PREFACE 

 to Volume II, Part 1 



The manuscript of ^'oUlme II of this monograph was ready in draft 

 foi-m when the first vokime was dehvered for pubHcation in 1944. After 

 the intermption caused by war, I felt reluctant to publish the second 

 volume without thorough revision in the light of new research data and 

 of my own better understanding of some of the phenomena discussed. 

 I began, in 1947, a revision of the manuscript; while I was revising the 

 material, research in the field of photos^Tithesis picked up after the war- 

 time slack, and the writing became something of an Achilles vs. turtle race. 

 When, finally, the text achieved a temporary completeness, the count of 

 the galleys revealed that it had become too long to be published under 

 one cover. It was therefore divided into two half-volumes. The division 

 cut through the part dealing with the kinetics of photosynthesis. Because 

 of this, it seemed inadvisable to provide this half-volume with a separate 

 subject index; an index for the whole work will be found at the end of the 

 second part.* The latter will complete the treatment of the kinetics of 

 photosjmthesis (temperature effects, flashing light experiments, induction 

 phenomena, and the function of the pigments, especially the energy transfer 

 between them). The last three chapters will constitute an addition to 

 Volume I, and will deal particularly with the new work on photochemistry 

 of pigments (in solution and in chloroplasts) , and with studies of the 

 chemistry of carbon dioxide reduction by means of radioactive carbon. 



The hopeful advance in these two fields has changed the appearance 

 of the whole field of photosjTithesis. The analysis of kinetic data, to 

 which many pages in this half -volume are devoted, now seems somewhat 

 like an attempt to reach a treasure chamber by drilling through steel walls 

 while keys have been found to unlock the door. However, photosjTithesis 

 is not only a biochemical process in which all we want to learn is the 

 chemical composition of the intennediates and the nature of the enzymes 

 involved. It is also a most interesting physicochemical phenomenon; 

 its kinetics will be worth continued study even after organic chemists 



* As in Volume I, an index of the most important investigations described is pro- 

 vided at the end of this half-volume. 



