Arrhenius, ahr RAY nih us, Svante August (1859-1927), was a Swedish chemist and physicist. His theory of electrolytic dissociation (or ionization) in the conductivity of solutions developed the original work of Sir Humphry Davy and Michael Faraday. It won for him the 1903 Nobel Prize for chemistry. Arrhenius first presented the theory as his doctoral thesis at Uppsala University in 1884. All the leading scientists of the world gradually accepted it.