PREFACE TO THE FIRST EDITION ix 



ena are changing so rapidly, no pretense has been made of examining 

 completely the practical applications of this important subject. 



Due to the fact that more detailed studies have been made on the 

 production, nature, and utilization of penicillin, more information is 

 presented about this than about any of the other substances. However, 

 this should not be construed as desire on the author's part to emphasize 

 this substance. 



The subject of antagonistic effects of microorganisms has been re- 

 viewed in both general treatises (706, 944) and special papers (268, 

 440, 443, 449, 580, 621, 730, 836, 867, 986) J special attention has been 

 paid to the occurrence of such organisms in the soil (316, 670, 941). 

 Advantage was taken of these reviews in the preparation of the com- 

 prehensive bibliography presented at the end of this monograph. At- 

 tention is directed also to a recent complete review of the literature on 

 the nature and formation of penicillin, the historical development of 

 our knowledge of this agent, method of assaying, and clinical applica- 

 tion (410). 



The author expresses his sincere appreciation to the members of the 

 staff of the Microbiology Department, New Jersey Agricultural Ex- 

 periment Station ; to members of the Department of Research and De- 

 velopment of Merck & Co. and of the Merck Institute for permission 

 to use reproductions of their work, especially the photograph of strep- 

 tomycin crystals J to members of the staff of E. R. Squibb & Sons for 

 supplying the photograph of the penicillin-sodium crystals used as the 

 frontispiece to this volume j to Mrs. Herminie B. Kitchen for her care- 

 ful editing of the manuscript j and to the many investigators in the field 

 whose work has been freely cited both in the form of text or tabular 

 matter and as illustrative material. 



S. A. W. 

 November i^, ig44 



