2l8 MANUAL OF BACTERIOLOGY. 



immersion for half an hour in this solution rinse thoroughly 

 in sterile water and put in a i-iooo bichloride of mercury 

 solution for twenty-four hours. Remove and place in 1-20 

 carboUc acid solution until required for use. At operation 

 remove from solution, rinse out in normal salt solution, and 

 place in receptacle filled with salt solution. If sea sponges 

 are used on a septic case, they should be thrown away and 

 no attempt made to resterihze them. If used on clean cases, 

 they may be resterilized as above. 



Dressings. The two materials universally used to dress 

 wounds are "gauze" or cheesecloth and absorbent cotton. If 

 they are properly sterilized, the impregnation of gauze or 

 cotton with antiseptics does not add to their value. Gauze 

 is usually cut in yard squares and folded compactly so as to 

 make compresses. A number of compresses are wrapped with 

 a piece of cotton cloth and the edges stitched loosely into a 

 closed bundle. After sterilization by the fractional method, the 

 bundles can be placed in sterile jars or receptacles and each 

 bundle removed as needed. Ripping open the stitches gives 

 untouched sterile bundles of compresses, convenient and handy 

 for using. Cotton is sterilized by the fractional method in 

 rolls or bundles as for gauze. These dressings should be 

 warmed before being placed in the steam steriUzer or they 

 will be unnecessarily wet when removed. 



Irrigating solutions. Chemical germicides, such as bichlo- 

 ride of mercury when in solution, cause necrosis of tissue. 

 Plain sterile water causes maceration of epithelium. Normal 

 salt solution is the least irritating to the tissues and is the one 

 most generally employed for irrigating purposes. It is 0.6 per 

 cent, sodium chloride, prepared roughly by adding a teaspoon- 

 ful of salt to the pint of water. This solution may be steril- 

 ized by boiling for half an hour on three consecutive days. 

 It does not injure tissue, and may be freely used in operations 

 for irrigating. It has no germicidal or antiseptic properties. 



