced by the breakdown of bodily tissues. In 1823, he discovered that stomach juices contain hydrochloric acid, which can be separated from gastric juice by distillation. In 1827, he proposed the classification of substances in food into sugars and starches, oily bodies, and albumen, which would later become known as carbohydrates, fats, and proteins.[4]

Prout William calculi
Different species of urinary calculi noted by William Prout[5]

Prout is better remembered, however, for his researches into physical chemistry. In 1815, based on the tables of atomic weights available at the time, he anonymously hypothesized that the atomic weight of every element is an integer multiple of that of hydrogen, suggesting that the hydrogen atom is the only truly fundamental particle (which he called protyle[6]), and that the atoms of the other elements are made of groupings of various numbers of hydrogen atoms. While Prout's hypothesis was not borne out by later more-accurate measurements of atomic weights, it was a sufficiently fundamental insight into the structure of the atom that in 1920, Ernest Rutherford chose the name of the newly discovered proton to, among other reasons, give credit to Prout.

Prout contributed to the improvement of the barometer, and the Royal Society of London adopted his design as a national standard.

He was elected a Fellow of the Royal Society in 1819.[7] He delivered the Goulstonian Lecture to the Royal College of Physicians in 1831 on the application of chemistry to medicine.[3]

Prout wrote the eighth Bridgewater Treatise, Chemistry, Meteorology, and the Function of Digestion, considered with reference to Natural Theology. It was in this work that he coined the term "convection" to describe a type of energy transfer.[8][9]

In 1814, Prout married Agnes Adam, daughter of Alexander Adam, of Edinburgh, Scotland, and together they had six children.[10] Prout died in London in 1850 and was buried in Kensal Green Cemetery.

The "Prout" is a unit of nuclear binding energy, and is 1/12 the binding energy of the deuteron, or 185.5 keV. It is named after William Prout. "Proutons" was an early candidate for the name of what are now called protons.

Honours and awards


See also


  1. ^ Rosenfeld, Louis (2003). "William Prout: Early 19th Century Physician-Chemist". Clinical Chemistry. 49 (4): 699–705. doi:10.1373/49.4.699. PMID 12651838.
  2. ^ a b britannica.com
  3. ^ a b "William Prout – Philosopher-Physician". BMJ. 2 (4421): 437. 1945. doi:10.1136/bmj.2.4421.437-a. PMC 2059932.
  4. ^ Price, Catherine (2018). "Probing the Mysteries of Human Digestion". Distillations. 4 (2): 27–35. Retrieved 30 October 2018.
  5. ^ Prout, William (1825). An Inquiry into the Nature and Treatment of Diabetes, Calculus, and Other Affections of the Urinary Organs (2 ed.). London: Baldwin, Craddock, and Joy.
  6. ^ Lederman, Leon (1993). The God Particle.
  7. ^ "Lists of Royal Society Fellows 1660–2007". London: The Royal Society. Archived from the original on 24 March 2010. Retrieved 14 July 2010.
  8. ^ Burr, A. C. (1934). "Notes on the History of the Experimental Determination of the Thermal Conductivity of Gases". Isis. 21: 169–186. doi:10.1086/346837.
  9. ^ Brock, W. H. (1970). "William Prout and Barometry". Notes and Records of the Royal Society of London. 24 (2): 281–294. doi:10.1098/rsnr.1970.0020.
  10. ^ Brock, W. H. (1963). "Prout's Chemical Bridgewater Treatise". Journal of Chemical Education. 40 (12): 652–655. doi:10.1021/ed040p652.


Further reading

1785 in science

The year 1785 in science and technology involved some significant events.

1815 in science

The year 1815 in science and technology involved some significant events, listed below.

1827 in science

The year 1827 in science and technology involved some significant events, listed below.

1850 in science

The year 1850 in science and technology involved some significant events, listed below.

1850 in the United Kingdom

Events from the year 1850 in the United Kingdom.


Gastroenterology is the branch of medicine focused on the digestive system and its disorders.

