344 . THE CANADIAN ENTOMOLOGIST, 



Although it took about one hour to treat each floor, not the sHghtest 

 inconvenience or annoyance was experienced by the men from the gas on 

 the floor or floors above. There is also another advantage in this method : 

 Where the sun shines in windows the strips of paper, although we use 

 three thicknesses and soak them thoroughly, are apt to dry and curl away 

 from the cracks if left too long. By treating a floor as soon as ready we 

 obviate this difficulty and get the full effect of the gas. 



Some Results of the Use of This Gas Against Bedbugs Under 



Varying Conditions. 



Desiring to know the effect of hydrocyanic acid gas on bugs hidden 



away in mattresses, blankets, comfortables, etc., we tried the following 



experiments : 



1. Three bugs were placed in a perforated pill box and then wrapped 

 in excelsior, three inches all around, and this in turn in some domestic to 

 imitate ticking. 



2. Three bugs (one adult, one one-third grown and one very young) 

 were placed in a similar box and then carefully wrapped in two folds of a 

 thick comfortable. 



3. Three bugs (two adults and one one-third grown) were placed in a 

 similar box and carefully wrapped in cotton-batting to the depth of two 

 inches. 



4. Two bugs (one adult and one two-thirds grown) were placed in a 

 similar box and wrapped in two folds of a thick woollen blanket. 



5. Six bugs were put in a vial 3^ inches deep and one inch in 

 diameter, and the latter stopped with an inch cork which had been 

 punched twice with a pair of dissecting-forceps with curved points. The 

 holes thus made had apparently closed up owing to the spongy nature of 

 the cork, but I found afterwards that I could readily force air through 

 them by placing the cork between my lips. 



6. To serve as checks several bugs in perforated boxes were placed 

 about the room at different heights from the floor. 



In every box of bugs wrapped in different materials several new-laid 

 eggs were placed to determine the effect of the gas upon the hatching of 

 the same. 



The room in which the fumigation was done measured 14x8x8, and 

 contained 896 cubic feet. We used 10 ozs. of cyanide, 300 cc. of acid 



