Essays on Bacteriology 



I. 



THE GERM THEORY OF DISEASE. 



THE germ theory^of disease, now no longer a the- 

 ory, but a demonstration of science, is a very sim- 

 ple doctrine. It asserts that certain disorders are due 

 to the presence and growth, in the body, of living 

 poisons called microbes, germs, bacteria, and that 

 without such bacteria these diseases do not exist. 

 IsTotice that certain disorders are said to have this 

 origin; for no one asserts or supposes that all diseases 

 are caused by bacteria. It is the maladies belonging 

 to the group called infectious which are due to living 

 agents, chief among which are the microscopic fungi 

 now commonly known as bacteria or germs. This 

 statement is a sufficient answer to the question, often 

 asked, whether we believe all diseases to be due to 

 microbes. 



And here we notice two interesting and important 

 facts growing out of bacteriology. The first is that 

 the revelations of bacteriology have altered the classi- 

 fication of diseases, increasing the number of those 

 included among the infections. Thus, the discovery 

 of the germ of diphtheria has resulted in establishing 



