1842 in science

• October 5 – Josef Groll brews the first pilsner light lager beer in the city of Pilsen, Bohemia (modern-day Czech Republic).

• Nathaniel Bagshaw Ward publishes On the Growth of Plants in Closely Glazed Cases in London, promoting his concept of the Wardian case.{{cite journal|first=David|last=Hershey|title=Doctor Ward's Accidental Terrarium|journal=The American Biology Teacher|volume=58|issue=5|pages=276–281|year=1996|doi=10.2307/4450151|jstor=4450151}}

• Antarctic explorer James Clark Ross charts the eastern side of James Ross Island and on January 23 reaches a Farthest South of 78°09'30"S.{{cite book|last=Coleman|first=E. C.|title=The Royal Navy in Polar Exploration, from Frobisher to Ross|publisher=Tempus Publishing|location=Stroud|year=2006|isbn=978-0-7524-3660-9|page=335}}

• January – American medical student William E. Clarke of Berkshire Medical College becomes the first person to administer an inhaled anesthetic to facilitate a surgical procedure. After Clarke uses a towel and ether to anesthetize a patient identifed as "Miss Hobbie", Dr. Elijah Pope carries out a dental extraction.{{cite book|title=Artificial anaesthesia and anaesthetics|chapter=History of anaesthesia|page=6|author=Lyman, H. M.|year=1881|publisher=William Wood and Company|location=New York|chapter-url=https://books.google.com/books?id=xNEIAQAAIAAJ&q=Artificial%20anaesthesia%20and%20anaesthetics&pg=PA68|accessdate=2010-09-13}}
• March 30 – American physician and pharmacist Crawford Long administers an inhaled anesthetic (diethyl ether) to facilitate a surgical procedure (removal of a neck tumor).{{cite journal|last=Long|first=C. W.|title=An account of the first use of Sulphuric Ether by Inhalation as an Anæsthetic in Surgical Operations|journal=Southern Medical and Surgical Journal|volume=5|pages=705–13|year=1849|url=http://journals.lww.com/surveyanesthesiology/Citation/1991/12000/An_Account_of_the_First_Use_of_Sulphuric_Ether_by.49.aspx|accessdate=2012-06-12}}{{cite magazine|url=https://www.wired.com/science/discoveries/news/2007/03/dayintech_0330|title=March 30, 1842: It's Lights Out, Thanks to Ether|magazine=Wired|last=Long|first=Tony|date=2007-03-30|accessdate=2007-12-29}}
• English surgeon William Bowman publishes On the Structure and Use of the Malpighian Bodies of the Kidney,Presented to the Royal Society of London. identifying Bowman's capsule, a key component of the nephron.
• Edwin Chadwick's critical Report on an inquiry into the Sanitary Condition of the Labouring Population of Great Britain is published by the Poor Law Commission.{{cite web|url=http://www.icons.org.uk/theicons/icons-timeline/1840-1860 |title=Icons, a portrait of England 1840–1860 |accessdate=2007-09-13 |archiveurl=https://web.archive.org/web/20070817165102/http://www.icons.org.uk/theicons/icons-timeline/1840-1860 |archivedate=2007-08-17 |url-status=dead }}

• British palaeontologist Richard Owen coins the name Dinosauria, hence the Anglicized dinosaur.Owen, R. (1842). "Report on British Fossil Reptiles." Part II. Report of the British Association for the Advancement of Science, Plymouth, England.

• Christian Doppler proposes the Doppler effect."Über das farbige Licht der Doppelsterne und einiger anderer Gestirne des Himmels – Versuch einer das Bradley'sche Theorem als integrirenden Theil in sich schliessenden allgemeineren Theorie" ("On the coloured light of the binary refracted stars and other celestial bodies – Attempt of a more general theory including Bradley's theorem as an integral part"). Abhandlungen der kaiserlichen bõhm. Gesellschaft der Wissenschaften zu Prag (Prague) V Folge 2. 25 May 1842.
• Julius Robert von Mayer proposes that work and heat are equivalent.{{cite journal|last=von Mayer|first=J. R.|year=1842|title=Bemerkungen über die Kräfte der unbelebten Nature ("Remarks on the forces of inorganic nature")|journal=Annalen der Chemie und Pharmacie|volume=43|issue=2|pages=233–40|doi=10.1002/jlac.18420420212|hdl=2027/umn.319510020751527|hdl-access=free}} This is independently discovered in 1843 by James Prescott Joule, who names it "mechanical equivalent of heat".

