PREFACE TO THE THIRD EDITION 



The application of biochemical techniques to the study of 

 bacteria has thrown considerable light on the mode of existence 

 of these organisms and, in turn, such studies have assisted the 

 development of our knowledge of the fundamental biochemistry 

 of Hving cells. In this book I have attempted to produce an 

 account of the chemical activities of bacteria which will be 

 useful to students reading biochemistry, bacteriology, or 

 chemistry, and which will provide an introduction to more 

 advanced study. I hope also that the book will prove useful 

 to research w^orkers who require a concise but not detailed 

 account of the background to ^^resent research in chemical 

 microbiology. The treatment is elementary and in no sense 

 comprehensive, and the bibliography has been limited, for the 

 inost part, to review articles and textbooks. 



A comparatively new subject, such as this is, tends to 

 develop rapidly and, although experimental facts must remain 

 true, the accumulation of new facts inevitably alters the 

 approach towards certain aspects of the subject. For examj)le, 

 during the last three or four years considerable advances have 

 been made in our knowledge of synthetic systems and their 

 control in the bacterial cell by "genes". I have attempted to 

 incorporate some of these new ideas, and the facts on which 

 they are based, in this third edition. In the course of making 

 the changes I have found it desirable to alter the order of 

 presentation of some of the material and to condense some 

 sections in order that the book shall remain of a23proximately 

 the same size. 



I wish again to express my indebtedness to the late Dr 

 Marjory Stephenson, F.R.S., for awakening and encouraging 

 my interest in bacterial chemistry. I wish also to thank all 

 those of my colleagues who have helped me to correct and 

 avoid errors during the preparation of this book. 



E. F. G. 



Medical Research Council Unit 

 for Chemical Microbiology, 

 Biochemistry Laboratory, 

 Cambridge. 

 1951 



