1776 in science

Astronomy

• Lagrange publishes a paper on the stability of planetary orbits.

Botany

• William Withering publishes The Botanical Arrangement of all the Vegetables Naturally Growing in Great Britain, the first flora in English based on Linnaean taxonomy.

Chemistry

• James Keir begins publication of A Dictionary of Chemistry in London, a translation into English of Pierre Macquer's Dictionnaire de chymie.

Exploration

• July 12 – Captain James Cook sets off from Plymouth, England, in HMS Resolution on his third voyage, to the Pacific Ocean and the Arctic.

Geology

• James Keir suggests that some rocks, such as those at the Giant's Causeway, might have been formed by the crystallisation of molten lava.

Mathematics

• Jean Baptiste Meusnier discovers the helicoid and announces Meusnier's theorem.

Medicine

• November 30 – Sir John Pringle presents "A discourse upon some late improvements of the means for preserving the health of mariners" to the Royal Society of London, commending and publicising Captain Cook's methods for prevention of scurvy at sea.
• Publication of observations of epidemic diseases in Normandy, based on Hippocrates' table of epidemics by Louis Lépecq de La Clôture.

Technology

• June–July – Claude-François-Dorothée, marquis de Jouffroy d'Abbans, demonstrates his steamboat Palmipède on the Doubs (river) in France.
• John Wilkinson installs a steam blowing engine at his ironmaking furnace in Willey, Shropshire, England.

Awards

• Copley Medal: James Cook

Births

• February 4 – Gottfried Reinhold Treviranus, German naturalist
• February 14 – Christian Gottfried Daniel Nees von Esenbeck, German botanist
• March 27 – Charles-François Brisseau de Mirbel, French botanist and politician
• April 1 – Sophie Germain, French mathematician
• May 17 – Amos Eaton, American naturalist and pioneer of science education
• June 1 – Giuseppe Zamboni, Italian Catholic priest and physicist
• June 12 – Karl Friedrich Burdach, German physiologist
• July 16
• * Ludwig Heinrich Bojanus, German physician and naturalist
• * Johann Georg von Soldner, German physicist
• July 22 – Etheldred Benett, English geologist
• July 26 – Pierre Fouquier, French physician
• August 2 – Friedrich Stromeyer, German chemist, discoverer of cadmium
• August 6 – Amedeo Avogadro, Piedmontese chemist
• October 4 – Mariano Lagasca, Spanish botanist
• October 13 – Peter Barlow, English mathematician
• November 14 – Henri Dutrochet, French physician
• November 18 - Mauro Ruscóni, Italian physician and zoologist
• December 3 – Nicolas Charles Seringe, French physician and botanist
• December 31 – Johann Spurzheim, German physician

Deaths

• February 18 – Lady Anne Monson, English-born botanist
• June 13 – William Battie, English psychiatrist
• June 20 – Benjamin Huntsman, English inventor and manufacturer
• November 17 – James Ferguson, Scottish astronomer