10 PREFACE TO SECOND EDITION 



To have mentioned every worthy contribution to vitamin research 

 in the text would have made this volume so large and expensive as to 

 have limited its usefulness. In accordance with the policy adopted by 

 the Editors for this series of monographs, we have sought conciseness 

 for the sake of the reader rather than completeness of citation of the 

 work of every author who has contributed to the rapidly growing 

 literature of the vitamins. 



Recognizing that knowledge of vitamins touches closely the intel- 

 lectual and professional interests of many other scientifically trained 

 persons as well as professional chemists, we have sought to treat the 

 subject with the interests of all probable readers in view, and have thus 

 included more of physiological, pathological, nutritional and health 

 aspects than would otherwise be expected in a chemical monograph. 



The authors are greatly indebted to Dr. M. L. Caldwell, Dr. F. L. 

 MacLeod and Dr. H. K. Stiebeling for collaboration in the present 

 revision. 



