Willard Gibbs,*in full Josiah Willard Gibbs* *(born February 11, 1839,*New Haven, Connecticut, U.S.—died April 28, 1903,*New Haven),*theoretical physicist and chemist who was one of the greatest scientists in the United States in the 19th century. His application of thermodynamic theory converted a large part of physical chemistry from an empirical into a deductive science.

Gibbs was the fourth child and only son of Josiah Willard Gibbs, Sr., professor of sacred literature at Yale University. There were college presidents among his ancestors and scientific ability in his mother’s family. Facially and mentally, Gibbs resembled his mother. He was a friendly youth but was also withdrawn and intellectually absorbed. This circumstance and his delicate health kept him from participating much in student and social life. He was educated at the local Hopkins Grammar School and in 1854 entered Yale, where he won a succession of prizes. After graduating, Gibbs pursued research in engineering. His thesis on the design of gearing was distinguished by the logical rigour with which he employed geometrical methods of analysis. In 1863 Gibbs received the first doctorate of engineering to be conferred in the United States. He was appointed a tutor at Yale in the same year. He devoted some attention to engineering invention.

Gibbs lost his parents rather early, and he and his two older sisters inherited the family home and a modest fortune. In 1866 they went to Europe, remaining there nearly three years while Gibbs attended the lectures of European masters of mathematics and physics, whose intellectual technique he assimilated. He returned more a European than an American scientist in spirit—one of the reasons why general recognition in his native country came so slowly. He applied his increasing command of theory to the improvement of James Watt’s steam-engine governor. In analyzing its equilibrium, he began to develop the method by which the equilibriums of chemical processes could be calculated

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Gibbs was the only son among the five children of Josiah Willard Gibbs and Mary Anna Van Cleve Gibbs. His father was a noted philologist, a graduate of Yale and professor of sacred literature there from 1826 until his death in 1861. The younger Gibbs grew up in New Haven and graduated from Yale College in 1858, having won a number of prizes in both Latin and mathematics. He continued at Yale as a student of engineering in the new graduate school, and in 1863 he received one of the first Ph.D. degrees granted in the United States. After serving as a tutor in Yale College for three years, giving elementary instruction in Latin and natural philosophy, Gibbs left New Haven for further study in Europe. By this time both his parents and two of his sisters were dead, and Gibbs traveled with his two surviving older sisters, Anna and Julia. He spent a year each at the universities of Paris, Berlin, and Heidelberg, attending lectures in mathematics and physics and reading widely in both fields. These European studies, rather than his earlier engineering education, provided the foundation for his subsequent career.

Gibbes returned to New Haven in June 1869. He never again left America and rarely left even New Haven except for his annual summer holidays in northern New England and a very occasional journey to lecture or attend a meeting. Gibbs never married and lived all his life in the house in which he had grown up, less than a block away from the college buildings, sharing it with Anna, Julia, and Julia’s family. In July 1871, two years before he published his first scientific paper, Gibbs was appointed professor of mathematical physics at Yale. He held this position without salary for the first nine years, living on his inherited income. It was during this time that he wrote the memoirs on thermodynamics that constitute his greatest contribution to science. Gibbs had no problem about declining a paid appointment at Bowdoin College in 1873, but he was seriously tempted to leave Yale in 1880, when he was invited to join the faculty of the new Johns Hopkins University at Baltimore. Only then did Yale provide a salary for Gibbs, as tangible evidence of the esteem in which he was held by his colleagues and of his importance to the university, but this salary was still only two thirds of what Johns Hopkins had offered him. Gibbs stayed on at Yale nevertheless and continued teaching there until his death, after a brief illness, in the spring of 1903