1843 in science

The year 1843 in science and technology involved some significant events, listed below.

Astronomy

• March 11–14 – Eta Carinae flares to become the second brightest star.
• February 5–April 19 – "Great March Comet" observed.
• December 21 – The first total solar eclipse of Saros 139 occurs over southern Asia.
• Heinrich Schwabe reports a periodic change in the number of sunspots: they wax and wane in number according to a ten-year cycle.

Chemistry

• Jean-Baptiste Dumas names lactose.^[1]
• Carl Mosander discovers the chemical elements Terbium and Erbium.^[2]
• John J. Waterston produces an account of the kinetic theory of gases.^[3]
• Alfred Bird produces single-acting baking powder.^[4]

Mathematics

• September –
  Bernoulli numbers, regarded as the world's first computer program.^[5][6][7]
• October 16 –
  quaternions and deduces that they are non-commutative.^[8]
• Arthur Cayley and James Joseph Sylvester found the algebraic invariant theory.
• John T. Graves discovers the octonions.
• Pierre-Alphonse Laurent
  discovers and presents the Laurent expansion theorem.

Physics

• James Prescott Joule experimentally finds the mechanical equivalent of heat.^[9]
• Ohm's acoustic law is proposed by German physicist Georg Ohm.

Physiology and medicine

• April–May – English surgeon Benjamin Brodie extracts a coin lodged in the bronchus of engineer Isambard Kingdom Brunel using novel methods.^[10]
• British surgeon
  hypnotism
  .
• puerperal fever is spread by lack of hygiene in physicians.^[11]

• March 25 – Completion of the Thames Tunnel, the first bored underwater tunnel in the world (engineer: Marc Isambard Brunel).^[12]
• July 19 – Launch of SS Great Britain, the first iron-hulled, propeller-driven ship to cross the Atlantic Ocean (designer: Isambard Kingdom Brunel).^[13]
• November 21 –
  sulphur in the United Kingdom
• The steam powered rotary printing press is invented by Richard March Hoe in the United States.^[14]
• Robert Stirling and his brother James convert a steam engine at a Dundee factory to operate as a Stirling engine.
• The first public
  telegraph line in the United Kingdom is laid between Paddington and Slough
  .
• Approximate date – Euphonium invented.

Publications

• October – Anna Atkins begins publication of Photographs of British Algae: Cyanotype Impressions, a collection of contact printed cyanotype photograms of algae which forms the first book illustrated with photographic images.^{[15][16][17][18]}

Awards

• Copley Medal: Jean-Baptiste Dumas^[19]
• Pierre Armand Dufrenoy

Births

• January 13 –
  neurologist.^[20]
• May 6 –
  G. K. Gilbert (died 1918), American geologist
  .
• June 12 – David Gill (died 1914), Scottish astronomer.
• June 23 –
  mineralogist
  .
• July 24 – William de Wiveleslie Abney (died 1920), English astronomer.
• August 17 –
  forensic scientist
  .
• November 30 – Martha Ripley (died 1912), American physician.^[21]
• December 11 – Robert Koch (died 1910), German physician, famous for the discovery of the tubercle bacillus (1882) and the cholera bacillus (1883) and for his development of Koch's postulates; awarded the Nobel Prize in Physiology or Medicine in 1905
• Adelaida Lukanina (died 1908), Russian chemist.

Deaths

• July 25 –
  waterproof fabric.^[22]
• August 10 –
  Irish American mathematician
  .
• September 11 – Joseph Nicollet (born 1786), French geographer, explorer, mathematician and astronomer.
• September 19 –
  Coriolis effect
  .
• September 30 –
  zoologist
  .
• November 16 –
  Anglo-Irish surgeon
  .