142 



H. F. Formad, 



important rôle in phthisis, — viz., perhaps conditions the fatal issue 

 of the disease. Bacteria appear to effect the complete destruction of 

 diseased tissues which, without being infested by them, would recover 

 to a normal state or transform into a harmless tissue (fibroid tu- 

 bercle). Tissue -destruction seems to stand in direct proportion to 

 the quantity of these organisms, which thus regulate the prognosis. 



The study of bacteria as causa mortis is by no means less im- 

 portant than that as causa or materia morbis. 



In the present communication I have given the mere outlines of 

 the natural history of tuberculosis. I reserve it for future communi- 

 cations to give the details of the various parts of this research. The 

 next paper will embrace a detailed account of the structure of scro- 

 fulous tissues, with appropriate illustrations', so as to facilitate to 

 others the perusal of my work. 



