USEFUL IXSECTICIDES 617 



exposure to the air. In temperate countries it is generally used 

 in conjunction with potash as a spray fluid on dormant trees and 

 bushes, when, in addition to cleansing the trees, it proves 

 destructive to many forms of insect life. The solution is made 

 as follows: Caustic soda, 1 lb.; soft soap, i lb.; carbonate of 

 potash, 1 lb; water, 10 gallons. Dissolve the soft soap in hot 

 water, and add to cask or vessel containing 10 gallons of water 

 in which the soda and potash have been dissolved. 



Emulsions. Kerosene, paraffin, petroleum, etc., in the form 

 of emulsion afford one of the most effective insecticides known 

 for sucking-insects. Many formulas have been devised, but the 

 following will serve all practical purposes: Kerosene (paraffin or 

 petroleum), 1 gallon; soft soap, 1 lb.; boiling water, 1 gallon. 

 Dissolve soap in boiling water, and add, boiling hot, to the 

 kerosene. Churn the mixture thoroughly until a cream-like 

 emulsion is formed. This should thicken to a jelly on cooling, 

 and adhere without oiliness to the surface of glass. The hotter 

 the mixture, the easier the emulsion is formed. For use, add 

 1 part emulsion to 10 parts water. No form of emulsion should be 

 applied to foliage during sunshine. 



Gondal-fluid. 1^ oz. gum, 8 oz. asafoetida, 8 oz. bazaar aloes, 

 3 oz. castor-cake. Mix well with water, add clay to thicken, and 

 paint on the base of trees which are liable to be attacked by 

 white-ants or other insects. Gondal fluid is an Indian pre- 

 paration and has been specially recommended by SIR GEORGE 

 WATT for applying to Tea bushes as a preventive against white-ants. 



Hot water as an insecticide. Up to a temperature of 170 or 

 200 degrees (Fah.) of heat, hot water will destroy many de- 

 structive insects without injuring their host plants. Even boiling 

 water applied by a syringe will usually cool sufficiently between 

 the syringe and plant to avoid injury to the latter, while it is still 

 hot enough to kill the insects. 



London Purple. A fine powder arsenical preparation, of 

 similar use to " Paris Green," but generally considered to be less 

 safe than the latter. It is a by-product obtained in the manu- 

 facture of aniline dyes. 



Paris Green. Also known as "Emerald Green," "Mitis Green," 

 and "French Green." A powerful irritant and poisonous com- 

 pound of arsenic, copper and sulphuric acid, which has the 

 appearance of fine po\vder with a clear green colour. For use take 

 one ounce of the powder and mix in 12 gallons of water. Like 