• January 8 – Delft University of Technology established by William II of the Netherlands as a 'Royal Academy for the education of civilian engineers'.{{cite web|url=http://www.tudelft.nl/live/pagina.jsp?id=300c4edd-74f6-4f4d-a5cd-42a70682cb98&lang=en |title=History of the university |publisher=TU Delft |accessdate=2012-07-10 |url-status=dead |archiveurl=https://web.archive.org/web/20080228094426/http://www.tudelft.nl/live/pagina.jsp?id=300c4edd-74f6-4f4d-a5cd-42a70682cb98&lang=en |archivedate=2008-02-28 }}
• February 21 – John Greenough is granted the first U.S. patent for the sewing machine.{{cite web|url=http://www.vdta.com/hof-list.html|title=Vacuum & Sewing Hall of Fame|accessdate=2007-12-29|archiveurl=https://web.archive.org/web/20071212185533/http://www.vdta.com/hof-list.html|archivedate=12 December 2007|url-status=live}} See section: "Contributors to the invention of the sewing machine".
• June – James Nasmyth patents his design of steam hammer in England and introduces an improved planing machine.{{cite book|last=Smiles|first=Samuel|authorlink=Samuel Smiles|title=James Nasmyth Engineer: an Autobiography|publisher=John Murray|year=1912|url=https://archive.org/details/jamesnasmythengi00nasmiala|accessdate=2009-11-14}}
• John Herschel discovers the cyanotype (blueprint) photographic process in England.{{Cite web|title=The Cyanotype|last=Rosenthal|first=Richard T.|work=Vernacular Photography|year=2000|access-date=2021-11-23|url=http://vernacularphotography.com/vpm/v1n1/the_cyanotype.htm|archive-url=https://web.archive.org/web/20130330080304/http://vernacularphotography.com/vpm/v1n1/the_cyanotype.htm|archive-date=2013-03-30|url-status=dead}}

• September 14–17 – English naturalist Charles Darwin and his family settle at Down House in Kent.

• Copley Medal: James MacCullagh{{cite web |title=Copley Medal {{!}} British scientific award |url=https://www.britannica.com/science/Copley-Medal |website=Encyclopedia Britannica |accessdate=22 July 2020 |language=en}}
• Wollaston Medal: Leopold von Buch

• February 2 – Julian Sochocki (died 1927), Polish mathematician.
• February 10 – Agnes Mary Clerke (died 1907) Irish astronomer and author.{{cite book|first1=Catharine M C|last1=Haines|first2=Helen M|last2=Stevens|title=International Women in Science: A Biographical Dictionary to 1950|location=Santa Barbara|publisher=ABC-CLIO|year=2001|page=66|isbn=978-1-57607-090-1}}
• February 22 – Camille Flammarion (died 1925), French astronomer.
• March 17 – Rosina Heikel (died 1929), Finnish physician.{{cite book|first=Arvid|last=Bernce|title=Efter 1809 en Krönika i ord och bild om Finlandssvenskarna|location=Helsingfors|publisher=Bernces förlag|year=1981|page=2003|isbn=978-9-15000-408-3|lang=SV}}
• March 23 – Susan Jane Cunningham (died 1921), American mathematician.
• April 4 – Édouard Lucas (died 1891, French mathematician.
• May 7 – Isala Van Diest (died 1916), Belgian physician.
• May 8 – Emil Christian Hansen (died 1909), Danish fermentation physiologist.
• June 11 – Carl von Linde (died 1934), German refrigeration engineer.
• August 23 – Osborne Reynolds (died 1912), Irish-born physicist.
• September 9 – Elliott Coues (died 1899), American ornithologist.
• September 20
• James Dewar (died 1923), Scottish-born chemist.
• Charles Lapworth (died 1920), English geologist.
• October 17 – Gustaf Retzius (died 1919), Swedish anatomist.
• October 24 (O.S. October 12) – Nikolai Menshutkin (died 1907), Russian chemist.
• November 12 – John William Strutt, 3rd Baron Rayleigh (died 1919), English Nobel Prize-winning physicist.
• December 3 – Ellen Swallow Richards (d. 1911), American chemist.
• December 17 – Sophus Lie (died 1899), Norwegian mathematician.

• February 15 – Archibald Menzies (born 1754), Scottish-born botanist.
• April 28 – Charles Bell (born 1774), Scottish-born anatomist.
• May 8 – Jules Dumont d'Urville (born 1790), French explorer.
• June 9 - Maria Dalle Donne (born 1778), Bolognese physician
• June 30 – Thomas Coke, Earl of Leicester (born 1754), English agriculturalist and geneticist.
• July 19 – Pierre Joseph Pelletier (born 1788), French chemist.
• July 25 – Dominique Jean Larrey (born 1766), French military surgeon, pioneer of battlefield medicine.

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Category:19th century in science

Category:1840s in science