1873 in science

The year 1873 in science and technology involved some significant events, listed below.

Chemistry

 * 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

Exploration

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

Mathematics

 * Charles Hermite proves that the mathematical constant e is a transcendental number
 * Henri Brocard introduces the Brocard points, Brocard triangle and Brocard circle

Meteorology

 * September 15 – agreement for establishment of the International Meteorological Organization

Physics

 * February 20 – English electrical engineer Willoughby Smith publishes his discovery of the photoconductivity of the element selenium
 * June 14 – Johannes Diderik van der Waals defends his thesis, 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
 * September 22 – James Clerk Maxwell delivers a discourse on molecules to the British Association for the Advancement of Science meeting in Bradford
 * December – J. Willard Gibbs describes the principle of Gibbs free energy
 * 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

Physiology and medicine

 * June 18 – Alice Vickery passes the Royal Pharmaceutical Society's examination, becoming the first qualified female pharmacist in the United Kingdom
 * 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
 * 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

Technology

 * May 20 – Jacob W. Davis and Levi Strauss receive United States patent 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

Awards

 * Copley Medal: Hermann Helmholtz
 * Wollaston Medal for geology: Philip de Malpas Grey Egerton

Births

 * 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

Deaths

 * 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