342 



THE CA.NAD1AN ENTOMOLOGIST. 



being that we consider 30 cc. as the equivalent of a fluidounce. It takes 

 about 340 pounds of cyanide (98% pure) and the same quantity of 

 sulphuric acid to give the building a single treatment, not including the 

 halls, which are thoroughly scrubbed with lye and water. 



, Our first work was to measure the rooms and compute the cubic 

 contents of each. With the exception of a few corner rooms, they are as 

 follows : 



In computing the amounts of cyanide, water and acid to be used, we 

 always raise the cubic feet in any givv^n room to the next even hundred. 

 For example, the capacity of each room on the fourth floor, which is 

 i960 cubic feet, was considered to be 2000 cubic feet. 



In the fumigation we attempted to treat one-fifth of the building each 

 successive day. It is to be noted that there are three wings and a long 

 front, twice as long as each wing. This affords a natural division of the 

 building into five parts, each division containing an average of about 50 

 rooms. We begin on one wing by setting six men to caulking the windows 

 and transoms with strips of newspaper about four inches wide and 

 thoroughly soaked in water. The paper is first torn into strips and then 

 placed in pans of water, where it is allowed to remain until thoroughly 

 soaked. These wet strips are then quickly and effectually applied to the 

 top, bottom and sides of eacli window and transom or other cracks that 

 may be found in the room. 



At the same time two men are placing ordinary china wash-bowls in 

 each room with the proper amount of water and acid in each. Beside 

 each bowl is also placed the proper amount of cyanide on a piece of 

 newspaper spread flat on the floor. 



We usually try to begin at such a time in the day that the rooms in 

 one wing will be ready for fumigation at about 6 p.m. It takes the force 



