MILLS AND OTHER BUILDINGS 169 
a 
from a large number of individuals throughout the 
country, who have used hydrocyanic acid gas in mills, 
warehouses, elevators and other places, are sufficient 
to corroborate the statement that it is of very great 
economic value when used in such places. In quot- 
ing these letters all reference to individual and firm 
names has been omitted purposely. The following is 
a letter from a Utah milling firm who used this gas 
recently : 
We procured the necessary chemicals and proceeded 
to carry out your instructions specifically. We believe 
that we are safe in saying that the experiment was 
entirely successful, (1) because on leaving the build- 
ing, after dropping the chemicals into the water and 
acid, we heard the bubbling described by you, thus 
proving that action took place between the cyanide 
and the adulterated acid; (2) when we opened the 
door of the building, after leaving it closed as dire¢ted, 
two dead pigeons were found (we had placed them 
in the building purposely), the gas had entirely filled 
the enclosure, as the two birds were in different 
places in the rooms; and (3) the best proof that 
the experiment was successful is the fact that we 
cannot find any trace of the pests which formerly 
existed, even though warm weather is here. We 
wish again to thank you for the interest taken in this 
matter, as well as the favors extended to us. 
Tobacco warehouse.—TYhe writer personally con- 
ducted the fumigation of a five-story brick building in 
Baltimore, September 18, 1900, infested with inse¢ts 
(Lasioderma serricorne), injuring leaf tobacco in store, 
and the method was thoroughly successful. Fifty 
