92 DISEASES 



3 lb. common washing soda, and 10 lb. whale-oil soap ; 

 make the resin and soda into 4 gallons of resin compound 

 stock solution as previously suggested. Mix the whale- 

 oil soap with 5 gallons of boiling water, and while this 

 mixture is still hot add the resin-compound stock solution. 

 Previous to application add 4 gallons of soft water to 

 every gallon of the mixture of whale-oil soap and resin. 



Leaf-eating Insects. — Applications of the " contact 

 poisons " will often destroy many leaf -eating insects, but 

 better results are obtained by poisoning their food. 



This can be done by spraying affected plants with 

 arsenical and other solutions, which may be termed 

 " stomach poisons." Since sucking insects obtain their 

 food from the interior tissues these will be unaffected 

 by such insecticides. 



The following "stomach poisons" will be generally 

 found to give satisfactory results : 



Paris Green. — This may be effectively applied either 

 in powder form or in solution. When it is applied in the 

 dry state it should be first mixed with about twice its 

 weight of starch, flour, or lime. 



To make Paris Green solution, mix at the rate of J lb. 

 Paris Green and 1 lb. powdered lime to every 100 gallons 

 of water. 



London Puiple. — This likewise may be applied dry or 

 in solution. It should be prepared with lime, flour, or 

 starch, in a similar manner and in the same proportions 

 as suggested for Paris Green. 



