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

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

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

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

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

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

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