1774 in science

Astronomy

• Johann Elert Bode discovers the galaxy Messier 81.
• Lagrange publishes a paper on the motion of the nodes of a planet's orbit.

  Biology

• Italian physicist Abbé Bonaventura Corti publishes Osservazioni microscopiche sulla tremella e sulla circulazione del fluido in una pianta acquajuola in Lucca, including his discovery of cyclosis in plant cells.
• French physician Antoine Parmentier publishes Examen chymique des pommes de terres in Paris, analysing the nutritional value of the potato.

  Chemistry

• August 1 – Joseph Priestley, working at Bowood House, Wiltshire, England, isolates oxygen in the form of a gas, which he calls "dephlogisticated air".
• Antoine Lavoisier publishes his first book, a literature review on the composition of air, Opuscules physiques et chimiques.
• Carl Wilhelm Scheele discovers "dephlogisticated muriatic acid", manganese and barium.

  Exploration

• Second voyage of James Cook
• * June 16/17 – English explorer Captain Cook becomes the first European to sight Palmerston Island in the Pacific Ocean.
• * September 4 – Cook becomes the first European to sight the island of New Caledonia in Melanesia.
• * October 10 – Cook becomes the first European to sight Norfolk Island in the Pacific Ocean, uninhabited at this date.

  Mathematics

• P.-S. Laplace publishes Mémoire sur la probabilité des causes par les événements, including a restatement of Bayes' theorem.

  Medicine and physiology

• William Hunter's Anatomia uteri humani gravidi tabulis illustrata | The Anatomy of the Human Gravid Uterus exhibited in figures is published by John Baskerville in Birmingham, England.
• Sugita Genpaku's Kaitai Shinsho, based on a Dutch publication, is published with illustrations in Japan, the first modern anatomy textbook produced there.

  Physics

• The Schiehallion experiment is carried by Nevil Maskelyne out to determine the mean density of the Earth.

  Technology

• John Wilkinson patents a method for boring cannon from the solid, subsequently utilised for accurate boring of steam engine cylinders.
• Jesse Ramsden produces an advanced circular dividing engine with the support of the Board of Longitude.

  Awards

• Copley Medal: Not awarded

  Births

• April 21 – Jean-Baptiste Biot, French physicist.
• April 24 – Jean Marc Gaspard Itard, French otorhinolaryngologist.
• April 28 – Francis Baily, English astronomer.
• May 7 – Francis Beaufort, Irish-born hydrographer.
• May 28 – Edward Howard, English chemist.
• August 18 – Meriwether Lewis, American explorer.
• September 26 – John Chapman, American nurseryman.
• November 12 – Charles Bell, Scottish-born anatomist.
• December 12 – William Henry, English chemist.

  Deaths

• February 4 – Charles Marie de La Condamine, French geographer
• May 1 – William Hewson, English surgeon, anatomist and physiologist, "father of haematology"
• July 9 – Anna Morandi Manzolini, Italian anatomist