This book is for the most part made up of the invited papers presented at the International Conference on Applica tions of the Kdssbauer effect, held at Aye1eth Hashahar, Israel, in August 1972. The purpose of the conference was to review perspec tives in MHssbauer spectroscopy from the point of view of applications in various fields of science - mainly physics, chemistry, and biology. It was hoped that the bringing together of scientists who work in different disciplines but use a common tool would encourage interdisciplinary re search and widen the horizon of the individual researcher. Both these features have been an important and unique characteristic of Kdssbauer research in the past decade. Accordingly, the main papers were presented in the following areas: magnetic properties of solids, applications to in organic chemistry, biochemical studies, amorphous systems, metal alloys, advances in high-resolution studies, and the new techniques for studying recoil-free spectra from isolated atoms in inert materials. A special panel discussion was devoted to the subject of phase transitions. Recent years have witnessed a rapid growth in the use of X-ray photoelec tron spectroscopy for the study of the physics and chemistry of solids. A report on this area of research and its rela tion to Kdssbauer studies has been included.