THE SPRAYING OF PLANTS. 55 



ble in water, but as there is usually present a small amount of 

 soluble arsenic, it is always well to add a little fresh lime to 

 the mixture before applying, that injury to the foliage may be 

 averted. Paris green is generally mixed with water in the pro- 

 portion of I pound to 200 gallons. If lime is added, however, 

 a pound to lOO gallons may be used. 



Kerosene. Kerosene is the specific for all sucking insects. 

 It kills by contact and. owing to its cheapness and efficiency, will 

 probably remain the most valuable insecticide for this class of 

 insects. The form in which it is usually applied is the soap 

 emulsion,* but there are now several forms of spray pumps 

 which make a mechanical mixture of kerosene and water, thus 

 greatly reducing the labor. 



Tobacco. A strong decoction of tobacco ("tobacco tea") is 

 often used with success in destroying the lice upon rose bushes 

 and tender, soft-wooded plants. 



WHAT APPARATUS IS NECESSARY? 



In order that the best results m.ay be obtained, suitable appa- 

 ratus is needed. Such apparatus consists of a good force- 

 pump, with one or two lines of discharge hose, nozzles, a barrel 

 or tank for holding the mixture and a wagon for carrying all. 



The Pump. The pump should be large enough to supply two 

 lines of "discharge pipe, so that one man may pump while two 

 others distribute the spray. The small bucket and knapsack 

 pumps do very well for a limited amount of spraying, but in 

 field work, toys will not answer. All parts of the pump that 

 are subject to wear should be of brass and should be carefully 

 adjusted. 



The Hose. Two pieces of one-half inch hose, of sufficient 

 length to give freedom to the operator are needed. About fif- 

 teen feet is the length usually preferred. 



The Nozde. The nozzle is one of the most important parts 

 of the spraying apparatus. It should throw a fine mist-like 

 spray, and should be easily cleaned. The one in most common 

 use is, perhaps, the Vermorel. The McGowen is one of the best 

 for tall trees. 



* One-half pound hard soap, 1 gallon boiling water, 2 gallons kerosene. Dissolve 

 the soap in the water, add the kerosene and churn through a force pump for ten 

 minutes. For use, dilute ten to twenty times with water. 



