ECONOMIC ENTOMOLOGY. 75 



CHAPTER VIII. 



Kerosene Emulsions. 



This remedy has become so popular of late years that 

 it is certainly deserving of a special chapter. 



It stands at the head of the Economic Entomologist's 

 list of insecticides. 



The methods of emulsifying kerosene were first made 

 public in 1880, and since that time they have come into 

 universal use. 



" It cannot be too strongly impressed upon all who use 

 kerosene as an insecticide," says Riley, "that it can be con- 

 sidered a safe remedy only when properly emulsified." 



The great point to be looked after is that there is 

 sufficient agitation to make a permanent emulsion. 



The following formula of Riley's is that which Mr. 

 Hubbard found so satisfactory in destroying the scale- 

 insects infesting the orange : — 



Kerosene 2 gallons = 67 per cent. 



Common or whale oil soap --3^ pound ) 



tit x i ii~~ t = 33 per cent. 



Water 1 gallon \ 



" Heat the solution of soap and add it boiling hot to the 

 kerosene. Churn the mixture by means of a force-pump 

 and a spray-nozzle, for five or ten minutes. The emulsion, 

 if perfect, forms a cream, which thickens on cooling, and 

 should adhere without oiliness to the surface of glass. 

 Dilute before using, one part of the emulsion with nine 

 parts of water. The above formula gives three gallons of 

 emulsion, and makes, when diluted, thirty gallons of wash 



