1790 in science

Astronomy

• Armagh Observatory, founded in Ireland by Richard Robinson, 1st Baron Rokeby, Archbishop of Armagh, begins to function.

  Biology

• English ornithologist John Latham publishes his Index Ornithologicus, including a scientific description of the black swan.
• English botanical illustrator James Sowerby begins publication of his English Botany, with text by James E. Smith.

  Chemistry

• July 31 – Samuel Hopkins of Vermont is granted a patent for a potash production technique, the first issued under the 1st United States Congress's Patent Act of 1790.
• Publication in Montpellier of Jean-Antoine Chaptal's Élémens de chimie, in which he coins the word nitrogen.
• Adair Crawford, working with William Cruickshank, proposes the existence of the alkaline earth metal located near Strontian in Scotland which will later be isolated at strontium.

  Technology

• January 30 – Henry Greathead's Original rescue life-boat is tested on the River Tyne in England.

  Awards

• Copley Medal: Not awarded

  Births

• February 3 – Gideon Mantell, English paleontologist
• March 12 – John Frederic Daniell, English chemist and physicist
• May 23 – Jules Dumont d'Urville, French explorer
• May 30 – John Herapath, English physicist
• July 1 – George Everest, Welsh surveyor and geographer
• October 25 – Robert Stirling, Scottish inventor
• November 17 – August Ferdinand Möbius, German mathematician
• December 9 – Friederike Lienig, Latvian entomologist
• December 19 – William Edward Parry, English Arctic explorer

  Deaths

• February 5 – William Cullen, Scottish physician and chemist
• March 22 – Anthony Addington, English physician
• April 17 – Benjamin Franklin, American statesman and polymath, known for his experiments with electricity
• July 17 – Johann II Bernoulli, Swiss mathematician