CHLORIDE OF LIME 51 



skin and fabrics, but it can be used with value in diphtheria. 

 Solutions should be freshly prepared in 1-2 per cent, strength. 



Copper Sulphate. This chemical is potent against typhoid 

 in water in the presence of little organic material in the 

 strength of 1 to 400,000 in twenty- four hours.. 



Sodium Hydroxide (caustic soda). This substance is very 

 destructive to fabric and to the skin, but kills, in the strength 

 of 1 to 100, vegetative bacteria in a few minutes, or spores are 

 destroyed by 4 per cent, solution in forty-five minutes. 



Sodium Carbonate. This chemical, advantageous for 

 boiling instruments, kills vegetative forms in 5 per cent, 

 solution very quickly, or spores in boiling water in about 

 five minutes. 



"Chloride of Lime" (chlorinated lime). This chemical is 

 also known as bleaching powder. There is a difference of 

 opinion as to its composition. Its power depends 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. 



There have lately been developed several disinfecting sub- 

 stances of especial value to surgeons, depending upon chlorin 

 for their action. They are: 



Dakin's solution, a solution of chlorinated lime, sodium 

 carbonate, and sodium bicarbonate so mixed that it has an 

 alkalinity of 0.45 per cent. When this solution comes in con- 

 tact with tissue, hypochlorous acid and chlorin are formed and 

 the antiseptic action occurs. Necrotic tissue is dissolved and 

 hidden groups of bacteria are exposed. The chlorin upon 

 which the antiseptic action depends is evanescent, so that the 

 fluid must be renewed frequently. The fluid should be pro- 



