PREFACE VU 



been attempted, although the very nature of this work often makes a 

 concise statement of the results difficult if not impossible. 



The original plan envisaged the division of the book into three parts: 

 the chemical mechanism of photosynthesis and chemosynthesis; the 

 properties of photosynthetic pigments; and the kinetics of photosyn- 

 thesis. Publication of the treatise in two volumes, made necessary partly 

 by its bulk and partly by exigencies of war work which caused an inter- 

 ruption of uncertain duration in the preparation of the manuscript, led 

 to a subdivision of the second part. The work is thus now divided into 

 four parts: I, The Chemistry of Photosynthesis and Related Processes; 

 II, The Structure and Chemistry' of the Photosynthetic Apparatus; III, 

 The Spectroscop3' and Fluorescence of the Pigments; and IV, The Ki- 

 netics of Photosynthesis. The first two parts form the present Volume I, 

 which contains predominantly chemical matter. Parts III and IV will 

 be included in the second, predominantly physical, volume. Most of 

 the second volume is now ready in draft form, and it is hoped that its 

 publication will be possible within a year. Thanks are due to Inter- 

 science Publishers, Inc., for the patience with which they have borne 

 the expansion of the manuscript beyond its originally intended scope 

 and the delays ensuing from this growth. 



My interest in photosynthesis originated in the work on the photo- 

 chemical properties of chlorophyll, carried out in 1937-1938 at Uni- 

 versity College, in London. In the summer of 1938, during a stay at the 

 Marine Biological Laboratory at Woods Hole, with its unique library, 

 where practically every biological, chemical or physical periodical in the 

 world is available twenty-four hours a day, I first started collecting 

 material on photosynthesis and related subjects. My intention was to 

 see whether this heterogeneous material could be fitted into a unified 

 picture to serve as an incentive and guide for further experiments, but 

 the work soon expanded bej^ond this original aim. Most of the manu- 

 script was written at Woods Hole during that and three subsequent 

 summers. My work at the Solar Energy Research Project of the Massa- 

 chusetts Institute of Technology, while not concerned directly with 

 photosynthesis, helped to keep alive an interest in the subject, since, in 

 experimenting on the conversion of light energy into chemical energy, 

 one cannot but turn continuously to plants and wonder how Nature has 

 achieved a result which has not yet been approached in the laboratory. 

 This work could not have been completed without the understanding 

 help of the Solar Energ\^ Project Committee, which not only made 

 possible use of part of my time for the completion of the manuscript, 

 but also provided a grant toward the expenses of its technical preparation. 



