1873 in science

• Jacobus Henricus van 't Hoff and Joseph Achille Le Bel, working independently, develop a model of chemical bonding that explains the chirality experiments of Pasteur and provides a physical cause for optical activity in chiral compounds{{cite web|title=Jacobus Henricus van't Hoff|url=https://www.sciencehistory.org/historical-profile/jacobus-henricus-van%E2%80%99t-hoff|website=Science History Institute |accessdate=21 March 2018|date=June 2016}}{{cite book|last1=Bowden|first1=Mary Ellen|title=Chemical achievers : the human face of the chemical sciences|url=https://archive.org/details/chemicalachiever0000bowd|url-access=registration|date=1997|publisher=Chemical Heritage Foundation|location=Philadelphia, PA|isbn=9780941901123|chapter=Jacobus Henricus van't Hoff|pages=[https://archive.org/details/chemicalachiever0000bowd/page/94 94–95]}}

• The Austro-Hungarian North Pole Expedition discovers Franz-Josef Land

• Charles Hermite proves that the mathematical constant e is a transcendental number{{cite book|first=Tony|last=Crilly|title=50 Mathematical Ideas you really need to know|location=London|publisher=Quercus|year=2007|isbn=978-1-84724-008-8}}
• Henri Brocard introduces the Brocard points, Brocard triangle and Brocard circle"Etudes d'un nouveau cercle du plan du triangle". Paper to l'Association française pour l'avancement des sciences.{{cite journal|first=Laura|last=Guggenbuhl|authorlink= Laura Guggenbühl |title=Henri Brocard and the Geometry of the Triangle|journal=The Mathematical Gazette|location=London|publisher=Mathematical Association|volume=37|issue=322 |pages=241–243|jstor=3610034 |date=December 1953|doi=10.1017/S0025557200027558}}

• September 15 – agreement for establishment of the International Meteorological Organization.{{citation needed|date=May 2025}}

• February 20 – English electrical engineer Willoughby Smith publishes his discovery of the photoconductivity of the element selenium{{cite journal|doi=10.1038/007303e0|title=Effect of Light on Selenium During the Passage of an Electric Current|year=1873|journal=Nature|volume=7|issue=173|page=303|bibcode = 1873Natur...7R.303. |doi-access=free}}
• June 14 – Johannes Diderik van der Waals defends his thesis, [http://www.scs.uiuc.edu/~mainzv/exhibit/vanderwaals.htm Over de Continuiteit van den Gas en Vloeistoftoestand] (On the continuity of the gaseous and liquid state) at Leiden University; in this, he introduces the concepts of molecular volume and molecular attraction; gives a semi-quantitative description of the phenomena of condensation and critical temperatures; and derives the van der Waals equation{{cite journal|authorlink=James Clerk Maxwell|last=Clerk-Maxwell|first=J.|year=1874|title=Van der Waals on the Continuity of the Gaseous and Liquid States|journal=Nature|volume=10|pages=477–480|doi=10.1038/010477a0|bibcode=1874Natur..10..477C|issue=259|url=https://zenodo.org/record/1429215/files/article.pdf}}
• September 22 – James Clerk Maxwell delivers a discourse on molecules to the British Association for the Advancement of Science meeting in Bradford{{cite journal|first=J.|last=Clerk-Maxwell|title=Molecules|journal=Nature|doi=10.1038/008437a0|volume=8|issue=204|date=25 September 1873|pages=437–41|bibcode=1873Natur...8..437.|doi-access=free}} Also digitised at [http://www.victorianweb.org/science/maxwell/molecules.html The Victorian Web]. [https://web.archive.org/web/20120510161223/http://www.victorianweb.org/science/maxwell/molecules.html Archived] 2012-02-23.
• December – J. Willard Gibbs describes the principle of Gibbs free energy{{cite journal|first=J. W.|last=Gibbs|title=A Method of Geometrical Representation of the Thermodynamic Properties of Substances by Means of Surfaces|journal=Transactions of the Connecticut Academy of Arts and Sciences|volume=2|year=1873|pages=382–404}}
• James Clerk Maxwell's A Treatise on Electricity and Magnetism first presents the partial differential equations known as Maxwell's equations which form the foundation of classical electrodynamics, optics and electric circuits
• Frederick Guthrie is the first to report observing thermionic emission{{cite book|url=https://books.google.com/books?id=PrbOIoMnxnwC&pg=PA196|title=The emission of positive ions by hot metals|first=Owen|last=Richardson|year=1921|accessdate=2009-07-11|isbn=978-1-929148-10-3}}

