Gibbs, Josiah Willard (1839–1903)
Josiah Gibbs was a US theoretical physicist and chemist best known for his pioneering work
in chemical thermodynamics. While
a professor at Yale, he devoted himself to establishing the basics of physical
chemistry. In On the Equilibrium of Heterogeneous Substances (2
vols, 1876 and 1878) he stated Gibbs' phase rule (see phase
equilibria). The quantity known as Gibbs free energy is named after him. Gibbs also made fundamental contributions
to the subject of vector analysis.