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...