(b. Eudorf, near Alsfeld, Prussia, 31 July 1837; d. Giessen, Germany, 16 March 1922)
The son of a Protestant minister, Naumann attended the Gymnasium in Darmstadt and then studied chemistry and mathematics at the University of Giessen. After graduating in 1858 he became an assistant at the technical school in Darmstadt and in 1860–1861 was an assistant in the chemistry institute of the University of Tübingen. He moved to Giessen in 1862 and taught mathematics in the Gymnasium there. Naumann qualified as a lecturer in chemistry in 1864 at the University of Giessen. While continuing to teach at the Gymnasium, he lectured and conducted research at the university. He became associate professor in 1869 and, in 1882, full professor and director of the chemistry laboratory, where he remained active until his retirement in 1913.
Naumann began his scientific work in organic chemistry with an investigation of the chlorination of butyric acid and studies of the esters of benzoic acid. In his Habilitationsschrift, which dealt with the bromination of acetyl chloride, his interest in the study of the reaction mechanism was already evident. From this time on, he dedicated himself to physical chemistry, especially thermochemistry, During the 1860’s the thermodynamic knowledge recently ac- quired in physics was slowly penetrating the field of chemistry, and the results of Naumann’s tireless work contributed significantly to preparing the way for later important discoveries in chemical thermodynamics.
In an essay (1867) that can be considered a contribution toward Guldberg and Waage’s law of mass action, Naumann expressed the view that only those molecules which possess energy higher than the critical energy can react with each other. At a constant temperature molecules form and disintegrate, thus producing an equilibrium. With increasing temperature the number of molecular collisions increases while the reaction velocity increases at an ever greater rate.
In his investigation in 1878 of the dissociation process N2O4 ⇌ NO2 Naumann demonstrated the validity of the law of mass action, which had already been formulated. Many of his papers dealt with the equilibrium ratios between water vapor and various crystal hydrates, as well as determinations of vapor densities and heats of decomposition.
Naunmann’s scientific activity diminished drastically after his appointment as full professor at Giessen. Perhaps the legacy of his predecessors at the chemistry laboratory, Liebig and Heinrich Will, both great organic chemists, proved too heavy a burden. More- over, his responsibility for teaching primarily organic chemistry diverted him from the field in which he had originally done creative work—without providing a substitute. As a result he devoted himself to university administration and took an interest in politics.
Naumann’s most important books are Grundriss der Thermochemie (Brunswick, 1869); and Lehr- und Handbuch der Thermochemie
(Brunswick, 1882), Many of his other publications are listed in Poggendorff, III, 958–959; IV, 1059; V, 895. An obituary is Akademische Rede zur Jahres- feier der Hessischen Ludwigs Universität (Giessen, 1922),43.