Wilhelm Ostwald

Wilhelm Ostwald was born in 1853 in Riga, then part of the Russian Empire, to a Baltic-German family. He studied at the University of Dorpat (Tartu), and after professorships in Riga moved to Leipzig in 1887, where he built one of the world's foremost schools of physical chemistry. Through his textbooks, his journal 'Zeitschrift für physikalische Chemie,' and a stream of distinguished students, he did more than almost anyone to establish physical chemistry as a discipline in its own right.

Ostwald's scientific contributions were broad: the dilution law for weak electrolytes that bears his name, foundational work on catalysis and reaction rates, and the Ostwald process for the industrial oxidation of ammonia to nitric acid, still in use today. He received the Nobel Prize in Chemistry in 1909, principally for his work on catalysis and chemical equilibria.

Philosophically, Ostwald was the leading advocate of 'energetics,' a programme that sought to base physical science on energy and its transformations alone, treating atoms and molecules as unnecessary or even meaningless hypotheses. This put him in sustained opposition to Boltzmann's atomistic statistical mechanics; the two clashed repeatedly, most famously at the 1895 Lübeck meeting of German scientists. Ostwald held that thermodynamics, dealing only in measurable energies, was sounder than any picture built on invisible particles.

He conceded the existence of atoms only after the experimental evidence became overwhelming — Einstein's 1905 theory of Brownian motion and Jean Perrin's confirming measurements — acknowledging in 1909 that the atomic hypothesis had been established. In later life Ostwald turned to colour theory, the philosophy and organisation of science, and internationalist causes.