The development of an area of scientific research is a dynamic process
with its own kinetic equations and its own physical mech- anism. The
study of fast chemical interactions and transformations is such an area,
and while it is tempting to draw analogies or to speculate about the
simplest model system, the lack of ade- quately averaged observables is
an annoying obstacle to such an undertaking. Sciences suffering from
such conditions usually avoid quantitative models, be they primitive or
complex. Instead, they prove their point by "case histories". Chemical
relaxation kinetics started as an offspring of research in acoustics. In
some aqueous ionic solutions anomalous acoustic absorption had been
observed. A systematic study traced the cause of this absorption,
showing that the covered frequency range and the intensity of the
absorption were related in a predictable manner to the rate at which
ions can interact and form structures differing in volume from the non
interacting species. The step from this experimental observation and its
correct, non- trivial explanation to the discovery that all fast
chemical pro- cesses must reveal themselves quantitatively in the
relaxation rate of a perturbed equilibrium state, and that perturbation
para- meters other than sound waves can be used for its exploitation,
was made by MANFRED EIGEN in 1954. The foresightedness of K.F.