60 THE STORY OF THE BACTERIA. 



bacteria or something else, which so gained 

 entrance to the body, no one knew. But the 

 surgeons did not wait until they should know 

 all about the cause of the trouble, but began 

 to apply to the wounds such materials as would 

 actually kill germs, or, at any rate, keep the 

 wounds free from putrefactive changes. Car- 

 bolic acid, dissolved in water, was found to be 

 efficient in this way in washing the wounds. 



Then, as it seemed more and more as if the 

 trouble were due to living germs falling upon 

 the wounds from the air with the dust, it be- 

 came the practice, when surgical operations 

 were being done or wounds dressed, to spray 

 carbolic in the air about the operator's hands 

 and over his instruments and upon the wounds, 

 and when the bandages were put on to seal 

 them in tightly, so that no germs could gain 

 access to the wound while the healing went 

 on. All this time the particular species of 

 bacteria which produced the trouble remained 

 entirely unknown ; indeed, it was only an 

 hypothesis that the disease was due to germs 

 at all. 



A great deal of careful laboratory work has, 



