1893 in science

The year 1893 in science and technology involved some significant events, listed below.

Biology

 * July 11 – Kōkichi Mikimoto, in Japan, develops the method to seed and grow cultured pearls.
 * Henry Luke Bolley discovers a method of treating smut with formaldehyde.

Chemistry

 * Hans Goldschmidt discovers the thermite reaction.
 * Nagai Nagayoshi synthesizes methamphetamine from ephedrine.
 * Alfred Werner discovers the octahedral structure of cobalt complexes, thus establishing the field of coordination chemistry.

Earth sciences

 * Eduard Suess postulates the former existence of the Tethys Sea.

Exploration

 * Mary Kingsley lands in Sierra Leone on the first of her journeys through Africa in the interests of anthropology and natural history.

Mathematics

 * J. J. Sylvester poses what becomes known as the Sylvester–Gallai theorem in geometry.
 * Geometric Exercises in Paper Folding by T. Sundara Row is first published in Madras.

Medicine

 * July 9 – Daniel H. Williams completes the first successful open heart surgery.
 * October 5 – Johns Hopkins Medical School opens in the United States.
 * Emil Kraepelin introduces the concept of dementia praecox in the classification of mental disorders, distinguishing it from mood disorder in his Lehrbuch der Psychiatrie (4th edition).
 * Ádám Politzer describes otosclerosis for the first time.
 * Vladimir Bekhterev describes Ankylosing spondylitis.

Physics

 * Wilhelm Wien formulates Wien's displacement law.

Technology

 * January 2 – Webb C. Ball introduces railroad chronometers which become the general railroad timepiece standards in North America.
 * February 1 – Thomas Edison finishes construction of the first motion picture studio in West Orange, New Jersey.
 * February 11 – János Csonka and Donát Bánki apply for a patent for the carburetor in Hungary.
 * February 23 – Rudolf Diesel receives a patent for the diesel engine. In this year he also publishes his treatise Theorie und Konstruktion eines rationellen Wärmemotors zum Ersatz der Dampfmaschine und der heute bekannten Verbrennungsmotoren.
 * February 28 – Edward Goodrich Acheson patents the method for making the abrasive silicon carbide powder.
 * May 9 – Edison's 1½ inch system of Kinetoscope is first demonstrated in public at the Brooklyn Institute.
 * May – William Scherzer (dies July 20) files a patent for his design of rolling lift bridge.
 * June 21 – The first Ferris Wheel opens to the public at the World's Columbian Exposition in Chicago.
 * July 12 – Prototype of Diesel's Motor 250/400 (150/400) completed; first run August 10 (on petrol).
 * July 25 – Completion of the Corinth Canal in Greece.
 * August 17 – Wilhelm Maybach patents the spray nozzle carburetor in France.
 * Refinery for Pacific Coast Borax Company in Alameda, California, designed by Ernest L. Ransome, is the first major reinforced concrete building in the United States.
 * The first sousaphone is built by James Welsh Pepper at the request of bandmaster John Philip Sousa in the United States.

Awards

 * Copley Medal: George Gabriel Stokes
 * Wollaston Medal for Geology: Nevil Story Maskelyne

Births

 * February 3 – Gaston Julia (died 1978), French mathematician.
 * February 24 – Tokushichi Mishima (died 1975), Japanese inventor and metallurgist.
 * April 29 – Harold Urey (died 1981), American winner of the Nobel Prize in Chemistry.
 * April 30 – Roy Chadwick (died 1947), English aircraft designer.
 * June 13 – Alan A. Griffith (died 1963), English stress engineer.
 * August 5 – Sydney Camm (died 1966), English aircraft designer.
 * August 15 – Leslie Comrie (died 1950), New Zealand astronomer and computing pioneer.
 * August 24 – Haim Ernst Wertheimer (died 1978), German Jewish biochemist.
 * August 25 – Henry Trendley Dean (died 1962), American dental researcher.
 * September 16 – Albert Szent-Györgyi (died 1986), Hungarian physiologist, winner of the Nobel Prize in Physiology or Medicine.
 * October 23 – Ernst Öpik (died 1985), Estonian astronomer and astrophysicist.
 * November 3 – Edward Adelbert Doisy (died 1986), American biochemist, winner of the Nobel Prize in Physiology or Medicine.
 * December 3 – Wilhelm Pelikan (died 1981), Austrian chemist.
 * December 14 – Alf Lysholm (died 1973), Swedish mechanical engineer.
 * December – Eugène Gabritschevsky (died 1979), Russian biologist and artist.

Deaths

 * January 2 – John Obadiah Westwood (born 1805), English entomologist.
 * January 7 – Jožef Stefan (born 1835), Slovenian physicist and mathematician.
 * March 3 – Orlando Whistlecraft (died 1810), English meteorologist.
 * August 16 – Jean-Martin Charcot (born 1825), French neurologist.
 * September 1 – Leonard Jenyns (born 1800), English natural historian.
 * November 6 - Justin Benoît, (born 1813), French surgeon and anatomist
 * December 4 – John Tyndall (born 1820), British physicist.
 * December 6 – Rudolf Wolf (born 1816), Swiss astronomer.
 * December 25 – Marie Durocher (born 1809), Brazilian obstetrician and physician.
 * December 28 – Richard Spruce (born 1817), English botanist.