DEPARTMENT OF SURGERY. 
725 
the substances which touch the wound and consequently our at¬ 
tention must centre upon them. The substances which contact 
wounds aie :— 
( a ) Air. 
( b ) Instruments. 
( c) Hands of the surgeon and assistants. 
( d) Surgical dressings. 
(1) Wadding. 
(2) Bandaging. 
(3) Sutures. 
(4) Occlusive plasters. 
(5) Drainage apparatuses. 
( e ) Accidental woundirg bodies. 
( f ) Antiseptic solutions. 
( g ) Cleansing materials. 
(1) Soap. 
(2) Water. 
( 3 ) Sponges. 
(4) Syringes. 
(5) Scrubbing brushes. 
( h ) The habitat of the wounded patient. 
(1) Hitter. 
(2) The floor of the stable. 
(3) The soil. 
(4) The sides of the stall. 
As the above mentioned items are the sources of wound in¬ 
fection we must next consider their dangerous properties and 
especially the best practical methods of rendering them innoc¬ 
uous. 
Air is everywhere and therefore contacts all wounds. As a 
carrier of infection into wounds it was suspiciously regarded in 
the very first attempts at antiseptic wound treatment, and as a 
consequence methods were inaugurated by which its infectious 
organisms could be destroyed or at least rendered innocuous. 
The room in which an operation was to be performed was 
sprayed thoroughly with carbolic solution. The same solution 
was also sprayed in the environs of the operating region during 
the entire procedure and until the occlusive bandage was ad¬ 
justed. Subsequent experiments, however, have shown this pre¬ 
caution to be superfluous, the air having been found to be less 
dangerous than was first supposed. The truth is air of a still 
room, free from dust or drafts that are capable of carrying dust, 
is a safe medium for exposing even the internal cavities. The 
