1 76 FUMIGATION METHODS 



it was opened and occupied during the day. The only 

 injurious effects of the gas were on the mice and in- 

 sects in the building, but the precaution had been taken 

 to remove the unused printing paper and dry plates 

 before the fumigation, although it is not definitely 

 known that they would have been injured by the gas. 

 The morning after the fumigation dead insects were 

 found lying everywhere about the building: flies had 

 dropped from the ceilings and windows, and mice had 

 come from their hiding-places and died. 



11 For each fumigation one-tenth (o.i) of a gramme 

 of potassium cyanide was used for each cubic foot of 

 space in the building. All the connecting doors were 

 opened. Four stone jars were placed one at each end 

 of the building on the two floors. No exact measure- 

 ment was made of the strength and quantity of acid, 

 but an attempt was made to use about the same weight 

 of commercial sulphuric acid as of potassium cyanide. 

 The commercial acid was diluted by pouring it into 

 the water which was placed in the jars first. The 

 cyanide was then dropped into the mixture while still 

 hot and the building at once closed for the night. ' ' 



