54 STERILIZATION AND DISINFECTION. 



hand over the site of operation, the warmth of the hand soft- 

 ening the gum sufficiently to make the rubber adhere firmly 

 to the skin. It is treated just as the skin would be ordina- 

 rily, and when the wound is sutured it is included in the 

 sutures. When the stitches are removed, it is pulled off like 

 a porous plaster. The advantage claimed for it is that it can 

 be sterilized properly, which the skin cannot, and thus insure 

 absolute cleanliness of the wound and field of operation. 



Hands of operator: The disinfection of the hands of the 

 operator and his assistants is a very important matter, and 

 many methods are in vogue aiming to procure absolute asepsis 

 of the hands. It is theoretically impossible to do this, be- 

 cause of the many crevices in the surface epithelium and 

 under the finger-nails, which afford secure lodgement to all 

 kinds of bacteria. Cultures of pathogenic bacteria have been 

 obtained from the skin and from under the nails after the 

 most thorough attempt at disinfection. 



The method most employed at the present time is that 

 recommended by Welch. After having trimmed and cleansed 

 the nails the hands are washed and scrubbed with soap and 

 water, the water of as high a temperature as can be borne, for 

 at least ten minutes, and then rinsed in clean water. They 

 are then immersed in a warm saturated solution of potassium 

 permanganate for five minutes, washed in oxalic acid to 

 remove the stain of the permanganate, and then in warm 

 water or salt solution, after which they are soaked for two 

 minutes in a 1 : 500 mercuric chloride solution. They may 

 then be considered sterile. The hand-brush must be sterile, 

 and should be kept in a 1 : 1000 biniodide of mercury 

 solution. 



Another method is to scrub the hands with green soap and 

 water and then immerse them for two minutes in a solution 

 of biniodide of mercury in methylated spirit, after which they 

 are rinsed in a 1 : 2000 biniodide of mercury solution. The 

 objection to the mercury salts is that they crack the skin. 

 Many surgeons cannot tolerate them at all, and for that reason 

 the permanganate is preferred. Every surgeon has a method 

 which he believes the best. Personal experience will govern 

 the choice of a method. 