Diseases affecting the gastrointestinal tract, which include the organs from mouth into anus, along the alimentary canal, are the focus of this speciality. Physicians practicing in this field are called gastroenterologists. They have usually completed about eight years of pre-medical and medical education, a year-long internship (if this is not a part of the residency), three years of an internal medicine residency, and two to three years in the gastroenterology fellowship. Gastroenterologists perform a number of diagnostic and therapeutic procedures including colonoscopy, endoscopy, endoscopic retrograde cholangiancreatography (ERCP), endoscopic ultrasound and liver biopsy. Some gastroenterology trainees will complete a "fourth-year" (although this is often their seventh year of graduate medical education) in transplant hepatology, advanced endoscopy, inflammatory bowel disease, motility or other topics.

Hepatology, or hepatobiliary medicine, encompasses the study of the liver, pancreas, and biliary tree, while proctology encompasses the fields of anus and rectum diseases. They are traditionally considered sub-specialties of gastroenterology.

George Prout (footballer)

George William Prout (3 November 1902 – 1960) was an English professional footballer who played as a goalkeeper.

Henry Wyndham Phillips

Henry Wyndham Phillips (1820 – 8 December 1868) was a British artist and portrait painter. Although he produced and exhibited a small number of paintings of scriptural subjects early on in his career, he spent most of his life working as a portrait artist. He was born in London, the younger son of the portraitist Thomas Phillips, from whom he received most of his art tuition. When his father died in 1845, he bequeathed Henry all of his painting materials and the use of his painting rooms at 8, George Street, Hanover Square in central London, where Henry is believed to have lived for the rest of his life.He was a very popular and sought-after portrait artist. His commissions included the portraits of actor Charles Kean (as Louis XI) for the Garrick Club, Dr William Prout for the Royal College of Physicians, and Robert Stephenson for the Institution of Civil Engineers. Some of his works, including his portrait of the famous archaeologist, Austen Layard, were popular engravings. His works were exhibited at the Royal Academy and the British Institute from 1838 until his death in 1868.Phillips was a close friend of George Frederic Watts, with whom he was a founding member of London's Cosmopolitan Club (est. 1852), where he was also honorary secretary. He served as secretary of the Artists' General Benevolent Institution for thirteen years. He was also a captain in the Artists Rifles Volunteer Force, which he established in 1860 at his art studio along with fellow founding commander Frederic Leighton.He married the poet Susan K. Phillips (née Holdsworth) in 1856. He died suddenly on 8 December 1868, in Sydenham, Kent, and was buried at West Norwood Cemetery.

History of the periodic table

The periodic table is an arrangement of the chemical elements, which are organized on the basis of their atomic numbers, electron configurations and recurring chemical properties. Elements are presented in order of increasing atomic number. The standard form of the table consists of a grid with rows called periods and columns called groups.

The history of the periodic table reflects over two centuries of growth in the understanding of chemical properties, with major contributions made by Antoine-Laurent de Lavoisier, Johann Wolfgang Döbereiner, John Newlands, Julius Lothar Meyer, Dmitri Mendeleev, and Glenn T. Seaborg.

Homogentisic acid

Homogentisic acid (2,5-dihydroxyphenylacetic acid) is a phenolic acid usually found in Arbutus unedo (strawberry-tree) honey. It is also present in the bacterial plant pathogen Xanthomonas campestris pv. phaseoli as well as in the yeast Yarrowia lipolytica where it is associated with the production of brown pigments. It is oxidatively dimerised to form hipposudoric acid, one of the main constituents of the 'blood sweat' of hippopotamuses.

It is less commonly known as melanic acid, the name chosen by William Prout.

List of Fellows of the Royal Society elected in 1819

Fellows of the Royal Society elected in 1819.

Natural theology

Natural theology, once also termed physico-theology, is a type of theology that provides arguments for the existence of God based on reason and ordinary experience of nature.

This distinguishes it from revealed theology, which is based on scripture and/or religious experiences, and from transcendental theology, which is based on a priori reasoning. It is thus a type of philosophy, with the aim of explaining the nature of the gods, or of one supreme God. For monotheistic religions, this principally involves arguments about the attributes or non-attributes of God, and especially the existence of God, using arguments that do not involve recourse to supernatural revelation.

Marcus Terentius Varro (116–27 BC) established a distinction between political theology (the social functions of religion), natural theology and mythical theology. His terminology became part of the Stoic tradition and then Christianity through Augustine of Hippo and Thomas Aquinas.


