INTRODUCTION XX1X 
the inhibitory action of antiseptics on the growth of bacteria, as distinguished 
from their destructive action.' 
Apart from these experiments 7 vitvo, it must be realized that the intro- 
duction of the antiseptic system was one vast experiment on the living body. 
Up to that time, with perhaps the exception of observations by Davaine upon 
anthrax, no work had been done which demonstrated any pathogenic action of 
bacteria. Indeed during the early development of antiseptic surgery the question 
of pathogenic bacteria, as we now know it, did not arise. In the first instance 
it was ‘putrefaction’ in the discharges of a wound which was attacked, and 
though this was looked on as due to the bacteria present in these discharges, no 
classification of these bacteria into species was thought of, and no differentiation 
into pathogenic and non-pathogenic organisms was made. It was simply a case 
of preventing the entrance of bacteria as a class into wounds and their develop. 
ment there. Very soon, however, we find Lister pointing out that there must be 
different species of bacteria, and that putrefaction was not the only injurious fer- 
mentation which might occur in wounds, for he noted that in some cases, although 
there was no odour in the discharges, suppuration nevertheless occurred; thus, 
in a footnote toa paper published in 1870? he says: ‘ This group (cases of putre- 
factive suppuration) ought to include the products of other ferments besides those 
of putrefaction, for I am satisfied that inodorous ferments sometimes occur in 
the animal fluids and produce salts which stimulate to suppuration ; also viruses 
inducing suppuration are very probably of the same essential nature (ferments), 
though some at least are odourless, as in the case of erysipelas.’ It is true that 
he attributed the odourless suppuration in some of these cases to reflex distur- 
bance of the nervous system, produced, for example, by tension in the wound, vet 
at the same time he recognised that, in some instances at any rate, it was due to 
bacterial infection. Indeed it was more especially with the view of demonstrating 
that there are different kinds of bacteria, each with its own fermentative action, 
that he undertook his work on lactic fermentation. Very soon also we find him 
beginning to realize the possibility of the penetration of bacteria into the bod 
from the wound, and thus the distinction between pathogenic and non- 
pathogenic bacteria. 
Under the system he evolved not only did inflammation and suppuration 
disappear, but also pyaemia, hospital gangrene, erysipelas, and tetanus. In his 
demonstrations at the hospital he was fond of pointing out how erysipelas spread 
like fairy rings, as if the organisms which produce it were advancing in the tissues 
before the redness and dying out behind it, a view strikingly confirmed sub- 
sequently by Koch and others. He also remarked, with some diffidence it is true, 
A Wolrt. pe 273: * Vol. il, p. 140. 
