20 INTRODUCTION . 



shown to be the etiological factor of a bacterial disease. Koch also 

 found that the anthrax bacillus formed spores. 



From this time bacteriology developed with amazing rapidity. In 

 1882 Koch startled the world with the announcement of the dis- 

 covery of the tubercle bacillus; and in rapid succession, typhoid, 

 diphtheria, cholera, tetanus and other well-known pathogenic bacteria 

 were isolated and studied in pure culture. 



In 1882 Metchnikoff published the first of his highly important 

 contributions to immunity and phagocytosis, and a decade later von 

 Behring and Kitasato announced the discovery of diphtheria antitoxin. 



The last three decades have not only witnessed the rise and develop- 

 ment of those most brilliant chapters of medicine, infection and im- 

 munity; but sanitation, agriculture, many industries and other fields 

 of human activity have benefited largely by the development of 

 bacteriology. 



In medicine the diagnosis of bacterial disease has reached a high 

 degree of precision, and bacteriological diagnosis is an important 

 branch of medical science. The most important problem for the future 

 is to create a system of Bacterial Therapeutics of equal efficiency. 