Prout may refer to:

People with the surname Prout:

Christopher Prout, Baron Kingsland (1942–2009), British politician

Ebenezer Prout (1835–1909), English composer, music theorist, writer and teacher

Elizabeth Prout (1820–1864), Catholic nun and Servant of God

Francis Sylvester Mahony (1804–1866), Irish humorist known as Father Prout

Frank Prout (1921–2011), British canoer

Gavin Prout (born 1978), Canadian lacrosse player

George Prout (1878 – c. 1980), Canadian politician

John Skinner Prout (1805–1876), artist, nephew of Samuel Prout

John T. Prout (1880–1969), Irish American soldier

Kirsten Prout (born 1990), Canadian actress

Louis Beethoven Prout (1864–1943), English entomologist and musicologist, son of Ebenezer Prout

Richard Prout (born 1967), British entrepreneur, founder of Intracus Ltd

Roland Prout (1920–1997), British canoer

Samuel Prout (1783–1852), British watercolourist

Victor Albert Prout (1835–1877), British portrait painter and professional photographer

Victor William Prout (1862–1950), son of Victor Albert Prout

William Prout (1785–1850), English chemist and physicist

William C. Prout (1886–1927), American athleteOther:

Progressive Utilization Theory

Prout College

Prout (unit), unit of nuclear binding energy

Prout School, a high school in Rhode Island, United States

Prout's hypothesis

Prouts Neck, Maine

Reliques of Father Prout

Prout's hypothesis

Prout's hypothesis was an early 19th-century attempt to explain the existence of the various chemical elements through a hypothesis regarding the internal structure of the atom. In 1815 and 1816, the English chemist William Prout published two papers in which he observed that the atomic weights that had been measured for the elements known at that time appeared to be whole multiples of the atomic weight of hydrogen. He then hypothesized that the hydrogen atom was the only truly fundamental object, which he called protyle, and that the atoms of other elements were actually groupings of various numbers of hydrogen atoms.Prout's hypothesis was an influence on Ernest Rutherford when he succeeded in "knocking" hydrogen nuclei out of nitrogen atoms with alpha particles in 1917, and thus concluded that perhaps the nuclei of all elements were made of such particles (the hydrogen nucleus), which in 1920 he suggested be named protons, from the suffix "-on" for particles, added to the stem of Prout's word "protyle".The discrepancy between Prout's hypothesis and the known variation of some atomic weights to values far from integral multiples of hydrogen, was explained between 1913 and 1932 by the discovery of isotopes and the neutron. According to the whole number rule of Francis Aston, Prout's hypothesis is correct for atomic masses of individual isotopes, with an error of at most 1%.

Timeline of particle physics

The timeline of particle physics lists the sequence of particle physics theories and discoveries in chronological order. The most modern developments follow the scientific development of the discipline of particle physics.

Whole number rule

The whole number rule states that the masses of the isotopes are whole number multiples of the mass of the hydrogen atom. The rule is a modified version of Prout's hypothesis proposed in 1815, to the effect that atomic weights are multiples of the weight of the hydrogen atom. It is also known as the Aston whole number rule after Francis W. Aston who was awarded the Nobel Prize in Chemistry in 1922 "for his discovery, by means of his mass spectrograph, of isotopes, in a large number of non-radioactive elements, and for his enunciation of the whole-number rule."

William C. Prout

William Christopher Prout (December 24, 1886 – August 4, 1927) was an American athlete. He competed at the 1908 Summer Olympics in London. He was also the tenth state deputy of the Massachusetts Knights of Columbus from 1921 to 1924.

William Hodson Brock

William Hodson Brock (born 1936) is a British chemist and science historian.

Brock was born in Brighton. He studied chemistry at University College London and the history and philosophy of science at the University of Leicester to become a lecturer on the subject. His earned a Ph.D. for his biography of the chemist William Prout which was expanded into the book, From Protyle to Proton: William Prout and the Nature of Matter, 1785–1985 (1985). Brock remained at Leicester until he retired in 1998 as Emeritus Professor of History of Science.Brock has written biographies of famous chemists such as Justus von Liebig, August Wilhelm von Hofmann and William Crookes.

Copley Medallists (1801–1850)

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