156 FUMIGATION METHODS 
chance to use the gas in a granary and storehouse. 
The results were so gratifying we decided to apply the 
same methods to a modern mill, if an infested one 
could be found and the owner would consent to the 
experiment. Two infested mills where we could try 
the gas on a large scale were soon found. Both 
contained three stories with basement and attic. One 
was 70 by 4o feet and the other 50 by 50 feet. Before 
filling an entire building with the gas, we decided to 
confine our experiment to one floor. All arrange- 
ments were made with a Pennsylvania miller and final 
directions were sent for the work. The first charge 
was set off June 10, 1899, using five pounds of 
potassium cyanide, an equivalent of o.10 gramme 
cyanide per cubic foot of space enclosed. 
Five days later the following letter was received. 
from the owner: ‘‘ We made use of the chemicals sent 
us, as directed, on the 1oth instant, and had some 
success, at least enough to convince us that through 
its use we can retain possession of our mill. Most of 
the weevil on the first floor are either on the floor or 
very close to it, and we find that a good many of them 
escaped punishment. In the rooms above the first 
floor we will have a better chance at them, they being 
higher up in places where we can not get at them 
with anything but gas. We would like to have you 
arrange to send us enough of the potassium cyanide to 
go through our mill from the first floor up. Any 
information you can give us concerning the second 
treatment will be greatly appreciated. We found a 
dead cat on the mill floor when we went in after airing 
the room thoroughly.”’ 
