1 8 ESSENTIALS OF BACTERIOLOGY 



1863 that any positive advance was made in connecting bac- 

 teria with disease. Rayer and Davaine had, in 1850, found 

 a rod-shaped bacterium in the blood of animals suffering 

 from splenic fever (sang de rate), but they attached no special 

 significance to their discovery until Pasteur made public his 

 grand researches in regard to fermentation and the role 

 bacteria played in the economy. Then Davaine resumed his 

 studies, and in 1863 established by experiments the bacterial 

 nature of splenic fever or anthrax. 



But the first complete study of a contagious affection was 

 made by Pasteur in 1869, in the diseases affecting silk- worms, 

 pebrine and flacherie, which he showed to be due to 

 micro-organisms. 



Then Koch, in 1875, described more fully the anthrax 

 bacillus, gave a description of its spores and the properties 

 of the same, and was enabled to cultivate the germ on arti- 

 ficial media; and, to complete the chain of evidence, Pasteur 

 and his pupils supplied the last link by reproducing the same 

 disease in animals by artificial inoculation from pure cultures. 

 The study of the bacterial nature of anthrax has been the 

 basis of our knowledge of all contagious maladies, and most 

 advances have been made first with the bacterium- of that 

 disease. 



Up to 1875 most medical men believed that bacteria 

 originated in pus and did not associate them with the cause 

 of suppuration. Lister then began the practice of treating 

 wounds and operating antiseptically, having formed the 

 theory that inflammation and suppuration were due to the 

 contamination of wounds by germs from the air, instruments, 

 etc. From 1880 to 1890 the most important organisms were 

 discovered and associated with disease. 



In 1890 the discovery of the blood-serum therapy, the 

 antitoxin of Behring, established a new field of research, and 

 much work was undertaken with a view to curing disease. 



The researches of Ehrlich and the endeavors of Metch- 

 nikoff, Hankin and Ehrlich, to account for the phenomena of 

 immunity, brought forth a great mass of literature and es- 



