64 



\/\th March, 1899. 



Mr. Thomas Workman, J. P., President, in the Chaw. 



PATHOGENIC BACTERIA WITH SPECIAL 

 REFERENCE TO THE TYPHOID BACILLUS. 



By J. LoRRAiN Smith, M.A., M.D. 

 {Abstract.) 



The natural processes for which bacteria are responsible are 

 very numerous, but a rough classification of these may be made 

 by dividing them into three groups — viz., fermentation, putre- 

 faction, and the production of disease. 



In regard to fermentation, suggestive conclusions were 

 established in the first instance, showing that the ferment 

 producer is a living organism which has in suitable conditions 

 the power of indefinite self-multiplication, and that in unsuit- 

 able conditions it dies out and cannot be revived except by the 

 introduction anew of living organisms of the same kind. 

 Subsequent study revealed many characters whereb}' the 

 different organisms could be recognised, and also the condi- 

 tions, which were most favourable to their activity. The same 

 methods of study applied to disease have shown that many acute 

 infectious fevers and allied conditions are due to microbes, and 

 it is to this branch of the science of bacteriology that I wish now 

 to refer. 



A short introduction in regard to general principles will be 

 of service. 



We have, in the first place, to devise means for giving to the 

 microbes we wish to cultivate the most suitable conditions for 

 their growth, and for this purpose various ingenious methods 

 have been adopted. The food which the microbe requires is 



