174 FUMIGATION METHODS 



fear but what we can keep our mill free in the future. 

 We removed all flour, with exception of a few samples, 

 but on these we could discover no taint. Our failure 

 before was owing to inferior cyanide, just as you said, 

 and was our chemist's fault entirely. We again thank 

 you for your advice and information. 



Successful application in house and laboratory. The 

 writer, knowing that Dr. H. J. Webber, of the United 

 States Department of Agriculture, who is in charge of 

 the Laboratory of Plant Breeding, had used hydro- 

 cyanic acid gas successfully in a dwelling-house, wrote 

 him for an account of his experience and received the 

 following reply : 



' ' I had one experience in Florida in fumigating a 

 rented house for various household vermin. While 

 such a matter is usually considered strictly a private 

 affair, I have no objection to giving you the following 

 brief note : While living in Florida we moved into a 

 house which was found to be infested with cockroaches 

 and bedbugs. In order to rid the place of these pests 

 it was fumigated with hydrocyanic acid gas, using one 

 ounce of potassium cyanide to each 100 cubic feet of 

 space in the house. The fumigation was started very 

 early in the morning and continued for about six 

 hours, when the windows and doors were opened and 

 the rooms thoroughly ventilated. The house was 

 occupied that night as usual, there being only a slight 

 odor of the cyanide perceptible. The effect of this 

 fumigation was marvelous. I have never, before or 

 since, seen a house so thoroughly cleared of insects. ' ' 



In the same letter Dr. Webber says they were 

 greatly bothered last summer, in their Washington 



