Household Pests and Their Treatment. 83 



rooms infested with roaches. This involves some expense and 

 trouble, but may in exceptional cases be the only recourse. A 

 case of this sort occurred recently at Lexington. A new brick 

 house occupied by a family of careful people became so com- 

 pletely infested that m desperation they applied to us for as- 

 sistance. The house measured about 40 by 40 feet and was two 

 stories high. It was fumigated with the following: 



Sodium cyanide, 20 Ibs. av. 



Commercial sulfuric acid, 3.75 gals. 



Water, 7.50 gals. 



This is at the rate of 1 ounce, av., of sodium cyanide, 1.5 

 ounces sulfuric acid, and 3 fluid ounces of water to each 100 

 cubic feet enclosed. It is more than is sometimes recommended, 

 but it is well to do thoro work and take no chances of fail- 

 ure, since this involves a complete loss of time, and money ex- 

 pended. The extra precaution is necessary because of the 

 difficulty of preventing leakage of the gas owing to badly fitted 

 doors, windows, etc. In a small room, well caulked, the fol- 

 lowing dose, sometimes recommended, will probably be found 

 sufficient. For each 130 cubic feet enclosed: 



Sodium cyanide, 1 oz. 



Sulfuric acid, 2 fluid oz. 



Water, 2 fluid oz. 



Small cupboards that can be tightly closed to prevent all 

 escape of fumes may be fumigated with bisulfid of carbon in- 

 stead of cyanide of sodium. This substance is sold as a fluid, 

 commonly in pound bottles, and it is only necessary to pour 

 the fluid in a dish or pan set on a chair or table and close the 

 door. The fumes are poisonous, and also very inflammable, 

 so that some care must be exercised to prevent their escape 

 into rooms other than those being fumigated, and also to keep 

 fire in any form away from them. The odor of bisulfid of car- 

 bon is disagreeable, but soon disappears when fumigated quar- 

 ters are thoroly aired after the fumigation is completed. 

 About 1 pound of bisulfid of carbon is used for each 500 cubic 

 feet of space enclosed and the strong fumes should be kept con- 

 fined or 48 hours. 



