286 INSECTS INJURIOUS TO STAPLE CROPS. 



London Purple. 



Used in the same proportions as Paris green, but is 

 much more caustic, its comj)Osition being variable, and 

 should therefore have considerable more lime added. 



Green Arsenoid. 



" Is slightly superior to Paris green in composition and 

 a])pears to be equally safe on foliage when applied at the 

 ordinary strength. The powder is about a tliird lighter 

 than Paris green, and remains correspondingly longer in 

 suspension. ^^ Sold by manufacturers, Adler Color and 

 Chemical "Works, New York, at 15 cents per pound, or 

 13 cents in 100-pound kegs. Rather j^referable to Paris 

 green. Add plenty of lime. 



Arsenite of Lead. 



Least caustic of all the arsenites in its effect upon 

 foliage. Remains in suspension and adheres to foliage 

 better than Paris green. Is white in color. Sells at 15 

 to 18 cents per pound. Manufactured by Wm. II. Swift 

 & Co., Boston, Mass. Can be made ''by combining 

 approximately 3 parts of the arsenite of soda with 7 parts 

 of the acetate of lead (white sugar of lead) in water. 

 These substances when pulverized unite readily and form 

 a white precipitate, which is more easily kept suspended 

 in water than any of the other poisons. At wholesale 

 acetate of lead costs about 7^ cents a pound, and the 

 arsenite of soda, 5 cents. May be used at any strength 

 from 3 to 15 pounds to 100 gallons of water without injury 

 to foliage, and is much safer on delicate plants than any 

 other arsenical." 



" Disparene," manufactured by the Bowker Chemical 



