1 70 FUMIGATION METHODS 



pounds of cyanide wei^ used in this building at one 

 time. The four upper stories were fumigated first, 

 and a few days later the basement and first floors. 

 We demonstrated that this gas can be used even in the 

 heart of a solidly built-up city block if properly 

 handled. The building in question is located in the 

 heart of the business center of the city. Bvery crack 

 about the windows was pasted up with narrow strips 

 of paper. We used string and bags, suspending 3^ 

 pounds of cyanide over each four-gallon jar. We had 

 six jars each on the second and third floors and two 

 each on the fourth and fifth floors. The gas was gen- 

 erated after office hours at 7.30 and the windows were 

 lowered from the outside about 12 o'clock, midnight, 

 the same night. The windows in the fifth story were 

 lowered first, and by opening a door below a draft was 

 created through the elevator shaft carrying the bulk 

 of the gas out above the building. The other windows 

 were opened a few minutes later and the building 

 aired the rest of the night, one man remaining on 

 guard all the time. The results were very gratifying. 

 The pests were thoroughly destroyed, and in addition 

 seven dead rats were found on the basement floor and 

 one on the third floor. 



Mills and elevators. The following is from a Cana- 

 dian firm : In connection with our use of hydro- 

 cyanic acid gas for the extermination of the Mediter- 

 ranean flour moth, we beg to report the following : 

 The cubic contents of our buildings figure 290,472 

 cubic feet, for which we used 151 pounds cyanide of 

 potassium, 226 pounds sulphuric acid, and 338 pounds 

 water. We distributed 150 crocks throughout the 



