1870 in science

Biology

• January 18 – Gerhardt Krefft first describes the Queensland lungfish, in The Sydney Morning Herald.
• Charles Valentine Riley confirms Phylloxera as the cause of the Great French Wine Blight.

  Chemistry

• Norman Lockyer and Edward Frankland propose that the gas detected in solar observations should be called 'helium'.

  Ecology

• Introduced rabbits reach the New South Wales border in Australia.

  Mathematics

• Felix Klein constructs a model for hyperbolic geometry establishing its self-consistency and the logical independence of Euclid's fifth postulate.
• W. Stanley Jevons publishes the popular textbook Elementary Lessons on Logic.

  Medicine

• Louis Pasteur and Robert Koch establish the germ theory of disease.
• Henry Maudsley publishes his lectures on Body and Mind: an Inquiry into their Connection and Mutual Influence.
• Frances Morgan becomes the first British woman to receive a Doctor of Medicine degree from a European university, the University of Zurich.

  Meteorology

• November 1 – In the United States, the newly created Weather Bureau makes its first official meteorological forecast: "High winds at Chicago and Milwaukee... and along the Lakes".

  Paleontology

• Eustreptospondylus oxoniensis juvenile dinosaur fossil found in Summertown, Oxford.

  Physics

• Rudolf Clausius proves the scalar virial theorem.

  Psychology

• Ludimar Hermann observes the Hermann grid illusion.

  Technology

• February 26 – The Beach Pneumatic Transit subway in New York City is opened.
• March 8 – Joy valve gear for steam locomotives is patented in the United Kingdom by David Joy.
• August 2 – Official opening of the Tower Subway beneath the River Thames in London, first use of the cylindrical wrought iron tunnelling shield devised by Peter W. Barlow and James Henry Greathead and of a permanent tunnel lining of cast iron segments.
• Svend Foyn receives a Norwegian patent for the grenade harpoon cannon for whaling.
• Henry R. Heyl receives a United States patent for a magic lantern movie projector.
• A practical stock ticker is introduced by Thomas Edison.
• First known use of weapons for anti-aircraft warfare, at Paris during the Franco-Prussian War.

  Institutions

• Ellen Swallow Richards becomes the first woman admitted to study at the Massachusetts Institute of Technology.
• December 20 – Missouri University of Science and Technology established as the Missouri School of Mines and Metallurgy.

  Awards

• Copley Medal: James Prescott Joule
• Wollaston Medal for geology: Gerard Paul Deshayes

  Births

• January 9 – Joseph Strauss, American bridge engineer.
• January 13 – Ross Granville Harrison, American physiologist.
• February 7 – Alfred Adler, Austrian psychotherapist.
• March 17 – Horace Donisthorpe, English entomologist.
• May 20 – Arthur Korn, German inventor.
• May 27 – Anna Stecksén, Swedish scientist, physician and pathologist.
• June 21 – Clara Immerwahr, German chemist.
• August 25 – Mihran Kassabian, American radiologist.
• October 23 – George Newman, English public health physician.

  Deaths

• January 25 – Janet Taylor, English mathematician and navigational instrument maker.
• March 9 – 'Granny' Maria Ann Smith, English-born Australian horticulturalist.
• March 12 – Charles Xavier Thomas, French inventor of the first mass-produced calculator.
• July 12 – Alexander Henry Haliday, Anglo Irish entomologist.
• November 14 – Karl Weltzien, German inorganic chemist.
• December 27 – Nikolai N. Kaufman, Russian botanist.