1826 in science
- Mary Somerville presents a paper on "The Magnetic Properties of the Violet Rays of the Solar Spectrum" to the Royal Society in London.
- Antoine Jerome Balard isolates bromine.
- Pierre Jean Robiquet isolates the dye alizarin.
- Michael Faraday determines the chemical formula of naphthalene.
- May 22 – HMS Beagle departs on her first voyage from Plymouth for a hydrographic survey of the Patagonia and Tierra del Fuego regions of South America.
- Hyacinthe de Bougainville completes a three-year global circumnavigation.
- Journal für die reine und angewandte Mathematik is founded by August Leopold Crelle in Berlin.
- February – Nikolai Lobachevsky first presents his system of non-Euclidean hyperbolic geometry.
Physiology and medicine
- Johannes Peter Müller publishes his first important works, Zur vergleichenden Physiologie des Gesichtsinns ("On the comparative physiology of sight", Leipzig) and Über die phantastischen Gesichtserscheinungen ("On visual hallucination", Coblenz), making a first statement of the law of specific nerve energies.
- January 30 – The Menai Suspension Bridge, built by engineer Thomas Telford, is opened between the island of Anglesey and the mainland of Wales.
- April 1 – American inventor Samuel Morey patents a compressionless internal combustion engine in the United States.
- June – Nicéphore Niépce produces the first photograph, View from the Window at Le Gras.
- Benoit Fourneyron develops an efficient outward-flow water turbine.
- Karl Ernst von Baer discovers the mammalian ovum.
- The Austrian zoologist Johann Nepomuk Meyer first described the Asiatic lion under the name Felis leo persicus.
- The Zoological Society of London is founded by Sir Thomas Stamford Raffles.
- January 15 – Marie Pasteur (died 1910), French chemist.
- May 26 – Richard Carrington (died 1875), English astronomer.
- June 26 – Morgan Crofton (died 1915), Irish mathematician.
- July 7 – John Fowler (died 1864), English agricultural engineer.
- July 13 – Stanislao Cannizzaro (died 1910), Italian chemist.
- September 17 – Bernhard Riemann (died 1866), German mathematician.
- October 8 – Emily Blackwell (died 1910), American physician.
- January 3 – Marie Le Masson Le Golft (born 1750), French naturalist.
- January 6 – John Farey (born 1766), English geologist.
- June 7 – Joseph von Fraunhofer (born 1787), German physicist.
- July 4 – Thomas Jefferson (born 1743), Founding Father and 3rd President of the United States and inventor.
- July 22 – Giuseppe Piazzi (born 1746), Italian astronomer.
- October 25 – Philippe Pinel (born 1745), French psychiatrist.
- November 23 – Johann Elert Bode (born 1747), German astronomer.
- Robiquet, Pierre-Jean; Colin, Jean-Jacques (1826). "Sur un nouveau principe immédiat des vègétaux (l’alizarin) obtenu de la garance" [On a new substance from plants (alizarin) obtained from madder]. Journal de pharmacie et des sciences accessoires 2nd series, 12:407–412; Colin, Jean-Jacques; Robiquet, Pierre-Jean (1827). "Nouvelles recherches sur la matierè colorante de la garance" [New research into the coloring material of madder]. Annales de chimie et de physique 2nd series, 34:225–253.
- Rolt, L. T. C. (1958). Thomas Telford. London: Longmans, Green.
- X4,378 Gas Or Vapor Engine
- Hardenberg, Horst O. (1992). Samuel Morey and his atmospheric engine. SP-922. Warrendale, Pa.: Society of Automotive Engineers. ISBN 1-56091-240-5.
- Maurer, Leon. "The Unsolved Mystery of Samuel Morey". Archived from the original on 2013-11-03. Retrieved 2013-11-01.
- "The First Photograph". Harry Ransom Center, University of Texas at Austin. Retrieved 2013-11-01.
- Reported as "Ovi Mammalium et Hominis genesi" to the Imperial Academy of Sciences in Saint Petersburg in 1827 (published at Leipzig).
- Petrunkevitch, Alexander (1920). "Russia's Contribution to Science". Transactions of the Connecticut Academy of Arts and Sciences. 23: 236.
- "Биография Бэр Карл Максимович". AllPersona.Ru. Archived from the original on 2008-03-19. Retrieved 2011-05-18.
- Meyer, J. N. (1826). Dissertatio inauguralis anatomico-medica de genere felium. Doctoral thesis, University of Vienna.