INTRODUCTION XXVI1I 
their origin, and the reaction of the tissues to their growth, are all subsequent 
developments which have had their influence on the details of the method, but 
which have in no way affected the original Listerian principle. 
With the light thus shed on the problems on which he had been pondering 
for years, Lister at once threw all his energies into the application to the treatment 
of wounds of the principle established by these researches in vitro. It was 
evident that filtration of the air which reached wounds was not a practical plan, 
nor could heat be used to destroy the organisms in all places from which they 
might contaminate the wounds, for these organisms were not merely floating 
in the air, but were deposited on all surrounding objects, and to operate in an 
atmosphere of filtered air, or of air previously subjected to heat, could not meet 
the requirements of the case. Hence he turned to the search for chemical sub- 
stances which possessed the power of destroying these living particles. About 
that time experiments had been made at Carlisle on the disinfection of sewage by 
German creosote, the active agent in which was crude carbolic acid; the interesting 
results so obtained suggested to Lister that this substance might serve his purpose, 
and he accordingly procured a supply. He determined to test the new principle 
first in the treatment of compound fractures, the results in these injuries being 
especially bad at that time in his wards. He had to wait some months before 
he could put his ideas into practice, but at length the opportunity came, and on 
the 12th of August, 1865, he was able to put the matter to the test, with results 
which amply justified his hypothesis. It is very curious that the material thus 
more or less accidentally selected in the first instance as an antiseptic has turned 
out to be the most suitable of any yet known and tested for various purposes 
in connexion with the asepsis of wounds, especially for the disinfection ot 
the skin. 
Now followed a period of the most remarkable activity, involving an amount 
of mental exertion and patient toil which probably no other man would have had 
the genius or indeed the physique to carry through. Lister came to this work 
equipped in an entirely exceptional manner. Endowed with extraordinary mental 
insight, and provided with much physiological and chemical knowledge, he had 
spent years in considering and investigating the subject of wounds, and he was thus 
able to grasp the significance of the numerous new phenomena which he observed 
while carrying out his methods of treatment. During this early period every case 
contributed fresh information, and led to constant improvement in his attempts 
to imitate nature’s processes, and this constant modification of his methods in 
accordance with fresh observations is remarkable evidence of his clearness of 
vision, and a striking proof of the elasticity of his mind and of the absence ot 
bias. To the very end of his active work as a surgeon he was never entirel\ 
