270 INFECTION AND IMMUNITY 



attached to the skin. Usually this is followed by 

 washing with alcohol and sterile water to remove all 

 traces of the antiseptic. Many surgeons at the pre- 

 sent day prefer to wear india-rubber gloves while 

 operating, as it has been found by experience that 

 it is a difficult matter to thoroughly sterilise the 

 hands. Such gloves are easily cleaned and sterilised. 

 By the " field of operation " is meant the surface of 

 the body in the vicinity of the incisions which are to 

 be made in any surgical operation. This surface is 

 cleaned as thoroughly as possible and other portions 

 of the body are covered with a clean sheet or sterile 

 towels. When the operating-room and its fixtures 

 are " surgically clean " and all necessary precautions 

 are taken with reference to instruments, dressings, 

 the surgeon's hands, etc., an operation wound is ex- 

 pected to heal promptly by adhesion of the wound 

 surfaces, which have been brought together and re- 

 tained by sutures or adhesive plaster, and bandages 

 when necessary. 



Such wounds treated aseptically rarely suppurate. 

 When they do it is because some of the bacteria 

 which cause pus formation have found their way into 

 the wound in spite of the precautions taken. It is 

 more difficult to prevent suppuration in gunshot 

 wounds and in extensive lacerations resulting from 

 railway accidents, etc. The bruising of the tissues in 



