82 FUMIGANTS 



Sulphur 



Under some conditions a satisfactory fumigation may be had by 

 burning sulphur at the rate of 2 pounds to 1000 cubic feet. It should 

 be noted that the fumes are harmful to vegetation, that they will 

 bleach fabrics, and that they will destroy the germinating power of 

 seeds. As a means of killing bedbugs in empty rooms the treatment 

 is excellent. 



Place the sulphur in a fire-proof vessel, and this in turn within a 

 larger vessel, and ignite. Keep the place closed for 24 hours. 



Hydrocyanic Acid Gas 



The most active fumigating agent in use is hydrocyanic acid gas, 

 made by combining water, sulphuric acid, and potassium cyanide. 

 This gas is a deadUj 'poison to man as well as insects, and its use should 

 not be attempted unless careful precautions are taken, or the opera- 

 tor has had experience. It should never be used for fumigating any 

 part of an inhabited house, unless the entire premises can be vacated 

 for two or three days until the structure is thoroughy aired. 



For fumigating nursery stock, the materials are used in the propor- 

 tion of 1 ounce of 98 per cent potassium cyanide, 2 ounces of com- 

 mercial sulphuric acid, and 4 ounces of water for each 100 cubic 

 feet of space in the fumigating chamber. The chamber is kept closed 

 for 40 minutes. To generate the gas, have ready an earthen crock 

 of generous size. Pour the necessary amount of water into the crock, 

 and slowly add the sulphuric acid, stirring the mixture. Never re- 

 verse this order and pour the water into the acid. Considerable heat 

 will be generated. Place the proper amount of potassium cyanide in 

 a paper bag, or tie up loosely in paper, drop the package into the 

 crock, and at once leave the room, closing it up air tight. A con- 

 venient way of adding the cyanide is to suspend the bag over the 

 crock with a string, the other end of which is led through a small 

 hole in the fumigating chamber, so that the operator can retire first 

 and seal the door, and then lower the bag of cyanide into the acid. 



