242 MICROLGES, FERMENTS, AND MOULDS, 
CHAPTER VI. 
MEANS OF DEFENCE AGAINST MICROBES. 
I. ANTISEPTIC TREATMENT OF WouNnDs: Gu#RIN’s 
Protective Dressine; 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 Guérin’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 
