62 PARA RUBBER. 



they come in contact with their bodies. The following are 

 amongst the. most generally used "contact-poisons " : 



Kerosene Emulsion. This is prepared by dissolving hard 

 soap in the proportion of I Ib. to every 2 gallons of boiling water. 

 When thoroughly mixed, and while the water is still hot, 4 gallons 

 of kerosene are slowly added for every pound of soap, and the 

 mixture thoroughly churned with a force pump or syringe until 

 it forms a cream. This is the stock solution, which previous to 

 application should be diluted with 66 gallons of soft water. 



Whale-oil Soap Solution is prepared by mixing whale-oil 

 soap at the rate of | Ib. to every gallon of water (boiling). 



Tobacco Solution is prepared as follows : Steep tobacco leaf 

 at the rate of I Ib. to every gallon of water for twenty-four hours, 

 and afterwards strain through a cloth. Dissolve hard soap at the 

 rate of i Ib. to every 10 gallons of water. Mix the tobacco 

 water and the soap solution at the rate of i gallon of the former 

 to 10 gallons of the latter, and it is ready for use. 



Leaf-eating Insects. Although contact-poisons will often 

 destroy many leaf-eating insects, better results are obtained by 

 poisoning their food. This is done by spraying the leaves of 

 affected plants with arsenical and other solutions, which are 

 termed " Stomach poisons." Since the sucking insects obtain 

 their nourishment from the interior tissues it will be obvious that 

 it is impossible to poison them by this means. 



The following " stomach poisons" will generally be found to 

 give the desired results : 



Paris Green may be effectively applied either as powder or 

 made up into a solution. By the first mentioned method it should 

 be first mixed with twice its weight of starch, flour, or lime. 

 Paris green solution is made by dissolving Paris green with lime 

 at the rate of J Ib. of the former to i Ib. of the latter to every 100 

 gallons of water. 



London Purple may also be applied dry or in solution, and be 

 prepared with lime, flour, or starch in a similar way and in like 

 proportions to that suggested for Paris green. 



Boring Insects. Boring injuries to plants may either be 

 caused by the " perfect insect," as in the case of some Longicorn 

 beetles, or by their larvae. Many beetles attack only dead stumps 

 and debilitated trees. The remedy to apply in such cases has 

 already been dealt with. 



