12 farmers' bulletin 880. 



Do not fumigate when the temperature in the greenhouse is below 

 52° or above 70° F. 



Do not leave the chemicals within reach of those unacquainted 

 with their poisonous nature. Always have them properly labeletL 



Do not handle the chemicals any more than is absolutely necessary. 

 It is well to have a pair of old gloves for this, and to use them for 

 no other purpose. Always wash the hands thoroughly after hand- 

 ling the chemicals whether gloves have been used or not. 



Do not allow the acid to splash or drop on the clothmg or skin. 



Do not stay in the greenhouse any longer than is necessary to 

 place the cyanid in the jars, and never enter a greenhouse charged 

 with the gas until it has been thoroughly aired. 



Do not fail to post danger signs at all entrances before setting off 

 the charge, and to see that the greenhouse is closed tightly. 



Do not attempt to fumigate without adjustmg the ventilators so 

 that they can be operated from the outside. 



Do not attempt to fumigate a large greenhouse alone. 



Do not fumigate a greenhouse adjoining a dwelling without notify- 

 ing the occupants before fumigation. 



Do not pour the water on the acid ; pour the acid on the water. 



Do not become negUgent in any of the precautions; to do so may 

 cause serious results. 



GUIDE TO GREENHOUSE FUMIGATION. 



Table II is offered as a guide to those desiring to employ hydro- 

 cyanic-acid gas for controlling greenhouse pests. As indicated in 

 this table, certain insects and plants are more resistant to hydrocyanic- 

 acid gas than are others, and this fact siiould be borne in mind when 

 a greenhouse contaming a miscellaneous collection of plants is to be 

 fumigated. 



