POISON INSECTICIDES 17 



Black death 

 It is composed mostly of gypsum. ^- 



LONDON PURPLE ^^ 



It is a waste product in the manufacture of ani- 

 line dyes ; contains a large percent of soluble arsenic 

 and must have lime added in liberal amounts to pre- 

 vent burning. It is not used to any extent. 



Hellebore ^"^ 



The term ''hellebore" is said to be correctly ap- 

 plied only to Hellehorus niger which grows in Eu- 

 rope and is not now imported commercially. 



It is a whitish poisonous powder obtained from 

 pulverizing the roots of the hellebore plants Vera- 

 triim album and Veratrum viride. The powder of 

 the former is largely imported while that of the 

 latter is an American product. Both seem equally 

 valuable as insecticides. It is apt to lose its 

 strength quickly and often difficult to obtain fresh. 

 Can be applied to ripening fruit without fear of 

 poisoning, because its strength is so rapidly lost in 

 open air. It is valuable for the currant worm and 

 is usually applied dry either pure or mixed with 

 flour or lime at the rate of i to 3 ; may be applied 

 wet by steeping i ounce in a quart of water and 

 adding another quart of cold water. 



Poison baits 



A mixture of fruit juice, bran, and parls green 

 or white arsenic for cutworms, grasshoppers, and 

 army worms has proven very efficient. A recom- 



32 Van Slyke— N. Y. State Expt. Stat., Bull. 165. 



33 IMarlatt— U. S. Dept. Agr., Ear's' Bull. 127, p. 8. 



3* Cook, Hutchison and Scales— U. S. Bu, Ent, Bull 245, p. 17. 



