for the year 1882. xxiii 



sumption is now admitted on all hands to be contagious. 

 For the last twenty years the contagiousness or infectious- 

 ness of this disease has been suspected, and various experi- 

 ments have more or less satisfactorily demonstrated its high 

 probability. Creighton, Burdon-Sanderson, Giboux, Martin, 

 and more recently Klebs, Cohnheim, and others, advanced 

 still another step in the same direction, but it has remained 

 for •Professor Koch, of Breslau, now chief of the Imperial 

 Medical Department of Berlin, to demonstrate it as a germ 

 disease, transmissible by inoculation, and that its con- 

 tagiousness is due to a form of bacillus, one of those low 

 orders of germs which appear to be at the bottom of many 

 diseases to which the human, as well as other animals are 

 prone. Now, assuming this to be the case, such knowledge 

 gives great strength, for the modes of resisting contagion 

 offer at once a prospect of, in some degree, stemming the 

 onward course of this destroyer. And, again, if it should be 

 further shown, as we may reasonably hope, that being a con- 

 tagious germ disease, it is not a hereditary one, then we 

 may cheerfully anticipate that science will find effective 

 weapons to check the spread of this fatal disease. 



Speaking of this brings to my memory a brochure pub- 

 lished six years ago (1876) by Mr. Wm. Thomson, of South 

 Yarra, entitled, Histo- Chemistry and Pathogeny of 

 Tubercle, which I referred to in a former address. In this 

 pamphlet he discusses at length the pathogeny of tubercle, 

 and gives his reasons for concluding it to be a purely germ 

 disease. On page 27 he says — " The idea of micrococci 

 being in any way associated with the process of tuberculosis 

 is a recent one ; and the explanation of their mode of opera- 

 tion is, at least as far as I am aware, now for the first time 

 in the history of pathology attempted, with what degree of 

 success remains to be seen." What has now been demon- 

 strated by Koch was undoubtedly indicated as of the highest 

 probability in Thomson's pamphlet of 1876, and reiterated 

 at greater length, and with fuller illustrations in another 

 pamphlet in 1879, and afterwards by Cohnheim in his work 



