Preface 



Civilized man, long having abandoned his worship of fire and sun, is 

 scarcely further advanced than his ancestors, since the fundamental 

 relation between the sun, the green plant and himself is still shrouded in 

 mystery. Not until the time comes when he can reproduce this ap- 

 parently simple process of photosynthesis in his laboratory, independent 

 of the green plant, can Man claim to be free from the vestiges of his 

 ancestral worship of sun and fire. When that day comes the energy 

 awaiting his disposal is enormous. 



Tang Pei-Sung 

 {Green Thraldom. Allen & Unwin Ltd., London 1949) 



In studying photosynthesis we have to distinguish between two main 

 problems: energetics and chemistry. Broadly speaking, the chemical part 

 of the process begins when the energetical part is completed. After light has 

 exerted its photochemical action, chemical reactions set in which enable the 

 plant to synthesize organic substance. A critical and objective review of the 

 work done on the photochemical energetic part of photosynthesis would sug- 

 gest that the work has been completed by Warburg and Burk. By contrast, 

 the study of the chemistry of photosynthesis is still in its infancy, in spite of 

 the many important investigations. that have been carried out. 



It is self-evident that in a book of this size it is not possible to refer to all the 

 work done in the field. In making a selection I have given preference to 

 those investigations which may be considered to-day to be classical and those 

 which seem to make new contributions to the understanding of Nature's 

 most important achievement. The descriptions of basic experiments are, in 

 most instances, illustrated by numerical examples. 



I gratefully acknowledge the kindness of the editors and publishers of 

 Angewandte Chemie, Federation Proceedings, Journal of General Physi- 

 ology, Naturwissenschaften, Science and Zeitschrift fiir Naturforschung in 

 granting permission for the reproduction of various diagrams which appeared 

 in their publications. My sincere thanks are due to Mr. N. K. Tregilgas for 

 his valuable help in preparing the English manuscript. 



W. Bladergroen 



Basle- Binningen 



Vll 



