Stability is one of the most important performances required for silver halide photographic materials. In 1935, Dr. E. 1. Birr introduced the concept of the stabilization ofphotographic emulsions for the first time by inventing a most effective stabilizer, 4-oxo-6-methyl-l,3,3a,7-tetraazaindene (TAl). Dr. Birr's monograph Stabilization ofPhotographic Silver Halide Emulsions was published in 1974,and accepted as a reliable reference book by many photographic scientists and engineers. Since then, silver halide photographic materials have been greatly improved and expanded through active and continual development of various kinds of technologies. Especially, extensive efforts have been made to develop photographic materials with high sensitivity and rapid processing, which rely upon the stability ofphotographic emulsions under various conditions. Thus, the concept and technologies of stabilization ofphotographic silver halide materials have been expanded so extensively that many photographic scientists and engineers eagerly want a reliable, new reference book on the stabilization of photographic emulsions. Dr. Gunther Fischer is one of the most experienced and eminent scientists and engineers in the field of the stabilization of photographic materials with expanded concept. He has been involved in research on the stabilization of pho­ tographic emulsions since 1964 when he joined the Technical Scientific Laboratory in the Research and Development Department of the Photo Film Company Agfa Wolfen formerly headed by Dr. Birr, whom he succeeded in that position. I was deeply impressed by his fruitful and elaborate achievements in these fields.