68 



16. Whale-Oil Soap. — Dissolve i lb. of soap in one to two 

 gallons of warm water. 



17. Rosin and Whale-Oil Soap Compound.--- Mix 1 gallon of 

 water with 3 lbs. of powdered washing soda and 4 lbs. of 

 powdered rosin. Boil till dissolved and, while boiling, 

 make up slowly to 5 gallons. 



In a separate vessel boil 10 lbs. of whale oil soap with 5 

 gallons of water. These may be mixed while hot to m ike 

 the stock solution or, when cold, mix these two with 35 

 gallons of cold water, pouring both into the water together 

 while actively stirring the mixture. However mixed, the 

 final amount must be 45 gallons. 



18. Tobacco and Soap. — Dissolve 1 quart of soft soap, or 

 h lb. of hard soap in 5 gallons of water, and add 2 quarts of 

 strong tobacco decoction (No. II.) 



Use of The Poisons 



The poisons enumerated above are to be applied as follows: — 

 Those in list A are suitable for application to plants that are eaten 

 by caterpillars (worms) and other biting insects. The arsenical 

 poisons, such as London Purple or Paris Green, are of universal 

 application against caterpillars and other pests that destroy foli- 

 age, but it must be remembered that arsenic is poisonous to man 

 and does not quickly get entirely washed off by rain. Hellebore, on 

 the other hand, very soon loses its poisonous properties and be- 

 comes harmless after some exposure to air. Pyrethrum is harmless 

 to higher animals, but has a powerful influence on insects. It may 

 be applied without danger of poisoning human beings or cattle. 

 Tobacco has a special value in a few cases only, and has less claim 

 to be regarded as a general insecticide. Those in list B are the 

 contact-poisons for application to plants infested with mealy-bug, 

 scale insects, etc. 



When using large quantities of these insecticides, the question 

 of relative cost becomes important. 



The prices of the materials mentioned in list A are subjoined, 

 as quoted in New York : — 



Paris Green - - - - 25 cents per lb. 

 London Purple - 6-15 cents per lb. 



Hellebore - - 20 cents per lb. 



Pyrethrum - - - 35 cents per lb. 



In Barbados (Messrs. C. F. Harrison & Co.) the following may 

 be obtained : — 



Paris Green - - 54 cents per ib. 



London Purple - 30 cents per lb. 



Refuse Tobacco - 4 cents per lb. 



The cost of washes in list B, has been calculated, per 100 gallons 

 of wash ready for application, exclusive of fuel and labour. These 

 figures are approximate and represent, as closely as possible, firstly, 

 the cost of the materials in large quantities in Barbados, free of 

 dutv and secondly, the cost at retail prices as quoted in Barbados. 



