90 SHADE TIIEES. 



be a pure material in each instance. Anything that rims 15 

 per cent, or over is good, and nearly all the leading brands 

 sold in the State reach that percentage. The dry material 

 runs 30 per cent., and is therefore about twice as strong as 

 the average paste. None of the leading brands have more 

 than a trace of soluble arsenic, and practically it is impos- 

 sible to injure the foliage of any shade tree with any mixture 

 likely to be put on by even an ignorant laborer. 



All the commercial tank sprayers have an agitator which 

 keeps the spraying mixture stirred while pumping, and some- 

 thing of that sort is needed in any case, so as to make sure 

 that the material is uniform throughout the spraying period. 



In all cases the poison should be first mixed up with water 

 in a paii or tub so as to get it into a smooth thin paste. This 

 should be gradually run into the tank while filling, and the 

 agitator should be kept constantly going, so as to get a thor- 

 stir the oughly even poisonous mixture to start with. 



mixture. Then, while a slow settling does begin almost 



immediately, it is very slow and the mixture can be kept 

 in proper shape with very little stirring. It is always better 

 to use up a tank full of mixture completely, as soon as pos- 

 sible after it is made, and it should never be allowed to stand 

 over night. It never stirs up quite as completely next day, 

 and if part of a tank remains unused at the end of a day's 

 work, better take out the plug and let it rim to waste than 

 try to save it for a future day. 



With a proper outfit and a good crew, the next point is to 

 get the material on in such a way as to be most effective. An 

 ideally effective application would be one in 

 thSroigbiy? w T hich every leaf received an even and complete 

 coating of the spray, so that not a particle of 

 the foliage could be eaten by any insect without its receiving 

 at the same time a dose of poison. As we cannot hope for 

 ideally effective work, we must try and get as close to it as 

 possible, remembering always that no one insect eats very 

 much, and that every female specimen that gets a safe meal 

 may lay a batch or two of eggs before getting another, and 

 perhaps fatal, bite. 



