1894.] 31ICE0SC0PICAL JOURNAL. 293 



The bearing of these facts upon the question of pro- 

 phylaxis seems almost too obvious to need special men- 

 tion , this portion of the subject might be here dismissed 

 but for the fact that many still entertain the idea that 

 the relation of the tubercle bacillus to tuberculosis is 

 a matter about which there exists much doubt, the claims 

 in the affirmative being believed by them to rest chiefly 

 upon the opinions of over-zealous or impractical bacterio- 

 logists ; and for the reason that certain authorities have 

 recently come forward with the statement that tubercle 

 bacilli bear no more -relation to tuberculosis than do cer- 

 tain other micro-organisms ; that we may and do have 

 tuberculosis, without the presence or intervention of the 

 tubercle bacilli ; and that in carrying out measures of 

 prophylaxis against tuberculosis disinfection may be 

 safely disregarded. 



The truth is that no question in general pathology rests 

 on a firmer foundation than does the fact that the tubercle 

 bacillus is' the essential cause of tuberculosis. Not only 

 are those bacilli constantly present in this disease, and 

 absent from non-tubercular lesions, but when isolated 

 in pure culture, even through several generations, and 

 then introduced into the bodies of susceptible animals, 

 they are capable of causing tuberculosis in the creature 

 thus inoculated. This is considered to be a crucial test, 

 and has been successfully performed over and over again 

 by scores of competent observers in several different 

 countries. 



NO CONSUMPTION WITHOUT INFECTION. 



There are many causes which may predispose an in- 

 dividual to the development of tuberculosis ; but no one 

 of these, nor all of them combined, will suffice to deter- 

 mine an attack of this disease unless the bacillus tubercu- 

 losis is super-added. Lesions simulating tuberculosis 

 may be induced, but not the true disease. A minute 



