1869 in science

The year 1869 in science and technology involved some significant events, listed below.

Events

 * November 4 – The first issue of scientific journal Nature is published in London, edited by Norman Lockyer.

Chemistry

 * March 6 – Dmitri Mendeleev makes a formal presentation of his periodic table to the Russian Chemical Society.
 * June 15 – John Wesley Hyatt patents celluloid, in Albany, New York.
 * July 15 – Hippolyte Mège-Mouriès files a patent for margarine (as oleomargarine) in France as a beef tallow and skimmed milk substitute for butter.
 * German chemist Lothar Meyer makes a formal presentation of the revised and expanded version of his independently-created 1864 periodic table, „Die Natur der chemischen Elemente als Funktion ihrer Atomgewichte".
 * Publication of Adolphe Wurtz's Dictionnaire de chimie pure et appliquée begins in Paris.

Life sciences

 * April 6 – The American Museum of Natural History is founded in New York.
 * June 24 – Sea Birds Preservation Act passed in the United Kingdom, preventing killing of designated species during the breeding season, the first Act to offer any protection to British wild birds.
 * Paul Langerhans discovers the pancreatic islets.
 * Friedrich Miescher discovers deoxyribonucleic acid (DNA) in the pus of discarded surgical bandages. Found in the nuclei of cells, Miescher names it "nuclein".
 * Neurasthenia is first published as a diagnosis in psychopathology by Michigan alienist E. H. Van Deusen of the Kalamazoo asylum followed a few months later by New York neurologist George Miller Beard.
 * French missionary and naturalist Père Armand David receives the skin of a giant panda from a hunter, the first time this species has become known to a Westerner; he also first describes a specimen of the "pocket handkerchief tree", which will be named in his honor as Davidia involucrata.
 * Alfred Russel Wallace publishes The Malay Archipelago.

Mathematics

 * W. Stanley Jevons publishes The Substitution of Similars and has a "Logic Piano" constructed to work out problems in symbolic logic.
 * Hermann Schwarz devises Schwarz–Christoffel mapping.

Technology

 * Approximate date – Henry Christopher Mance develops a practical military heliograph in the British Raj.

Awards

 * Copley Medal: Henri Victor Regnault
 * Wollaston Medal for Geology: Henry Clifton Sorby

Births

 * February 14 – C. T. R. Wilson (died 1959), Scottish physicist and meteorologist, recipient of the Nobel Prize in Physics.
 * February 27 – Alice Hamilton (died 1970), American physician.
 * April 8 – Harvey Cushing (died 1939), American neurosurgeon.
 * April 17 – Robert Robertson (died 1949), Scottish-born chemist.
 * June 19 – Christopher Addison (died 1951), English anatomist and politician.
 * July 18 – Maria von Linden (died 1936), German bacteriologist and zoologist.
 * August 23 – Robert Gunther (died 1940), English historian of science.
 * October 3 – Robert W. Paul (died 1943), English pioneer of cinematography.
 * November 23 – Valdemar Poulsen (died 1942), Danish audio engineer.
 * December 16 – Bertha Lamme (died 1943), American electrical engineer.
 * Helen Boyle (died 1957), British physician and psychologist.

Deaths

 * July 22 – John A. Roebling (born 1806), German American bridge engineer.
 * July 28 – Carl Gustav Carus (born 1789), German physiologist and landscape painter.
 * September 11 – Thomas Graham (born 1805), Scottish chemist.