BOOK REVIEWS for a wide variety nf isotopes t,hat i t probably will short,ly out.numher all of the other counting techniques and might have reccived more than just a casual mention. The advantages of this method are numerous, but the sources of difficulty are apparently lsrgrly unknonm t o many who sttempt t o use thr technique. The treatment of nrutron activnt,ion docs not mention the possihi1it.v nf producing (n, Zn), (n, p ) and (n, a ) reactions with f a t neutrons which sre n l ~ n y spresent in any neutron sonrre. \Vhile the clTeet,ive fast nuutnm flux may I,r much smaller than the thermal flux, t,he possibility of producing carrier free aet,ivities hy t,he (n, D) and (n, . . a). reactions is oeensionallv useful. The book is well hound and modestly priced and should find wid
