DISINFECTION. 397 



popularity is the fact that it possesses a distinct odor, since 

 most people who do not understand the matter have a feeling 

 that a disinfectant having a strong odor must be efficient. 

 Carbolic acid acts as a deodorant and an antiseptic at the same 

 time, and has consequently been popular. 



Chloride of Lime. This is one of the cheapest and, at the 

 same time, one of the best disinfectants. It has been widely 

 used. It may be applied dry if the material to be disinfected 

 contains some moisture. But, since it acts only in the presence 

 of moisture, it may be best used in a water solution. A solu- 

 tion of i pint to 25 of water (i pound to 6 gallons of water) is 

 most commonly used, and this is very efficient for disinfecting 

 walls, floors and furniture that can be washed by it. It owes 

 its efficiency as a disinfectant to the chlorine gas which is 

 liberated from it. Common slacked lime, which is very com- 

 monly used on the farm as a whitewash, is of far less value as 

 a disinfectant. It liberates no chlorine and does not act like 

 chloride of lime. Its cheapness makes it possible to use it in 

 large quantities, and it can be used under conditions where 

 other disinfectants are impractical. But its disinfecting power 

 is small. 



Sulphur. The fumes of burning sulphur have been widely 

 used for disinfecting rooms, inasmuch as they are most easy of 

 application. In a room which it is desired to disinfect there 

 are always many cracks and crannies which cannot be easily 

 washed with disinfecting solutions, and into which the fumes of 

 burning sulphur readily penetrate. It is so easy to shut up a 

 room and burn a quantity of sulphur in it, that the use of sul- 

 phur has been very popular and widely extended. Unfortu- 

 nately its efficiency is not so great as at one time believed. 

 When the room to be disinfected is tightly closed and a suffi- 

 cient quantity of sulphur is burned in it, the fumes of sulphur 

 do destroy most of the bacteria, except the very resisting 

 spores. But under ordinary conditions it does not kill all 



