12 PREFACE TO SECOND EDITION 



In particular, however, we take pleasure in recording our apprecia- 

 tion of the assistance extended by the Hon. Herman A. Metz (New 

 York) who, although a layman in this field of work, understood its 

 significance and gave us the opportunity, after an enforced interrup- 

 tion of many years, of resuming the experimental work in the 

 "Research Laboratory of H. A. Metz." 



This book will be of interest not only to nutrition investigators 

 and childrens' specialists, but to every physician who comes into 

 touch with questions of the physiology of nutrition. It treats many 

 problems which are closely allied to other lines of research and will 

 be of value to plant physiologists, bacteriologists and animal breeders. 



CASIMIR FUNK. 



College of Physicians and Surgeons, 



Columbia University, 



New York City. 



December, 1921. 



