PREFACE TO THE SECOND EDITION 



WHEN iheliryt edition of tJi is hook appeared in 11)38 

 it was considered that the suhject of Chemotherapy 

 of bacterial infections was in too primitive a state 

 to warrant inclusion. The advance in our knowledge 

 since then has made it possible and desirable to consider 

 the topic in some detail. The ideas on which the 

 explanation of chemotherapeutic action is based, and 

 which form the foundation for plamiing further investiga- 

 tion, involve the chemistry of metabolic processes and 

 naturally come within the scope of this book. Similar 

 considerations lead to the inclusion of a chapter on 

 Antibiotics and to a fresh presentation of the facts known 

 about Gro\\i;h Factors. These chapters constitute the 

 main difference between the first and the present editions, 

 but new material has been added to a number of other 

 chapters in order to keep level, as far as possible, with 

 the changes involved in such a rapidly growing branch of 

 Biochemistry. 



Some criticism has been expressed that bibhographical 

 references to the original literature were not given in the 

 first edition. It is the opinion of the author that a 

 detailed bibliography is out of place in a small textbook 

 intended primarily for students, but in order to extend 

 the usefulness of the volume an endeavour has been 

 made to give, at the end of each chapter, some references, 

 mainly to monographs and reviews, which will serve as 

 a guide to the original papers. 



Once more it is a pleasure to acknowledge my debt to 

 the authors whose works have supplied the material 

 presented. Especially are my thanks due to colleagues 

 and friends for much helpful criticism and advice. 



C. G. ANDERSON. 



Wellcome Physiological Research Laboratories 



Laxgley Court, Beckenham, Kent 



July, 1946 



