26 BACTERIOLOGY. 



culture, to cultivate them indefinitely, to reproduce the 

 conditions by inoculation of these pure cultures into 

 susceptible animals, aud, by continuous inoculation from 

 an infected to a healthy animal, to continue the disease 

 at will. By the methods that he employed he demon- 

 strated a series of separate and distinct diseases that can 

 be produced in mice and rabbits by the injection into 

 their tissues of putrid substances. The disease known 

 as septicaemia of mice ; also a disease characterized by 

 progressive abscess formation ; and pyaemia and septi- 

 ca3mia of rabbits, are among the affections produced by 

 him in this way. It was in the course of this work that 

 the Abbe system of substage condensing apparatus was 

 first used in bacteriology ; that the aniline dyes suggested 

 by Weigert were brought into general use ; that the 

 isolation and cultivation of bacteria in pure culture on 

 solid media was shown to be possible ; and that animals 

 were employed as a means of obtaining from mixtures 

 pure cultures of pathogenic bacteria. 



With the bounteous harvest of original and important 

 suggestions that was reaped from Koch's classical series 

 of investigations bacteriology reached an epoch in its 

 development, and at this period modern bacteriology 

 may justly be said to have had its birth. 



NOTE. I have presented only the most prominent 

 investigations that will serve to indicate the lines along 

 which the subject has developed. For a more detailed 

 account of the historical development of the work the 

 reader is referred to Loeffler's Vorlesungen uber die ges- 

 chichtliche Entwickelung der Lehre von den Bacterien, 

 upon which I have drawn largely in preparing the fore- 

 going sketch. 



