The concept of this book - an integrated and comprehensive cov­ erage of all aspects of Raman spectroscopy by a group of specialist- took form nearly three years ago. It made a giant stride toward realization when Dr. L. Woodward, whose outstanding work in this field had long been known to me, agreed to write an introductory chapter and made valuable suggestions concerning others who might be invited to contribute articles. However, many obstacles had to be overcome before this book finally became a reality. It is extremely difficult to prepare a multi author review of the state of knowledge in a rapidly growing field in such a way that all aspects are brought up to the same date. In our case, some workers who had originally agreed to contribute articles were forced to withdraw under the pressure of new commitments, and replacements had to be found. Others were unable to complete their contributions by the deadline date, so that the publication of the book had to be rescheduled. All this tended to work to the detriment of those authors who prepared their chapters as originally scheduled. An effort was made to give the authors most affected by this an opportunity to revise their papers, but of course an arbitrary cutoff date had to be set to avoid an endless spiral of revision and updating.