The water should be first poured into an earthen or granite ware 

 receiving vessel (do not use a metal one), the acid is then added and 

 finally the cyanide, as directed more fully below. Use .01 grams of 

 cyanide per cubic foot of space in the house or box to be fumigated. 

 When the amount of cyanide necessary has been determined, put it 

 in a paper bag. Close the ventilators and firmly fasten every door 

 of the house except the one used by the operator. When all is 

 ready, take the cyanide, fill the lungs with air, drop the cyanide into 

 the vessel containing the water and acid and leave the house imme- 

 diately, lock the last door and notice the time. 



After the required time has passed, open the doors and give the 

 gas plenty of time to escape before you enter. This gas is very 

 poisonous, so do not enter the house during treatment. Fumigate 

 after sunset, allowing three hours exposure. In ventilating after- 

 ward, the amount of aitificial heat that can be supplied and the out- 

 side temperature must be taken into consideration, so that no injury 

 to the plants will result from the lowering of the temperature. Three 

 such treatments, at intervals of about twelve days, will usually com- 

 pletely rid the house of the white fly. 



Johnson's work entitled "Fumigation Methods'" is indispensable 

 to anyone who has occasion to use hydrocyanic acid gas as an insect- 

 icide. The book can be purchased for $1.00 of the publishers, 

 Orange Judd Co., 52 & 54 Lafayette Place, New York City. To 

 those interested in greenhouse fumigation, pages 9-1 1, 118 and 

 124-146 are especially recommended. 



If the cyanide treatment seems undesirable, use a fumigant and a 

 contact insecticide, such as "Nicoticide," manufactured by The To- 

 bacco Warehousing and Trading Co., Louisville, Kentucky, for the 

 fumigant, and Bowker's Tree Soap, manufactured by The Bowker 

 Insecticide Co., Boston, Mass., for the insecticide. 



For each 2000 cubic feet of space, from one to two ounces of 

 Nicoticide should be used according to the lightness of the house. 

 This treatment should last all night, and the next day the plants 

 should be syringed with a solution of Bowker's Tree Soap at the rate 

 of one ounce in one gallon of water. One such combined treatment 

 should be sufficient for several weeks. If a second treatment is 

 desirable, fumigate the same as before, one week later, and spray as 

 before two weeks after the first treatment. 



