Vlll PREFACE 



nor with the cheiiiistiy of cultiiic Jiiedia and staining 

 reactions. Their treatment here could be little more than 

 a catalogue of substances and organisms, for although a 

 large body of empirical data concerning them is available, 

 we have as yet but little exact chemical knowledge of the 

 mechanisms involved. 



In the hope that the interest of students reading the 

 following j)ages will have been stimulated, sources of 

 further information have been indicated at the ends of 

 the chapters. 



Acknowledgment is gratefully made to the authors of 

 the many monographs, standard works and papers which 

 have been drawn upon freely for the material collected 

 here. 



It is a pleasure to record my deep indebtedness to 

 Professor H. Raistrick, F.R.S., of the London School of 

 Hygiene and Tropical Medicine, who awakened my 

 interest in this subject, and to Professor T. J. Mackie, to 

 whose keenness and encouragement the course in this 

 University owes its inception. 



C. G. ANDERSON. 



Defabtmexnt op Bacieriology, 



University of Edinburgh, 



December, 1937. 



