238 FUMIGATION METHODS 



" One form of fumigating box in use by some of 

 our nurserymen deserves notice. It consits of a 

 smaller box resting inside of a larger one, about six 

 inches of space separating the two between the bot- 

 toms and about the sides, which is filled with loose 

 sand or clay. The top is either constructed with a 

 similar space filled in with sand or earth, or may be of 

 the usual pattern double-boarded with tarred paper 

 between. This lid has a rim of beveled inch-board six 

 inches deep, projecting downward and falling into the 

 sand above mentioned, being brought perfectly into 

 place by a wooden wedge above. This produces a box 

 that is absolutely air-tight, and can never have an 

 unsuspected leak of any kind in it. 



" Judging from the evidence in my office, the gas 

 treatment carefully applied is absolute protection 

 against San Jose scale and other insect pests upon 

 nursery stock. I have known instances where much 

 nursery stock had gone forth infested when fumiga- 

 tion was either not practiced at all or was carelessly 

 done, but have failed to learn of a single case of 

 infested stock going out from the same nurseries after 

 the stock was carefully treated." 



Idaho. No experimental work with hydrocyanic 

 gas has been done at this station. The question of 

 infested nursery stock has not been a pressing one. 

 In this state I knew of one infested nursery, but it 

 was abandoned. The owner made some inquiries of 

 me about the subject of fumigation, and constructed a 

 fumigating room, which he used for a year or two 

 with success. As to fumigation of commercial 

 orchards, there has been none of it here so far 



