Physical Chemistry: Neither Fish nor Fowl?

The birth of a new discipline, called ‘physical chemistry’, is sometimes related to the names OSTWALD, ARRHENIUS and VAN’T HOFF and dated back to the year 1887, when OSTWALD founded the Zeitschrift für physikalische Chemie. But as many historians have pointed out, the phrase ‘physical chemistry’ was widely used before that and the topics under investigation partially go back to Robert BOYLE’s attempts to connect chemistry with concepts of mechanical philosophy. The idea of a sudden birth of physical chemistry in 1887 seems to be a founder myth. But there is no doubt that in the late nineteenth-century there was a rapid growth of research in fields now understood as physical chemistry: chemical thermodynamics, electrochemistry, photochemistry, spectroscopy, chemical kinetics etc. Historians (and sociologists) of science have proposed several categories to describe the genesis and to fix the identity of scientific ‘disciplines’, ‘fields’, ‘traditions’, ‘paradigms’, ‘research schools’ etc. In what follows, I will not consider sociological categories but concentrate on knowledge based philosophical or methodological aspects to describe characteristics of physical chemistry as a research field. Certainly, physical chemistry is in a sense related to physics as well as to chemistry establishing some relation between the two fields. But what kind of relation does it establish? Is it a kind of reductive relation reducing or integrating chemistry to some unifying physical science, as NERNST and even OSTWALD thought? Or should we treat physical chemistry as a link between physical methods and concepts and chemical topics? Or does it just fill a gap between chemistry and physics, which