• June 18 – Alice Vickery passes the Royal Pharmaceutical Society's examination, becoming the first qualified female pharmacist in the United Kingdom{{cite web|url=http://www.rpharms.com/women-pharmacists-before-the-20th-century/alice-vickery.asp|title=Alice Vickery|publisher=Royal Pharmaceutical Society|website=www.rpharms.com|accessdate=2013-07-25|archive-date=2016-03-07|archive-url=https://web.archive.org/web/20160307083353/http://rpharms.com/women-pharmacists-before-the-20th-century/alice-vickery.asp|url-status=dead}}
• Mycobacterium leprae, the causative agent of leprosy, is discovered by Norwegian physician Gerhard Armauer Hansen. It is the first bacterium to be identified as pathogenic in humans{{cite journal|last=Hansen|first=G. H. A.|title=Undersøgelser Angående Spedalskhedens Årsager|trans-title=Investigations concerning the etiology of leprosy|journal=Norsk Mag. Laegervidenskaben|year=1874|volume=4|pages=1–88|language=Norwegian}}{{cite journal|last=Irgens|first=L.|title=The discovery of the leprosy bacillus|journal=Tidsskr. Nor. Laegeforen.|volume=122|issue=7|pages=708–9|year=2002|pmid=11998735}}
• English allergist Charles Harrison Blackley publishes Experimental Researches on the Causes and Nature of Catarrhus aestivus
• Camillo Golgi first publishes a demonstration of Golgi's method{{cite book|title=Origins of Neuroscience: a history of explorations into brain function|last=Finger|first=Stanley|publisher=Oxford University Press|year=1994|isbn=9780195146943|page=45|oclc=27151391|quote=In 1873, Golgi published the first brief but "adequate" picture of la reazione nera (the black reaction), which showed the whole nerve cell, including its cell body, axon, and branching dendrites.}}

• May 20 – Jacob W. Davis and Levi Strauss receive United States patent#139121 for using copper rivets to strengthen the pockets of denim jeans
• Carl von Linde installs his first commercial refrigeration system, built by Maschinenfabrik Augsburg for the Spaten Brewery and using dimethyl ether as the refrigerant
• Christopher Miner Spencer introduces the fully automatic turret lathe{{cite book|authorlink=L. T. C. Rolt|first=L. T. C.|last=Rolt|title=A Short History of Machine Tools|publisher=MIT Press|location=Cambridge, Massachusetts|year=1965|page=169}}

• Copley Medal: Hermann Helmholtz{{cite web |title=Copley Medal {{!}} British scientific award |url=https://www.britannica.com/science/Copley-Medal |website=Encyclopedia Britannica |accessdate=23 July 2020 |language=en}}
• Wollaston Medal for geology: Philip de Malpas Grey Egerton

• February 11 – Louis Charles Christopher Krieger (died 1940), American mycologist
• February 12 – Barnum Brown (died 1963), American paleontologist
• March 5 – Thomas Harrison Montgomery, Jr. (died 1912), American zoologist and cell biologist
• April 25 – Félix d'Herelle (died 1949), French-Canadian microbiologist, a co-discoverer of bacteriophages
• June 28 – Alexis Carrel (died 1942), French surgeon, biologist and winner of a Nobel Prize in Physiology or Medicine
• June 30 – Friedrich Karl Georg Fedde (died 1942), German botanist
• July 7 – Sándor Ferenczi (died 1933), Hungarian psychoanalyst
• October 4 – Dimitrie Pompeiu (died 1954), Romanian mathematician
• October 9 – Karl Schwarzschild (died 1916), German astronomer and physicist

• January 27 – Adam Sedgwick (born 1785), English geologist
• February 1 – Matthew Fontaine Maury (born 1806), American oceanographer
• April 18 – Justus von Liebig (born 1803), German chemist
• March 10 – John Torrey (born 1796), American botanist
• March 30 – Bénédict Morel (born 1809), French psychiatrist
• September 15 – Alexei Pavlovich Fedchenko (born 1844), Russian naturalist
• September 24 – John Thurnam (born 1810), English psychiatrist and ethnologist
• October 17 – Robert McClure (born 1807), British Arctic explorer
• December 14 – Louis Agassiz (born 1807), Swiss-American zoologist and geologist

{{Reflist}}

Category:19th century in science

Category:1870s in science