COMMUNITY SANITATION 435 



common of these are unslaked lime, chloride of lime, 

 carbolic acid, mercuric chloride, sulphur, and formalde- 

 hyde. Great care should be taken in using these sub- 

 stances because most of them are poisons. Unslaked 

 lime may be scattered on the ground to disinfect damp, 

 filthy places. Chloride of lime is a good disinfectant for 

 garbage cans and closets. Carbolic acid, a very strong 

 poison, is a general disinfectant. A solution of it may be 

 used for many purposes : during house cleaning for wip- 

 ing up floors and washing out closets and cupboards; 

 as a disinfectant in cleansing wounds (weak solution) ; 

 to mix with the water in which clothes are boiled after 

 being used in the care of the sick. Mercuric chloride 

 (corrosive sublimate, a deadly poison) is used in much the 

 same way as carbolic acid. Its odor is not so strong, 

 and it is not so hard on the skin. 



Sulphur dioxide and formaldehyde are the chemicals 

 commonly used for fumigating. Sulphur dioxide is now 

 generally obtained by burning sulphur 

 candles, but is not of much value unless 

 the air of the room where it is burned is 

 full of moisture. This may be accom- 

 plished by boiling water for some time 

 previous in the room to be fumigated. 

 There is on the market however a com- 

 mercial fumigator which is quite satis- 

 . factory, the moisture being secured by 

 setting the fumigator in water. For- FIG. 383. AForm- 

 maldehyde is a better disinfectant than aldehyde candle ' 

 sulphur dioxide. It is also used in the form of candles 

 (Figure 383), but it is more commonly used in the form 

 of a liquid solution. Cloths are dipped in the solution 

 and are then hung in the room which is to be disinfected. 



