DISINFECTION :;:>!) 



ticular purpose will depend on the conditions under which 

 il is to be used. If the room to be treated is so const ructed 

 that it can be made tight enough to retain the gas for some 

 liours, the use of formalin or sulphur is to be recommended. 

 The gas penetrates to every portion of the room, into cracks 

 and crevices into which it is difficult to- force a liquid. Gas 

 will not easily penetrate layers of clothing- and bedding, 

 so that the treatment of a living-room or bedroom with a 

 gaseous disinfectant will often not accomplish what many 

 conceive it will do. For the treatment of surfaces to which 

 a liquid can not be applied it is of the greatest value. 



The room to be treated should be made as tight as pos- 

 sible by pasting paper over the window and door cracks. 

 The gas can be liberated from the liquid by the use of per- 

 manganate of potash. One pound of formalin and one half 

 pound of permanganate will be needed for each thousand 

 cubic feet to be treated. The permanganate is placed in 

 a large pail and the formalin poured over it. A violent 

 chemical action results, and a portion of the formaldehyde 

 is set free. The room should be warm and the air moist 

 to obtain the best results. The room should be opened 

 for twenty-four liours. The gas has no harmful action on 

 objects except those of delicate leather. 



If sulphur is used, five pounds must be employed for each 

 thousand cubic feet. The sulphur should be placed in an 

 iron vessel, which should be set in a pan of water so that 

 the heat will evaporate a portion of the water, for it is 

 essential to have a considerable amount of moisture in the 

 air if the sulphur is to prove effective. The powdered sul- 

 phur is ignited by making a depression in the center of the 

 pile and adding a small amount of kerosene, which is ig- 

 nited. The room should remain closed for twenty-four 

 hours. 



Stable disinfection. In the treatment of stables and 



