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 faultentirely. Weagain 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 nsed hydro- 
cyanic acid gas successfully in a dwelling-house, wrote 
him for an account of his experience and received the 
following reply : 
‘‘T 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 roo 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 
