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."

Agriculture seems to be a difficult sector to manage for most governments. Developing countries face tough dilemmas in deciding on appropriate price poli eies to stimulate food production and maintain stable, preferably low, prices for poor consumers. Governments in developed countries face similar difficult deci sions. They are called upon to give income guarantees to farmers whose incomes are unstable and relatively low when compared to those in the nonagricultural sector. These guarantees often lead to ever-increasing budgetary outlays and unwanted agricultural surpluses. High prices make new investments and the application of new technologies more attractive than world prices warrant, and a process is set in motion where technological innovation attains amomenturn of its own, in turn requiring price policies that maintain their rates of return. Surpluses are disposed of with subsidies in domestic markets or in the international market. Price competition reduces the market share of other exporters, who may be efficient producers, unless they are willing to engage in subsidy competition. This lowers export earnings and farm incomes or depletes the public resources of developing countries that export competing products. Retaliatory measures have led to frictions and further distortions of world prices. Every so orten the major agricultural exporters - the USA, the EC, Aus tralia, or Canada - accuse one another of unfair intervention. Though they have agreed to discuss agricultural trade liberalization under GATT negotiations, if anything, the expenditure on farm support has continued to increase in both the EC and the USA."

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.

Wie konnte es eigentlich zu der faszinierenden Fassade des Palazzo Rucellai kommen? Wer hat sie entworfen? In einer investigativen Recherche versucht der Autor diesen Fall endlich zu loesen. Wie ein Detektiv taucht er in das Florenz der Renaissance ein: Er untersucht das soziale Umfeld, und die Motive des Bauherrn, rekonstruiert das Geschehen und deckt schliesslich die Identitat des Taters auf: des Architekten dieser einzigartigen Palastfassade.