242 MICE013ES, FERMENTS, AND MOULDS. 



CHAPTER VI. 



MEANS OF DEFENCE AGAINST MICROBES. 



I. ANTISEPTIC TREATMENT OF WOUNDS: GUE"RIN'S 

 PROTECTIVE DRESSING; LISTER'S DRESSING. 



THE first and most brilliant application of the theory 

 of microbes to human therapeutics has been made in 

 the treatment of wounds. 



Since it is admitted that the danger of a wound 

 or of a surgical operation is chiefly due to the contact 

 of the wound with the external air, which is laden 

 with germs, or with the dressing which may contain 

 microbes, all the surgeon's efforts should be directed 

 to preventing such contact. This may be accom- 

 plished by several processes, now generally employed 

 by surgeons, and these may be regarded as the noblest 

 achievement of modern surgery. 



In Guerin's protective dressing, this skilful surgeon 

 has made a practical use of Tyndal's and Pasteur's 

 researches into the nature of air-germs. We have 



