rfisecticides — Liquid and Dry. 205 



Insecticides in liquid solution are used by spray- 

 ing or syringing the foliage. Either Syringes, Force 



spraying the Plants. 



Pumps, or Garden Engines may be brought into service 

 according to the scale on which the operation is to be 

 carried out. 



But there are drawbacks and difficulties in the use 

 of liquid solutions : one is that the poison does not 

 actually dissolve in the water, which has to be con- 

 stantly agitated to maintain a mixture. Another is the 

 great weight of the quantity required to be used. Dry 

 mixtures are therefore employed, being dusted over 

 the plants. They should be put on preferably when 

 the foliage is still damp after a rain or dew. 



A capital implement for applying dry mixtures to 

 field crops is that shown in the following illustration. 

 It is called the "Farmer's Favorite Duster.'' In oper- 

 atinoj this device, the left hand is held firm while the 



