RELATIONS TO TISSUES. 3 



members read the current literature, they quote experiments, excel- 

 lently planned and carefully carried out by the originator, to prove 

 theories which in the mind of the originator never came to birth. 

 They use the bacillus indiscriminately, they make it the " be all and 

 end all " of disease. If a bacillus or a micrococcus is found, they 

 search no further, they are fully convinced, and all pathological 

 processes may be included in this single word " micro-organism." It is 

 not by such work and such reasoning that the position now attained 

 has been won ; no brilliant flash of genius alone has cast the present 

 flood of light upon the relations of germs to disease. Patient 

 observation, carried on by a few ardent and enthusiastic workers, 

 and the gradual and tedious accumulation of facts, combined with 

 careful and sound deductions, alone could place the " germ theory 

 of disease " upon its present solid and logical basis. Solid and logical 

 as this basis is, it must still be amplified in many directions. The 

 work carried on, up to the present by the few, must now be taken up 

 by the whole medical profession, or by as many as are anxious to deter- 

 mine the true position of the question. The amount of material at 

 command is enormous ; the methods have gradually been so simplified 

 that the busiest practitioner may help in the work, and by so doing 

 disabuse his mind of many exaggerated notions as to what is actually 

 proved and held by our modern authorities as to the relations 

 between micro-organisms and disease — in the first place generally, and 

 secondly in certain specific diseases. 



Relations of Micro-Organisms to the Tissues. 



3. It cannot be too strongly insisted upon at the outset that the pre- 

 sence of a micro-organism in the body, or in one of the cavities of the 

 body, may have not the slightest significance from an etiological point 

 of view. We are covered with them, the respiratory and alimentary 

 tracts are loaded with them, and it is not wonderful, therefore, that 

 we should be able to detect their presence on these surfaces. If this 

 fact is borne in mind, and when the numerous means of entrance 

 byway of the free surfaces, cutaneous, intestinal, &c., are considered, 

 one is inclined to marvel that they are not normally present in 

 enormous numbers in the deeper tissues, and that they are present only 



