176 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. 
‘* For each fumigation one-tenth (0.1) 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 sti%} 
hot and the building at once closed for the night.’’ 
