GIBBS, JOSIAH WILLARD American mathematical physicist, was born at New Haven, Conn., on Feb. 1839. Entering Yale in 1854 he graduated 1858, and in 1863 went to Europe, studying in Paris in 1866-67, in Berlin in 1867 and in Heidelberg in 1868. Returning to New Haven in 1869, he was appointed professor of mathematical physics at Yale in 1871 and held that position till his death on April 28, 1903. His first contributions to mathematical physics were two papers published in 1873 on "Graphical Methods in the Thermodynamics of Fluids," and "Method of Geometrical Representation of the Thermodynamic Properties of Substances by means of Surfaces." His next and most important publication was his famous paper "On the Equilibrium of Heterogeneous Substances" (1876-78), which, it has been said, founded a new department of chemical science. This was translated into German by W. Ostwald (who styled its author the "founder of chemical energetics") in 1891 and into French by H. le Chatelier in 1899. In 1881 and 1884 he printed some notes on the elements of vector analysis for the use of his students; these were never formally published, but they formed the basis of a text-book on Vector Analysis which was published by his pupil, E. B. Wilson, in 1901. Between 1882 and 1889 a series of papers on certain points in the electromag netic theory of light and its relation to the various elastic solid theories appeared in the American Journal of Science, and his last work, Elementary Principles in Statistical Mechanics, was issued in 1902. The name of Willard Gibbs, who was the most distinguished American mathematical physicist of his day, is especially associated with the "Phase Rule." In 1901 the Copley medal of the Royal Society of London was awarded him as being "the first to apply the second law of thermodynamics to the ex haustive discussion of the relation between chemical, electrical and thermal energy and capacity for external work." For biographical sketch see his Scientific Papers (1906) .
See W. L. Miller, The Method of Willard Gibbs in Thermodynamics (1925) ; E. Cohen, "Semi-Century of Willard Gibbs's Phase Law, 1876-1926," in Science, n.s. vol. lxiv., p. 621 (1926) ; and John Johnson "Josiah Gibbs: An Appreciation," in Scientific Monthly, Feb., 1928, pp. 129-139.