1775 in science

• The cheetah (Acinonyx jubatus) is described. ==Chemistry==

• May 25 – Joseph Priestley's account of his isolation of oxygen in the form of a gas ("dephlogisticated air") is read to the Royal Society of London. • Swedish chemist Torbern Bergman's '''' ("A Dissertation on Elective Attractions") is published, containing the largest tables of chemical affinity ever published. • Swedish chemist Carl Wilhelm Scheele produces the toxic cupric hydrogen arsenite pigment Scheele's green. ==Exploration==

• July 30 – 3-year second voyage of James Cook completed, the first eastabout global circumnavigation, during which the Antarctic Circle has been crossed three times, Terra Australis shown to be a myth, and Larcum Kendall's K1 chronometer demonstrated to be a reliable timekeeper for the purpose of calculating longitude. ==Mathematics==

• Lagrange's ''Recherches d'Arithmétique'' develops a general theory of binary quadratic forms. • First Stanhope Demonstrator, a mechanical device to demonstrate and solve problems in logic, is produced by English aristocrat Charles Stanhope, 3rd Earl Stanhope. ==Medicine==

• English surgeon Percivall Pott finds the first occupational link to cancer, contributing to the science of epidemiology. • German physician Melchior Adam Weikard anonymously publishes the textbook Der Philosophische Arzt including the earliest description of symptoms resembling attention deficit hyperactivity disorder. ==Natural history==

• February 21 – La Specola, Florence's Museum of Zoology and Natural History, opens to the public. • Johan Christian Fabricius publishes his ''''. • Peter Forsskål's ' (containing early observations on bird migration) and ' are published posthumously, edited by Carsten Niebuhr. ==Technology==

• May 22 – James Watt's 1769 steam engine patent is extended to June 1800 by Act of Parliament of Great Britain and the first engines are built under it. • Jacques-Constantin Périer operates a paddle steamer on the Seine, but it proves to be underpowered. • Alexander Cumming patents the S-trap in London, laying the foundations for the modern flush toilet. • Edinburgh confectioner Charles Spalding devises improvements to the diving bell, adding a system of balance-weights. • Pierre-Simon Girard, age 10, invents a water turbine. • December 30 – John Arnold takes out his first patent for improvements in the construction of marine chronometers in Britain, including the first for a compensation balance. • Approximate date – Thomas Mudge invents the detached lever escapement for clocks and watches. • French Academy of Sciences made the statement that the academy "will no longer accept or deal with proposals concerning perpetual motion." ==Awards==

• Copley Medal: Nevil Maskelyne ==Births==

• January 22 – André-Marie Ampère, French physicist (died 1836) • February 9 – Farkas Bolyai, Hungarian mathematician (died 1856) • May 10 – William Phillips, English geologist (died 1828) • July 23 – Étienne-Louis Malus, French physicist and mathematician] (died 1812) • September 30 – Robert Adrain, Irish-born mathematician (died 1843) • November 19 – Johann Karl Wilhelm Illiger, German entomologist and zoologist (died 1813) • December 21 – Julien-Joseph Virey, French anthropologist, naturalist and physician (died 1846) ==Deaths==

• March 3 – Richard Dunthorne, English astronomer (born 1711) • May 1 – Israel Lyons, English mathematician and botanist (born 1739; died of measles) • October 25 – Johan Maurits Mohr, Dutch astronomer (born 1716) ==References==