1865 in science

The year 1865 in science and technology involved some significant events, listed below.

Archaeology

 * John Lubbock publishes Pre-historic Times, as Illustrated by Ancient Remains, and the Manners and Customs of Modern Savages, including his coinage of the term Palæolithic.

Astronomy

 * Vassar College Observatory opens at Poughkeepsie, New York, with Maria Mitchell as its first director.

Chemistry

 * Friedrich Kekulé proposes a ring structure for benzene.
 * Adolf von Baeyer begins work on indigo dye, a milestone in modern industrial organic chemistry which revolutionizes the dye industry.
 * Johann Josef Loschmidt indirectly determines the number of molecules in a mole, later named the Avogadro constant.

Economics

 * William Stanley Jevons published his book the The Coal Question, which would form the scientific basis for the Jevons paradox.

Life sciences

 * Louis Pasteur shows that the air is full of bacteria.
 * Joseph Lister begins to experiment with antiseptic surgery in Glasgow using carbolic acid.
 * Max Schultze gives the first known description of the platelet.
 * Claude Bernard publishes Principes de Médecine experimentale.
 * February 8 & March 8 – Gregor Mendel reads his paper, Versuche über Pflanzenhybriden (Experiments on Plant Hybridization), at two meetings of the Natural History Society of Brünn in Moravia.
 * May 17 – Father Armand David first observes Père David's Deer in China.
 * June–August – Francis Galton formulates eugenics.
 * September – John Henry Walsh (writing as 'Stonehenge' in the magazine The Field) gives the first definition of a dog breed standard (for the pointer) based on physical form.
 * September 28 – Elizabeth Garrett Anderson obtains a licence from the Society of Apothecaries in London to practice medicine, the first woman to qualify as a doctor in the United Kingdom, and sets up in her own practice.

Physics

 * Rudolf Clausius gives the first mathematical version of the concept of entropy, and also names it.
 * James Clerk Maxwell publishes A Dynamical Theory of the Electromagnetic Field.

Technology

 * Aveling and Porter produce the world's first steam roller at Rochester in England.
 * Hermann Sprengel produces the Sprengel pump which is capable of creating a significant vacuum.

Awards

 * Copley Medal: Michel Chasles
 * Wollaston Medal in Geology: Thomas Davidson

Births

 * January 22 – Friedrich Paschen (died 1947), German physicist.
 * February 1 – Henry Luke Bolley (died 1956), American plant pathologist.
 * March 19 – William Morton Wheeler (died 1937), American entomologist.
 * March 31 – Anandi Gopal Joshi (died 1887), Indian physician.
 * April 28 – Charles W. Woodworth (died 1940), American entomologist.
 * June 27 – John Monash (died 1931), Australian civil engineer and General.
 * August 10 – Charles Close (died 1952), Jersey-born cartographer.
 * October 12 – Arthur Harden (died 1940), English biochemist, Nobel Prize in Chemistry recipient.
 * November 4 – Chevalier Jackson (died 1958), American laryngologist and pioneer of endoscopy.

Deaths

 * January 14 – Marie-Anne Libert (born 1782), Belgian botanist.
 * January 31 – Hugh Falconer (born 1808), British geologist, botanist, paleontologist and paleoanthropologist.
 * April 23 – Diego de Argumosa (born 1792), Spanish surgeon.
 * April 30 – Robert FitzRoy (born 1805), English admiral and meteorologist, suicide.
 * May 27 – Charles Waterton (born 1782), English naturalist and explorer.
 * July 25 – Dr. James Barry (born 1789-1799), Irish-born military surgeon.
 * August 12 – Sir William Jackson Hooker (born 1785), English botanist.
 * August 13 – Ignaz Semmelweis (born 1818), Hungarian physician, following restraint in insane asylum.
 * August 26 – Johann Franz Encke (born 1791), German astronomer.
 * August 29 – Robert Remak (born 1815), Polish/Prussian Jewish embryologist.
 * September 2 – Sir William Rowan Hamilton (born 1805), Irish mathematician, physicist and astronomer.
 * October 17 – Joseph-François Malgaigne (born 1806), French surgeon.