Introductory Address Delivered in the Medical Department of King's College
Authors: J. Lister
Journal: BMJ (1877)

GENTLEMEN,-In making myefist appearance -as 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 beneficent 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 instruc- tion, not only for the student, but also for the 'entinent -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 in- terval between the cessation 'of my official duties in Edinburgh and-their commencement here.The-object of that investigation 'was to obtain, if possible, some positive and definite knowledge of the essen- tial nature of a class of phenomena which interest alike the physician, the surgeon, and the accoucheur.I allude to the changes in organic ,substances which are designated by the general term fermentation.In medicine, 'the'large class of diseases termed zymotic'derive their flame from !the hypothesis that their essential nature is fermentative.'In obstetrics, puerperal fever, the most frequent cause of lisaster after childbirth, is now regarded by many of the highest authorities as 'likewise due to fermentative disorder; 9nd, in surgery, among the 'various causes which may disturb -a wound, we know that by far the most frequent in operation, and the most pernicious agent in its effects both upon the wounded part and upon the constitution, is putrefactive fermentation.If this be so, it is clear that to understand the nature of fermentation must be a matter of the very highest importance, with a -view to curing or preventing the various evils to which I have 'alluded.What, then, do-we mean by fermentation?I shall best approach the answer 'to this question by giving an example.Ruther more than a week ago, I witnessed in the north of Italy the time-bonoured prac- tice of treading grapes in the wine-vat.I was told that the juice would within twentyfour hours boil, as it was said, over the vats into which it was -introduced; in other words, 'that the sugar of the grapejuice would within that short time be so converted into alcohol and 'carbonic acid gas, that 'the carbonic acid gas, by its ebullition, wouldCause sufficient frothing to produce the efect to which I have Teferred.'This conversion of the sugar of the grape into alcohol and car- bonic acid 'gas is accompanied by the development of a microscopic -organism, the yeast-plant, or, to!continue the old nomenclature, Totula cerez'iraz, consisting -of microscopic cells multiplying by pullulation, as indicated in this rough diagram.Now, it is, I believe, universally ad- mitted that -the alcoholic fermentation of grape-sugar is 'due to the growth of the yeast-plant.M. Pasteur thinks that he has traced -the origin of the yeast-plant in the juice of the grape to a minute fungus adhering to the outside of the skin 'of the grape.Be this as it -may, it is admitted on all hands that the alcoholic 'fermentation is caused by the growth of the yeast-plant.-So long-as the juice of the grape is protected by the skin of the berry, no fermentation occurs; but, as soon as it escapes from that protection, the organism, by its develop--ment, induces the fermentation.Nor is it by any means exclusively in the natural juices of fruits that such fermentation is induced.Any