386 A Practical Hand Book 



oil and churn by forcing through the spray pump, pointing the 

 nozzle back into the mixture, until it becomes thick; then add the 

 rest of the water, and spray. 



It is well to repeat this treatment about ten days later, both 

 because the first treatment may have missed some of the insects 

 and because some of the eggs may not have hatched at the time of 

 the first spraying. 



INSECTICIDES. 

 Arsenate of Lead. 



This is now sold ready for use, by adding the requisite amount of 

 water, by a number of manufacturers. It is probably our most 

 effective stomach poison, for though costing more than paris 

 green, it remains on the plant where it has been sprayed a much 

 longer time, and is less liable to burn the foliage. Unless large 

 quantities are to be used it is better to buy it than to make it, but 

 if directions for making are desired, these will be supplied on appli- 

 cation to the Agricultural Experiment Station of any state. 



Ordinarily about three pounds of arsenate of lead should be 

 mixed with fifty gallons of water to spray, but for the gypsy moth, 

 brown-tail moth and elm-leaf beetle, five pounds should be used 

 instead. In spraying it is necessary that the sediment should be 

 constantly stirred, in order for it to be carried out through the 

 pump and be evenly distributed. 



Paris Green. 



This material is rarely as effective as the last, and is only men- 

 tioned because it may in some cases be difficult to obtain the 

 other. One third of a pound of paris green should be mixed with 

 half a pound of quicklime which has just been slaked in some 

 water, and water should be added to make a total of about fifty 

 gallons, and the whole well stirred while spraying, for the reason 

 stated above. 



