INTRODUCTORY NOTE. ix 



may be hidden away, or rather lie openly revealed, 

 before the final and apparently obvious step is taken 

 towards its practical application. In 1837, Schwann 

 clearly established the connexion between putrefaction 

 and microscopic life ; but thirty years had to elapse 

 before Lister extended to wounds the researches of 

 Schwann on dead flesh and animal infusions. Prior to 

 Lister the possibility of some such extension had 

 occurred to other minds. Penetrative men had seen 

 that the germs which produce the putrefaction of meat 

 might also act with fatal effect in the wards of a 

 hospital. 



Thus, for example, in a paper read before the British 

 Medical Association at Cambridge in 1864, Mr. Spencer 

 Wells pointed out that the experiments of Pasteur, 

 then recent, had 'all a very important bearing upon 

 the development of purulent infection, and the whole 

 class of diseases most fatal in hospitals and other over- 

 crowded places.' Mr. Wells did not, as far as I know, 

 introduce any systematic mode of combating the organ- 

 isms whose power he so early recognised. But, I 

 believe, in hardly any other department of surgery has 

 the success of the antiseptic system been more con- 

 spicuous and complete than in that particular sphere 

 of practice in which Mr. Wells has won so great a 

 name. 



A remark in the paper just referred to would seem 

 to indicate that, in regard to the further possible 

 influence of germs, the thoughts of Mr. Spencer Wells 

 had passed beyond the bounds of pure sirrgical prac- 

 tice. ' Their influence,' he says, • on the propagation of 



