This section is from the book "The Fundamentals of Photography", by C. E. K. Mees,. Also available from Amazon: The Fundamentals Of Photography.
While a knowledge of the theory of photography is by no means essential for success in the making of pictures, most photographers must have felt a curiosity as to the scientific foundations of the art and have wished to know more of the materials which they use, and of the reactions which those materials undergo when exposed to light and when treated with the chemical baths by which the finished result is obtained. This book has been written with the object of providing an elementary account of the theoretical foundations of photography, in language which can be followed by readers without any specialized scientific training. It is hoped that it will interest photographers in the scientific side of their work and aid them in getting, through attention to the technical manipulation of their materials, the best results which can be obtained.
Rochester, N. Y. January, 1921