CHEMICAL DISINFECTANTS 141 



Alcohol. Ninety-five percent and absolute alcohols are not 

 antiseptic for the anthrax spores, since they will live for many 

 hours in contact with absolute alcohol. In general it is unreliable. 

 Seventy percent alcohol is the most efficient strength. 



Zinc chloride in concentration is a powerful germicide. A 2 per- 

 cent solution will kill the ordinary pyogenic bacteria in two hours. 



Sputum, urine and dejecta are best disinfected by heat. Chem- 

 icals often are inert because they cannot penetrate the albumi- 

 nous masses of the sputum or feces. Long contact with carbolic 

 acid acidulated with HC1 is very efficient. Concentrated forma- 

 line and solutions of chloride of lime may be used, also a heavy 

 mush of lime in water. 



Boiling or heating instruments and dressings by high moist heat, 

 as in an autoclave, is the most reliable method of rendering them 

 sterile. The exposure of dressings to i5oC. for one hour, or 

 boiling instruments, thoroughly cleaned mechanically, for twenty 

 to thirty minutes makes them certainly sterile. 



Disinfection of the skin is a difficult undertaking from a 

 bacteriological standpoint. In the deep layers of the skin, and in 

 the sweat glands and hair follicles, bacteria often exist, even after 

 the most thorough and prolonged disinfection. The application 

 of soap and water with a stiff brush is by all means the most 

 valuable part of the process, since with the removal of the dirt 

 most of the bacteria are removed. Thorough scrubbing with soap 

 and sterile water, followed by scrubbing with a 1-1,000 bichloride 

 solution, cleansing the nails with a sterile brush, and prolonged 

 immersion in bichloride or permanganate of potash solution, 

 complete the process. Modern methods, even after all this 

 preparation, require the use of rubber gloves that have been 

 sterilized by boiling. The faultiest part of the preparation for an 

 aseptic operation from a bacteriological standpoint, has always 

 been considered to be the sterilization of the hands, and if these 

 can be covered by rubber gloves that are sterile, the fault can be 

 surely eliminated. 



