1761 in science

Astronomy

• June 6 – The first transit of Venus since Edmond Halley suggested that its observation could determine the distance from the Earth to the Sun. Joseph-Nicolas Delisle set up a 62-station network for observing the transit. Those taking part included:
• * Nathaniel Bliss at the Royal Greenwich Observatory near London
• * César Cassini de Thury in Vienna
• * Jean-Baptiste Chappe d'Auteroche in Tobolsk, Siberia
• * Jeremiah Dixon and Charles Mason in Cape Town, South Africa
• * Maximilian Hell in Vardø, Norway
• * Joseph de Lalande in Paris
• * Tobias Mayer in Göttingen
• * Nevil Maskelyne on Saint Helena
• * Alexandre Pingré on Rodrigues Island
• * John Winthrop in St. John's, Newfoundland
• * Mikhail Lomonosov, who finds the first evidence that the planet has an atmosphere

Botany

• Louis Gérard publishes Flora Gallo-Provincialis, the first flora arranged according to natural classification.

  Chemistry

• Johan Gottschalk Wallerius publishes his pioneering work in agricultural chemistry, Agriculturae fundamenta chemica.

  Mathematics

• Johann Heinrich Lambert gives a proof that π is irrational.

  Medicine

• Leopold Auenbrugger publishes Novum ex Percussione Thoracis Humani Interni Pectoris Morbos Detegendi in Vienna, for the first time advocating percussion of the chest as a diagnostic measure.
• Giovanni Battista Morgagni publishes De Sedibus et causis morborum per anatomem indagatis, a pioneering work of anatomical pathology.
• Samuel-Auguste Tissot publishes Avis au peuple sur sa santé, a popular text of the century.

  Veterinary medicine

• August 4 – Claude Bourgelat founds the first veterinary school, in Lyon; courses begin in 1762.

  Technology

• Opening of Matthew Boulton's Soho Manufactory in England.

  Awards

• Copley Medal: not awarded

  Births

• January 17 – James Hall, Scottish geologist and physicist.
• January 19 – Pierre Marie Auguste Broussonet, French naturalist and physician.
• February 1 – Christiaan Hendrik Persoon, South African-born Pomeranian/Dutch mycologist.
• February 4 – Blasius Merrem, German zoologist.
• June 7 – John Rennie, Scottish-born civil engineer.
• October 27 – Matthew Baillie, Scottish-born pathologist.
• November 30 – Smithson Tennant, English chemist.
• December 21 – Jean-Louis Pons, French astronomer.
• December 25 – William Gregor, Cornish mineralogist.

  Deaths

• January 4 – Stephen Hales, English physiologist and clergyman.
• March 22 – Pierre Fauchard, French physician and "father of modern dentistry".
• April 7 – Thomas Bayes, English mathematician.
• May 14 – Thomas Simpson, British mathematician.
• November – Giovanni Poleni, Italian mathematician and physicist.
• November 30 – John Dollond, English optician.