PREFACE vii 



Dr. Cramer, of the Imperial Cancer Research Laboratory, for 

 criticism in the chemical portions of the book, and Dr. Leonard 

 Kidd for references to literature. To Mr. Samson Wright I 

 am deeply indebted for his services in the revision of the whole 

 book, and to Mr. J. W. Brown for assistance in the preparation 

 of the index. 



I owe a debt of gratitude to Sir Edward Sharpey Schafer for 

 his kindly encouragement and advice on various matters 

 extending over a period of many years. From the time when 

 I had the privilege of acting as his assistant in University 

 College, London, he has always been ready to place the services 

 of his laboratory at my disposal and to assist me in numerous 

 other ways. 



SWALE VINCENT. 

 MIDDLESEX HOSPITAL 

 MEDICAL SCHOOL, 

 February, 1922. 



