1789 in science

Anatomy

• Antonio Scarpa publishes Anatomicæ disquisitiones de auditu et olfactu, a classic treatise on the hearing and olfactory organs.

  Astronomy

• August 28 & September 17 – William Herschel discovers Saturn's moons Enceladus and Mimas, which he describes to the Royal Society of London on November 12.
• Maximilian Hell establishes the constellations Tubus Hershelli Major and Minor in honour of Herschel's discovery of Uranus.

  Botany

• Erasmus Darwin publishes his poem The Loves of the Plants, a popular rendering of Linnaeus' works.
• Antoine Laurent de Jussieu publishes , providing a basis for the system of natural classification of flowering plants largely still in use.

  Chemistry

• Antoine Lavoisier's Traité élémentaire de chimie presents a unified view of new theories of chemistry, containing a clear statement of the law of conservation of mass, defining the nature of elements and denying the existence of phlogiston. He also helps establish the scientific journal Annales de chimie which will still be published into the 21st century.
• German chemist Martin Heinrich Klaproth discovers the element Uranium while studying the mineral pitchblende.

  Exploration

• July 10 – Alexander Mackenzie reaches the Mackenzie River Delta.

  Mathematics

• The Slovene mathematician Jurij Vega presents his approximation of π to 140 decimal places of which the first 126 are correct, a feat not exceeded for more than half a century.

  Medicine

• February 4 – James Parkinson gives the first description of human injury from lightning strikes, in a paper read to the Medical Society of London.
• Andrew Duncan delivers the first lectures on forensic medicine in Britain, at the University of Edinburgh.

  Technology

• Rev. Dr. Edmund Cartwright patents his first practical power loom in England and designs a wool combing machine.
• William Wouldhave demonstrates a self-righting rescue lifeboat on the River Tyne in England.

  Zoology

• Swiss naturalist François Huber devises the "leaf hive" for the cultivation of honey bees.

  Awards

• Copley Medal: William Morgan

  Births

• February 26 – Eaton Hodgkinson, English structural engineer
• March 16 – Georg Ohm, German physicist
• August 21 – Augustin-Louis Cauchy, French mathematician
• September 28 – Richard Bright, English physician
• October 8 – William John Swainson, English naturalist
• October 25 – Heinrich Schwabe, German astronomer

  Deaths

• April 7 – Petrus Camper, Dutch comparative anatomist
• May 25 – Anders Dahl, Swedish botanist for whom the dahlia is named
• undated – Angélique du Coudray, French pioneer of modern midwifery