BOOK REVIEWS t,imes shorter than those normally required for the mixing of solutions. This means r e a d i m s which are more than half over in about one second. He discusses Row methods; relaxation techniques, in which a n equilihrinm is perturbed by a. t,emperature or pressure puke or by ultrasonir absorpt.ion; rapid initiation of reactions by flash lamps; photo ehemirrrl, Ruoreseenre and eleetro-chemical methods; and measurements of the lifetimes of rhenlical species, e.g, free radicals or hydrated ions, hy means of electron spin or nuclear magnetic resonance. The final chapter is devaled to a discussion of several topics, such as d i k s i a n controlled reaction rates, which xre of particular interest in ronnection wit.h fast reart,ians in solution. The hook is well produretl with clear type and helpful diagrams. I t is vemsrkably free of typographiral errors. .4n author index would have been n real help in making the numerous reierences more useful to the reader. Caldin does not go into the details or experimental techniques or mathematical derivations. Instead he tries t o uut,line enough of each topic to rnske the presentation plausible. He then gives numerical result whirh illustrate the prnrticsl sppliration of the partic:ular method. This means that the reader can get an overall view of several techniques and a survey of many results. Anyone who wants to do similar research himself must searrh for more thorough t,t.mtments. By choosing to discuss fast reavtions as a group Caldin makes a n a h i t r a r y rlnsifiration whirh brings togetlrer otherrise unrelated systems. This is nat a pnrtiaularly ftuitiul choice from a pedagogical point, of view. Its justification comes f m m the interest and enthuxiasm whirh chemists feel when they realize that tlresc terhniqucs can open up so many fidds for erplot.ation. One of the outstanding exmmples of this is the spectacular surress which Eigen and his rollengues have had in extending kinet,ie mensut.ements in water sr,lutim tn renrt,ions whirh have half times as short as 1 O P s e r . Far fewer ~.eilrlions now have rabes which are "irnmensurwl,ly fast." The ho