CEREAL PESTS INSECTS 503 



cyanid required for each floor is usually about as 

 follows : - 



Basement, 1 pound to each 1000 cubic feet 



First floor, 1 pound to each 1200 cubic feet 



Second floor, 1 pound to each 1300 cubic feet 



Third floor, 1 pound to each 1500 cubic feet 



Fourth and fifth floors, 1 pound to each 1600 cubic feet 



The 4-gallon stone jars are placed in rows through the 

 length of each floor of the building and the 9 pints of 

 water poured into each one, the number of jars depending 

 upon the number of cubic feet in each story. The sulfuric 

 acid is added slowly after the water. When the building 

 has been made tight, and all of the jars have been prepared, 

 the cyanid is placed carefully but quickly in each jar, begin- 

 ning at the top story at the end opposite the door, and 

 going through each story regularly in the same manner 

 down to the basement. It should be remembered in the 

 application of this gas that it is extremely poisonous, and 

 one full breath of the gas after liberation in an inclosure 

 may prove fatal. The building fumigated should be 

 thoroughly ventilated for an hour or more by drawing 

 down a number of windows on each floor from the out- 

 side before human beings are allowed to enter. The 

 windows may be fitted with strings reaching to the 

 ground, and permitting the lowering of the top sash for 

 this purpose. To produce good results the building should 

 remain tightly closed for 8 hours or more after dropping 

 the bags into the jars. 



Baking tests have been made with the different grades 

 of soft and hard winter wheat flour fumigated with hydro- 

 cyanic acid gas, and not fumigated, and the results showed 

 absolutely no deleterious effect from the fumigation in 



