Editing 1801 in science (section)

==Physics==
* [[Dalton's law]]: [[John Dalton]] observes that the total [[pressure]] exerted by a [[gas]]eous mixture is equal to the sum of the [[partial pressure]]s of each individual component in a gas mixture.
* [[Ultraviolet]] radiation is discovered by [[Johann Wilhelm Ritter]].<ref>{{cite book|first=Armin|last=Hermann|year=1987|chapter=Unity and metamorphosis of forces (1800–1850): Schelling, Oersted and Faraday|title=Symmetries in Physics (1600–1980) |editor1-last=Doncel|editor1-first=M. G. |editor2-last=Hermann |editor2-first=A. |editor3-last=Michel |editor3-first=L. |editor4-last=Pais |editor4-first=A. |publisher=Universitat Autònoma de Barcelona|pages=51–62}}</ref><ref>{{cite journal|first1=Jan|last1=Frercksa|last2=Weberb |first2=Heiko |last3=Wiesenfeldt |first3=Gerhard |year=2009 |title=Reception and discovery: the nature of Johann Wilhelm Ritter's invisible rays |journal=Studies in History and Philosophy of Science Part A |volume=40|number=2|pages=143–156}}</ref>
* In optics, interference between light beams is discovered by [[Thomas Young (scientist)|Thomas Young]], showing the [[light wave|wave]] nature of light.