ON THE NATURE OF FERMENTATION. 177 



Seeing that splenic fever, pueumo-enteritis, and specific 

 septicaemia possess a great affinity in anatomical respects, 

 and seeing that in splenic fever and pneumo-enteritis the 

 matevies morbi is a definite species of bacillus — the differ- 

 ence of species being sufficiently great to account for the 

 differences in the two diseases — we may with some pro- 

 bability expect that also the third of the group, viz. specific 

 septicaemia, is due to a bacillus. This, however, remains to 

 be demonstrated. It seems, finally, justifiable to speculate 

 whether or not we have in these three varieties of disease " a 

 variation of species " in the sense of the evolution theory. 



On t/ie Nature of Fermentation. The Introductory 

 Address delivered in King's College, London, at the 

 opening of the Session, October \st, 1877. By Joseph 

 Lister, F.R.S. ; Professor of Clinical Surgery in King's 

 College, and Surgeon to King's College Hospital ; &c. 



[The followiug report has been revised and corrected by Prof. Lister for 

 publication in this journal. — Ed.] 



Gentlemen, — In making ray first appearance as a teacher in 

 King's College, I cannot refrain from expressing my deep sense 

 of the honour conferred upon me by the invitation to occupy the 

 chair which I now hold ; and, at the same time, my earnest hope 

 that the confidence thus reposed in me may not- prove to have 

 been misplaced. 



In considering how I could best discharge my duty as the 

 person selected to deliver the Introductory Address of the 

 Medical Session, I have felt that two courses were open to me : 

 either to spend the short but important time at my disposal in 

 an endeavour to convey to the student some sense of the exalted 

 privileges, and correspondingly high responsibilities, of the bene- 

 ficent calling to which he proposes to devote himself, or to treat 

 on some special subject, in the hope that I might say something 

 which should have interest and, if possible, even instruction, not 

 only for the student, but also for the eminent men whom I have 

 the honour to see around me. The latter is the course which I 

 have decided to follow, and the subject which I have selected is 

 a short account of an inquiry in which I have been engaged in 

 the interval between the cessation of my official duties in Edin- 

 burgh and their commencement here. The object of that in- 

 vestigation was to obtain, if possible, some more precise and 

 definite knowledge of the essential nature of a class of pheno- 

 mena which interest alike the physician, the surgeon, and the 



