1805 in science

The year 1805 in science and technology involved some significant events, listed below.

Events

* John Dalton's "Absorption of Gases", the first list of molecular weights is published.

Exploration

* April 7 - The Lewis and Clark Expedition leaves Fort Mandan, bound for the Pacific Ocean.
* August 9 - Zebulon Pike leaves St. Louis to explore the headwaters of the Mississippi River.
* November 16 - The Lewis and Clark expedition reaches the Pacific Ocean at the mouth of the Columbia River.

Awards

* Copley Medal: Humphry Davy

Births

* February 13 - Peter Gustav Lejeune Dirichlet, mathematician (died 1859)
* May 12 - William Rowan Hamilton, mathematician, physicist, and astronomer (died 1865)
* December 16 - Isidore Geoffroy Saint-Hilaire, zoologist (died 1861)
* December 20 - Thomas Graham, chemist (died 1869)

Deaths

* January 23 - Claude Chappe, inventor of the semaphore system (born 1763)
* December 23 - Pehr Osbeck, Swedish botanist and explorer, pupil of Linnaeus (born 1723)