Editing 1845 in science

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{{Science year nav|1845}}

The year '''1845 in [[science]]''' and [[technology]] involved some significant events, listed below.

==Astronomy==
* April – [[William Parsons, 3rd Earl of Rosse|Lord Rosse]] discovers that the nebula [[Whirlpool Galaxy|M51]] has a spiral structure.
* September–October – [[Cornish people|Cornish]] mathematician [[John Couch Adams]] communicates to [[James Challis]] and [[George Biddell Airy]] his calculations demonstrating that a body ([[Neptune]]) is perturbing the orbit of [[Uranus]].<ref>{{cite journal|first1=William|last1=Sheehan|first2=Nicholas|last2=Kollerstrom|first3=Craig B.|last3=Waff|url=http://www.sciam.com/article.cfm?articleID=000CA850-8EA4-119B-8EA483414B7FFE9F|title=The Case of the Pilfered Planet - Did the British steal Neptune?|journal=[[Scientific American]]|date=2004-11-22|volume=291|issue=6|pages=92–99|doi=10.1038/scientificamerican1204-92|pmid=15597985|url-access=subscription}}</ref>
* November 10 – [[Urbain Le Verrier]] presents to the ''[[Académie des sciences]]'' in Paris a memoir showing that existing theories fail to account for the motion of Uranus.<ref>{{Cite EB1911|wstitle=Adams, John Couch}}</ref>
* Construction begins in [[Ireland]] of the "[[Leviathan of Parsonstown]]", a [[telescope]] built by Lord Rosse.

==Biology==
* August–September – Previously unknown [[Potato blight]] strikes the [[potato]] crop in Ireland: start of the [[Great Famine (Ireland)|Great Famine]].<ref>{{cite web|url=http://www.bbc.co.uk/northernireland/ashorthistory/archive/intro181.shtml|title=BBC Short History of Ireland}}</ref><ref>{{cite book|last=Palmer|first=Alan|last2=Palmer |first2=Veronica|year=1992|title=The Chronology of British History|publisher=Century Ltd|location=London|pages=267–268|isbn=0-7126-5616-2}}</ref>

==Chemistry==
* March 17 – [[Stephen Perry (inventor)|Stephen Perry]] patents the [[rubber band]] in [[England]].<ref>{{cite book|title=Penguin Pocket On This Day|publisher=Penguin Reference Library|isbn=0-14-102715-0|year=2006}}</ref>
* [[Edmond Frémy]] discovers the [[oxidizing agent]] [[Frémy's salt]].

==Exploration==
* August – [[John Franklin]]'s [[Franklin's lost expedition|expedition]] with [[HMS Erebus (1826)|HMS ''Erebus'']] and [[HMS Terror (1813)|HMS ''Terror'']] to find the [[Northwest Passage]] is last seen entering [[Baffin Bay]] prior to its mysterious disappearance.<ref>{{cite book|title=The Hutchinson Factfinder|publisher=Helicon|year=1999|isbn=1-85986-000-1|page=549}}</ref>

==Medicine==
* December 27 – [[Anesthesia]] is used in [[childbirth]] for the first time, by Dr [[Crawford Long]] in [[Jefferson, Georgia]].

==Physics==
* September 13 – [[Michael Faraday]] discovers that an intense [[magnetic field]] can rotate the plane of polarized light, the [[Faraday effect]].
* [[C. H. D. Buys Ballot]] confirms the [[Doppler effect]] for [[sound wave]]s.<ref>{{cite journal|last=Buys Ballot|first=C. H. D.|title=Akustische Versuche auf der Niederländischen Eisenbahn, nebst gelegentlichen Bemerkungen zur Theorie des Hrn. Prof. Doppler|language=German|journal=Annalen der Physik und Chemie|year=1845|volume=142|issue=11|pages=321–351|doi=10.1002/andp.18451421102|bibcode=1845AnP...142..321B|url=https://zenodo.org/record/1423606}}</ref>
* [[Kirchhoff's circuit laws]] are first described by German physicist [[Gustav Kirchhoff]].

