STERILIZATION 25 



Silver salts. The silver salts, as silver nitrate, argyrol and protargyrol, are 

 of a special value as disinfectants for some of the cocci. This fact explains the 

 extensive use of these chemicals in the treatment of gonorrheal ophthalmia 

 and certain types of sore throat. 



The Halogens. Perhaps more commonly used than any of the foregoing 

 inorganic disinfectants are the free halogens, notably iodine and chlorine, and 

 to a minor extent free bromine. 



Iodine, both as terchloride of iodine (IC1 3 ) and free iodine are extremely 

 strong disinfectants. Tincture iodine (U.S.P.) or 10 per cent, is a simple and 

 most efficient method of sterilizing the skin. 



Chlorine, both free and available, is perhaps one of the most common of 

 inorganic germicides. 



Chloride of lime, or the so-called "bleaching powder," is a substance, 

 possessing probably the formula CaOCl2. The action of dilute acids or air (in 

 which we find COz and moisture, thus forming carbonic acid) upon this substance 

 results in the liberation of chlorine, so termed "available." The latter, because 

 of its readiness in destroying vegetative forms of bacteria, when even in dilute 

 solutions, has brought about the extensive use of this chemical in the disinfec- 

 tion of sewage and water supplies. 



. A preparation which has been known for years, but recently exploited and 

 used more extensively, is the Dakin-Carrel solution. This product is made like 

 Labarraque's solution of the United States Pharmacopeia, but possessing special 

 precautionary differences, as may be observed below, where follow its details 

 and mode of preparation. As this solution liberates its chlorine when in contact 

 with wounds and retains its antiseptic properties for a long time, it will be valu- 

 able only when it is in no way harmful to the cells of the surrounding tissues. 

 This can be taken care of by observing that the concentration of available chlo- 

 rine be uniform and of the standardized strength, and that the product be free 

 from irritating substances, as free alkali, boric acid, etc. This preparation, 

 when used in surgery, is employed by immersing a]l the wound surfaces 

 through a constant flow, maintained by a hydraulic system. At the same 

 time, all portions of the skin surrounding the wound are protected from ex- 

 posure to the chlorin solution, by having applied to it sterile gauze strips 

 with vaseline. 



PREPARATION OF DAKIN'S SOLUTION (DAUFRESNE'S TECHNIQUE) 



Original letter by Dr. Carrel 

 (Journal of the American Medical Association, Dec. 9, 1916, p. 1777) 



"Dakin's solution is a solution of sodium hypochlorite for surgical use, the 

 characteristics of which, established after numerous tests and a long practical 

 experience, are as follows: 



(a) "Complete Absence of Caustic Alkali. The absolute necessity for em- 

 ploying in the treatment of wounds a solution free from alkali hydroxide excludes 



