# 1803 in science

"none" is preferred when the title is sufficiently descriptive; see [[WP:SDNONE]]
The year 1803 in science and technology involved some significant events.

## Astronomy

* April 26 – A meteorite shower falls on L'Aigle in Normandy; Jean Baptiste Biot demonstrates that it is of extraterrestrial origin.

## Botany

* Publication (posthumously) of André Michaux's Flora Boreali-Americana in Paris, the first flora of North America.
* University of Tartu Botanical Gardens established.

## Chemistry

* January 1 – William Henry's formulation of his law on the solubility of gases first published.
* September 3 – English scientist John Dalton starts using symbols to represent the atoms of different chemical elements.
* October 21 – John Dalton's atomic theory and list of molecular weights first made known, at a lecture in Manchester.
* William Hyde Wollaston discovers the chemical element rhodium.
* Smithson Tennant discovers the chemical elements iridium and osmium.
* Cerium is discovered in Bastnäs (Sweden) by Jöns Jakob Berzelius and Wilhelm Hisinger, and independently in Germany by Martin Heinrich Klaproth.
* Claude Louis Berthollet publishes Essai de statique chimique in Paris.

## Exploration

* June 9 – Matthew Flinders completes the first known circumnavigation of Australia.

## Mathematics

* Gian Francesco Malfatti presents his conjecture regarding Malfatti circles.

## Medicine

* Jean Marc Gaspard Itard first recognises pneumothorax.
* Dr Thomas Percival of Manchester publishes his Medical Ethics; or, a Code of Institutes and Precepts, Adapted to the Professional Conduct of Physicians and Surgeons, coining the expression medical ethics.

## Meteorology

* Luke Howard publishes the basis of the modern classification and nomenclature of clouds.

## Technology

* Robert Ransome invents the self-sharpening chilled cast-iron ploughshare in Ipswich, England.
* The first Fourdrinier continuous papermaking machine is installed in Hertfordshire, England.

## Transport

* January 4 – William Symington demonstrates his Charlotte Dundas, the "first practical steamboat", in Scotland.
* July 26 – The Surrey Iron Railway, a wagonway between Wandsworth and Croydon, is opened, being the first public railway line in England.
* Thomas Telford begins work on construction of the Caledonian Canal and improving roads in Scotland.

## Awards

* Copley Medal: Richard Chenevix

## Births

* February 26 – Arnold Adolph Berthold, German physiologist (died 1861)
* February 28 – Christian Heinrich von Nagel, German geometer (died 1882)
* April 1 – Miles Joseph Berkeley, English cryptogamist (died 1889)
* May 12 – Justus von Liebig, German chemist (died 1873)
* May 24 – Charles Lucien Bonaparte, French naturalist (died 1857)
* June 8 – Amalia Assur, Swedish dentist (died 1889)
* July 31 – John Ericsson, Swedish-born mechanical engineer and inventor (died 1889)
* October 3 – John Gorrie, American physician and inventor (died 1855)
* October 6 – Heinrich Wilhelm Dove, Prussian physicist and climatologist (died 1879)
* October 16 – Robert Stephenson, English railway engineer (died 1859)
* November 29 – Christian Doppler, Austrian mathematician and discoverer of the Doppler effect (died 1853)
* December 21 – Joseph Whitworth, English mechanical engineer (died 1887)
* Choe Han-gi, Korean philosopher of science (died 1877)

## Deaths

* May 8 – John Joseph Merlin, Liège-born English inventor (born 1735)
* October 14 – Ami Argand, Genevan physicist and chemist (born 1750)