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268 A · ANALYTICAL CHEMISTRY, VOL. 50, NO. 2, FEBRUARY 1978
appropriate solvent, is excited to some high vibrational level of the ground electronic state. Two different types of measurements are described. First, coherent probing is used to determine the length of time required for colli sions, energy transfer, etc., to dephase the excited vibrations. Second, inco herent R a m a n scattering is used to monitor the decrease in population of the same state. T h e work described should appeal to those analytical chemists interested in time-resolved spectroscopy or the use of coherent scattering techniques such as CARS. An overall balance was attained be tween theory, experiment, and results. In particular, there are several very useful discussions about potential ex perimental pitfalls. T h e examples were well chosen to both represent t h e two methods of excitation and to dis cuss the dephasing and depopulating data. T h e chapter ends on a positive note by presenting the results, ob tained for coumarin 6, which is com posed of ~ 5 0 atoms. R. D. Levine and A. Ben-Shaul have written a chapter on the thermody namics of molecular disequilibrium, with emphasis on applications rele vant to chemical lasers. T h e discus sion is divided into three sections. First, information theory is used to develop state functions useful for sys tems in molecular disequilibrium. Sec ond, these results are used to snythesize the energy state distribution of nascent, unrelaxed collision products. And finally, by use of a maximum en tropy approach it is shown how the time-dependent energy distribution of the products can be predicted. T h e work described should appeal to those analytical chemists interested in bond-specific infrared photochemis try. T h e chapter is very heavy on theory and will probably prove diffi cult going for the average reader. Sur prisingly, the reviewer found the first section on information theory the eas iest to comprehend because it as sumed a weaker prior knowledge than the last two parts. B. R. Ware is author of a fascinating chapter on the applications of laser velocimetry in biology and medicine. In this experiment the Doppler shift in the frequency of light scattered from a moving object is used to com pute its velocity. T h e work described should have a broad appeal while pro viding specific examples of interest to a bioanalytical chemist. In this chap ter, the basic experiment and opera tional principles are very briefly de scribed, while most of the coverage is reserved for length descriptions of se lected experiments. T h e discussion of
