Bacterial Metabolism, Normal and 

 Abnormal, Within the Body 



ARTHUR ISAAC KENDALL 



A. Introduction: The Significance of 

 Bacterial Metabolism 



That remarkable chapter in the history of the development of the 

 Science of Medicine which treats of the relations of microorganisms to 

 the causation of specific disease in man has exposed an entirely new and 

 extraordinarily fertile field for study and for speculation. 



The first two decades of this era were greatly enriched by the isolation 

 and identification of microbes which were shown to be etiological agents 

 in some of the most formidable infections of mankind. The second decade 

 of this period also witnessed the beginnings of specific bacterial therapy. 

 The brilliant investigations of Von Behring, Kitasato, Roux, Yersin, 

 Smith and others, upon the soluble toxins of diphtheria and tetanus 

 bacilli, and the preparation of their specific antitoxins, seemed to prepare 

 the way for a universal antitoxic therapy which should be efficacious in all 

 disorders of microbic causation. 1 



Time has shown, however, that antitoxic therapy is limited to a very 

 few specific . diseases. The development of the field of Immunology by 

 Ehrlich, Metchnikoff, Bordet and their followers, and the elucidation of 

 the nature of the complex reciprocal relationships between host and para- 

 site, which comprise the phenomena of infection and of resistance to infec- 

 tion have shown the basis for antitoxic therapy very clearly, and the 

 limitations which surround it. These studies also indicate very definitely 

 that entirely new procedures must be established to combat those micro- 

 organisms for whose pernicious activities no antitoxins can be prepared. 



The third decade of medical bacteriology has been endowed with 

 greatly improved methods of culture. These have led to the discovery of 

 many incitants of infection that had eluded the earlier attempts at isola- 

 tion. The rapid development of the Science of Serology, and the defini- 



1 Von Behring: Die Blutserum-therapie, Leipzig, 1892. 



663 