==Technology==
* July 26–August 10 – [[Isambard Kingdom Brunel]]’s iron [[steamship]] ''[[SS Great Britain|Great Britain]]'' makes the [[Transatlantic Crossing]] from [[Liverpool]] to [[New York City|New York]], the first [[Propeller|screw propelled]] vessel to make the passage.<ref>{{cite book|last=Fox|first=Stephen|year=2003|title=Transatlantic: Samuel Cunard, Isambard Brunel, and the Great Atlantic Steamships|publisher=HarperCollins|isbn=978-0-06-019595-3|url-access=registration|url=https://archive.org/details/transatlanticsam00foxs}}</ref><ref>{{cite web|title=''Great Britain'' |url=http://www.theshipslist.com/pictures/Greatbritain.htm |work=The Ships List |accessdate=2010-10-01 |url-status=dead |archiveurl=https://web.archive.org/web/20100528131641/http://www.theshipslist.com/pictures/Greatbritain.htm |archivedate=2010-05-28 }}</ref>
* The [[saxhorn]] family of valved [[brass instrument]]s is [[patent]]ed by [[Adolphe Sax]] in France.

==Publications==
* January 14 – [[Deutsche Physikalische Gesellschaft|Physikalische Gesellschaft zu Berlin]] established and begins publishing ''[[Fortschritte der Physik]]'' and ''[[Verhandlungen]]''.
* August 28 – The journal ''[[Scientific American]]'' begins publication.
* [[Alexander von Humboldt]]'s ''Kosmos: Entwurf einer physischen Weltbeschreibung'' begins publication.

==Awards==
* [[Copley Medal]]: [[Theodor Schwann]]<ref>{{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}}</ref>
* [[Wollaston Medal]] for Geology: [[John Phillips (geologist)|John Phillips]]

==Births==
*February 17 (Old Style March 1) – [[Fyodor Pirotsky]] (died [[1898 in science|1898]]), Ukrainian-born Russian military and electrical engineer and inventor.
* March 3 – [[Georg Cantor]] (died [[1918 in science|1918]]), Russian-born German [[mathematician]].
* March 27 – [[Wilhelm Röntgen]] (died [[1923 in science|1923]]), German [[physicist]], discoverer of [[X-rays]], [[Nobel laureate]].
* April 21 – [[William Healey Dall]] (died [[1927 in science|1927]]), American [[malacologist]] and explorer.
* May 4 – [[William Kingdon Clifford]] (died [[1879 in science|1879]]), English [[geometer]].
* May 16 – [[Élie Metchnikoff]] (died [[1916 in science|1916]]), Russian-born [[microbiologist]], Nobel laureate.
* June 16 – [[Heinrich Dressel]] (died [[1920 in science|1920]]), German [[archaeologist]].
* July 4 – [[Thomas John Barnardo|Thomas Barnardo]] (died [[1905 in science|1905]]), Irish-born [[physician]] and [[philanthropist]].
* September 11 – [[Émile Baudot]] (died [[1903 in science|1903]]), French [[telegraph]] engineer.
* November 14 – [[Ulisse Dini]] (died [[1918 in science|1918]]), Italian mathematician.

==Deaths==
* [[January 11]] &ndash; [[Etheldred Benett]] (born [[1776 in science|1776]]), British geologist. 
* March 13 – [[John Frederic Daniell]] (born [[1790 in science|1790]]), English [[chemist]] and [[physicist]].
* March 18 – '[[Johnny Appleseed]]' (John Chapman) (born [[1774 in science|1774]]), American [[Plant nursery|nurseryman]].<ref>{{cite news|title=Obituaries|work=[[The News-Sentinel|The Fort Wayne Sentinel]]|volume=67|issue=81|date=22 March 1845}}</ref>
* April 10 – [[Thomas Sewall]] (born [[1786 in science|1786]]), American [[anatomist]].
* October 18 – [[Dominique, comte de Cassini]] (born [[1748 in science|1748]]), French [[astronomer]].
* [[Jean Henri Jaume Saint-Hilaire]] (born [[1772 in science|1772]]), French [[botanist]].

==References==
{{reflist}}

[[Category:1845 in science| ]]
[[Category:19th century in science]]
[[Category:1840s in science]]