Lord Lister. 



v 



nature to certain fermentations, among others to putrefaction, and his 

 evidence that these bodies were derived from the dust floating in the air and 

 deposited on surrounding objects, he saw at once that he had found the 

 thing that was wanting. Pasteur's researches showed him that this 

 something for which he had been searching must be a micro-organism, similar 

 to those which Pasteur had described, and a very cursory examination of the 

 discharges from the wounds showed him that they were teeming with 

 living organisms of this kind. Lister, therefore, at once concluded that the 

 cause of putrefaction in wounds, and of the various evils which followed that 

 occurrence, was the growth of micro-organisms in the wounds, that they were 

 derived from the dust in the air and from surrounding objects, and that if he 

 could only prevent the access of these organisms in a living state or destroy 

 them after they had entered the wounds, he might possibly prevent a great 

 many of the evils which followed injuries or operation. 



At first, however, Lister had no idea of the far-reaching nature of this 

 conclusion. All that he could say at that time was that, in his experience, 

 these infective diseases did not occur in connection with wounds, such as 

 subcutaneous ones, in which putrefaction of the discharge had not occurred, 

 and he hoped that the same would be the case if he prevented putrefaction in 

 his wounds ; his whole aim, in the first instance, was, however, to prevent 

 putrefaction. Nothing was known at that time of the nature of the various 

 infective diseases which occurred in wounds, or their relation to bacteria ; 

 indeed, the idea that disease could be due to the growth of any such minute 

 parasites as bacteria had hardly been suggested. It is true, as we have just 

 said, that Davaine, some years before, had pointed out the presence of large 

 numbers of rod-shaped bodies, or vibrios, in the blood of animals which died 

 of anthrax, and he had somewhat timidly suggested that possibly the 

 presence of these vibrios was an essential element in the production of the 

 disease, but this suggestion attracted practically no attention, and it was not 

 until some ten years after Lister's work began that proof was furnished that 

 anthrax was due to the growth of these organisms, which were subsequently 

 named " anthrax bacilli." That pyaemia, septicaemia, hospital gangrene, 

 tetanus, erysipelas, diphtheria, and so on, were similarly due to the growth 

 of micro-organisms in the blood and tissues had not occurred to anyone, and. 

 indeed, did not definitely take root in Lister's mind for some time after he 

 commenced his antiseptic treatment. Nevertheless, Lister had arrived at 

 very definite conclusions on this point, as the result of his experience with the 

 pew methods of treatment, long before the part which the various micro- 

 organisms played in the production of disease had been demonstrated. 



Let us return, however, to the point when Lister, as the result of his study 

 of Pasteur's researches on fermentation and spontaneous generation, acquired 

 the certainty that the cause of putrefaction in wounds was the access of micro- 

 organisms from without. On reviewing the matter, he saw that the problem 

 of preventing the growth of micro-organisms in wounds was a complex one, 

 and that two different conditions had to be dealt with. On the one hand, the 



