*See also:* 1824 in science, other events of 1825, 1826 in science and the list of years in science.

Table of contents |

2 Chemistry 3 Mathematics 4 Paleontology 5 Technology 6 Awards 7 Births 8 Deaths |

- Pierre-Simon Laplace completes his study of gravitation, the stability of the solar system, tides, the precession of the equinoxes, the libration of the Moon, and Saturn's rings in
*Mecanique Celeste*

- Michael Faraday isolates benzene
- Hans Christian Orsted produces metallic aluminium in an impure form

- Augustin-Louis Cauchy presents the Cauchy integral theorem for general integration paths -- he assumes the function being integrated has a continuous derivative
- Augustin-Louis Cauchy introduces the theory of residues in complex analysis
- Johann Peter Gustav Lejeune Dirichlet and Adrien-Marie Legendre prove Fermat's last theorem for
*n = 5* - André-Marie Ampère discovers Stokes' theorem

- Georges Cuvier proposes his catastrophe theory as the cause of extinctions of large groups of animals
- Etienne Geoffroy Saint-Hilaire identifies Cuvier's fossil `crocodile´ as a teleosaurus

- September 27th - The world's first modern railway, the Stockton and Darlington Railway, opens

- May 4 - Sir Thomas Henry Huxley, English biologist († 1895)

- October 6 - Bernard Germain Etienne de la Ville, Comte de Lacepede, naturalist (* 1756)