300 INSECTICIDAL MATERIALS AND PRACTICES 



3. Dust iiiul snuff. Snuff may be blown lightly on plants, as 

 house-plants, for lice. 



4. Fumes. Burn dampened tobacco-stems. See Fumigation, 

 p. 287. 



5. Xicotyl. Steep tobacco-stems in water, and evaporate the 

 water. 



6. Tea, or common decoction. Boil the stems or dust thoroughly, 

 and strain. Then adtl cold w^ater until the decoction contains 

 2 gallons of liquid to 1 pound of tobacco. 



There are various concentrated commercial preparations of 

 tobacco which have recently been giving good results against plant- 

 lice. 



White arsenic. — See Arsenicals, p. 291. 



White hellebore. — A light brown powder made from the roots of the 

 white hellebore plant ( Veratrum album), one of the lily family. 

 It is applied both dry and in water. In the dry state, it is usually 

 applied without dilution, although the addition of a little flour 

 will render it more adhesive. In water, 4 ounces of the poison is 

 mixed with 2 or 3 gallons ; and an ounce of glue, or thin flour 

 paste, is sometimes added to make it adhere. A decoction is 

 made by using boiling water in the same proportions. Hellebore 

 soon loses its strength, and a fresh article should always be de- 

 manded. It is much less poisonous than the arsenicals, and 

 should be used in place of them upon ripening fruit. Used for 

 various leaf-eating insects, particularly for the currant-worm and 

 rose-slug. 



