MILLS AND OTHER BUILDINGS 169 



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, (i) 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 directed, 

 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. The writer personally con- 

 ducted the fumigation of a five-story brick building in 

 Baltimore, September 18, 1900, infested with insects 

 {Lasioderma serricorne}, injuring leaf tobacco in store, 

 and the method was thoroughly successful. Fifty 



