CRESOLS 55 



pends upon the liberation of free chlorine gas, which 

 rapidly disappears when the lime is exposed, so that 

 the dry material must be kept covered and solutions 

 prepared as needed. It is destructive to fabrics. 

 A 1 per cent, solution will kill all non-spore-bearing 

 organisms in five minutes, and a 5 per cent, solution 

 destroys spores in one hour. Calcium hydroxide, made 

 by adding water to quicklime, is efficient against 

 typhoid bacilli in feces when a 20 per cent, solution 

 is added to thoroughly mixed feces in equal parts and 

 exposed one hour. 



Dr. Daken, working for the British Army, has 

 found that the addition of sodium carbonate to a solu- 

 tion of chlorinated lime, which mixture is neutralized 

 by boric acid, forms a highly efficient germicide for 

 wounds. It is not destructive to tissues, will pene- 

 trate, and may be used in high concentration, 1 to 20. 

 Its value lies in the hypochlorous acid which is liber- 

 ated in the tissues. 



Carbolic Acid or Phenol. This is a crystalline solid 

 which softens when exposed to the air. It is soluble 

 in 15 parts of water. It must be thoroughly mixed with 

 material to be disinfected. It is not destructive to 

 fabrics or colors. It acts best at about the body tem- 

 perature. It is not much affected by the presence 

 of organic substances. A 5 per cent, solution kills 

 spores in a few hours, and 1 to 1000 inhibits the growth 

 of all bacteria and may be considered as an antiseptic; 

 3 per cent, solutions kill the pus cocci in one minute. 



Cresols. These are thick, sticky, brown fluids related 

 to carbolic acid. They make a milky emulsion with 

 water. The best-known ones are tricresol, creolin, 



