The present title "Biology of Physical Science" is an attempt to provide an uptodate account of the physical processes used in biological sciences. It is basically designed for students, research scholars, teachers, biochemists, microbiologists, immunologists and pharmaco-Iogists at various universities, institutions and laboratories. This book will enable the user to find his way through the large and often bewildering array of methods currently available. Each chapter has been written in the light of modern development in a simple and lucid style. Sincere efforts have been made to inClude those topics which have been found to be common among the various university syllabi.