Synopsis It is a matter of great pleasure to present the Book entitled, "Photochemistry" for meeting the longfelt requirements of B.Sc., B.Sc. (Hons.), M.Sc. and Engineering students of all Indian Universities. Photochemistry is not only responsible for our existence in the universe but also finds a wide variety of applications in various areas such as chemical, textile, electronic, electrical, photography, printing, metallurgical, medical and geological applications. Photochemistry is fast developing branch of physical chemistry. There are few books of this kind are available for students, teachers, biochemists, microbiologist and other allied scientific disciplines. Thus this book has been planned in that spirit. Apparently obscure phenomena are explained in an informal, simple, lucid and readable style. The book has been written to cover the syllabi of different universities.