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•ECONOMIC ENTOMOLOGY 



III. Commercial Wash. — Commercial washes are now sold which 

 are quite reliable. Directions are given as to dilution. Usually they 

 test about 1.290 sp. gr. or 33° Baume. 



Lime-sulphur when used at summer strength acts also as a stomach 

 poison, but more slowly than arsenate of lead. Flour-paste as a 

 "sticker" is often added, especially in summer sprays (8 lb. flour 

 boiled into a thin paste in 8 gal. of water, mixed with 160 gal. 

 of lime-sulphur). 



It is to be noted that Lead Arsenate, not Paris green, is to be used 

 with the Lime-sulphur Wash, When Paris green, a copper-aceto 

 compound, is added to lime-sulphur the copper is attacked and free 

 soluble arsenic is liberated in quantity sufficient to kill foliage. 



IV. Limc-sidphur (Self -boiled). — Prepared by slaking 8 lb. best 

 stone lime in a small quantity of cold water; while slaking 8 lb. of 



