16 horticulturist's rule-book. 



Tobacco. — 1. Stems, placed on the walks and under the 

 benches of greenhouses, for plant-lice. Renew it every 

 month. 



2. Tobacco- water, used with whale-oil soap. 



3. Dust. See Snuff. 



4. Fumes. Burn dampened tobacco-stems. See Fumi- 

 gation. 



5. Nicotyl. Steep tobacco-stems in water and evaporate 

 the water, 



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

 thoroughly and strain. Then add cold water until the 

 decoction contains 2 gallons of liquid to 1 pound of tobacco. 



There are various commercial preparations of tobacco 

 for use in greenhouses. 



Whale-oil soap. — 1 pound whale-oil soap to 6 gallons of 

 water. For mealy-bugs and similar insects. It will injure 

 some tender plants. 



White arsenic. — See Arsenic. 



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, 1 ounce of the poison is mixed with 3 

 gallons ; and an ounce of glue, or thin flour paste, is some- 

 times 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 

 demanded. It is much less poisonous than the arsenites, 

 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. 



