GREENHOUSE AND COLD FRAME FUMIGATION 145 



Leave exposed twenty to thirty minutes, and no 

 longer. Do the work on a dark, cloudy day, or late 

 in the evening, or at night. Thoroughly air the 

 frames afterward, and empty the residue in the jars. 

 Do not inhale the gas, and do not handle the cyanide 

 carelessly. Both are deadly poison if breathed or 

 swallowed. 



General summary. (i) The cubic contents of the 

 house and the amount of cyanide to be used should be 

 carefully determined. (2) The enclosure should be 

 made as nearly gas-tight as possible. (3) The venti- 

 lators should be arranged so as to be opened from the 

 outside. (4) Place the screw-eyes in their proper 

 .places and run the string through them. (5) Deter- 

 mine whether the bag of cyanide is directly over the 

 jar before the chemicals are placed in it. (6) Measure 

 the acid and water carefully, place it in the vessels, 

 hang the bag of cyanide directly over them, and arrange 

 the protection sheets of paper. (7) The bags should 

 be lowered by loosening the string from the outside 

 door. (8) Doors should be properly closed and left 

 locked the desired length of time. (9) After proper 

 exposure open the ventilators and doors from the out- 

 side, and leave them thirty or forty minutes before 

 entering the house. After that time they can be closed 

 and left until morning. (10) The contents of the jars 

 should be buried or thrown upon a manure pile. ( 1 1 ) 

 Jars should be thoroughly washed with cold water and 

 set away for future use. 



A practical application . In reply to a recent letter, 

 Edward A. Moseley, of Washington, D. C., says: "I 

 most certainly believe cyanide fumigation is practical. 



