PREFACE vii 



crepancies will have to be accounted for, and many additions 

 made. It was, however, thought advisable to publish the book 

 for the reason that the experimental facts are accumulating so 

 rapidly that it is difficult for anyone to gather the leading ideas 

 unless they are presented more systematically and with less 

 detail than in the original publications. It was also thought 

 advisable to avoid in this volume a discussion of the possible 

 applications of the new theory to physiological and technical 

 problems. 



The writer wishes to express his appreciation to his technical 

 assistants, Mr. M. Kunitz, and Mr. N. Wuest, for the skill and 

 careshown in the measurementsre quired for the experimental 

 part of the work. 



The writer's thanks are also due to Dr. John H. Northrop, 

 Dr. D. I. Hitchcock, and Dr. Anne Leonard Loeb, who have read 

 part or all of the manuscript and offered valuable suggestions; 

 and to Dr. J. A. Wilson, who kindly read and revised the first 

 part of the chapter on swelling and suggested to the writer the 

 mathematical proof on page 143 of the book. 



The writer is indebted to Miss N. Kobelt for the reading of 

 the proof and for the index. 



JACQUES LOEB. 

 THE ROCKEFELLER INSTITUTE FOR 



MEDICAL RESEARCH, 



66rn STREET AND AVENUE A ; 



NEW YORK, N. Y. 



March, 1922 



