Materials and Formulas. 153 



cations are still made, but to a limited extent. Most plants 

 are easily injured by the oil. Coleus, grape, peach, pea, and 

 eggplant appear to suffer less than others. Paraffine, a closely 

 related product, may be used at the rate of a wineglassful to 

 a watering-can of water, the mixture being sprayed upon the 

 insects. 



Pure kerosene will destroy trees and branches which are sev- 

 eral years old if a sufficient amount of the oil be applied. The 

 beneficial results of such treatment are open to doubt, and the 

 practice can hardly be advised except in isolated cases, when 

 some unusual danger is feared. Howard has found that the oil 

 may be used to advantage in the destruction of the mosquito. 

 These breed in stagnant water, such as is commonly found 

 in pools, etc., and by the use of 1 ounce of oil to 15 square 

 feet of water surface, a film is formed which is very effectual 

 in destroying all forms of aquatic insect life. 



KEROSENE AND MILK EMULSIONS. By emulsifying kero- 

 sene with some other material a very uniform dilution of the 

 oil may be obtained, and it may be used of any desired strength. 

 Milk has been very extensively used as an emulsifying agent, 

 and it possesses particular value in those regions in which it is 

 difficult to obtain soft water, hard water being unsuited to 

 assist in making emulsion when soap is used instead of milk. 



Kerosene and Condensed Milk Emulsion. 



Kerosene 2 gallons. 



Condensed milk 3 pints. 



Water " 



It is unnecessary to heat the ingredients, but they may be 

 mixed and immediately churned or agitated by means of a 

 force-pump until a perfect emulsion is obtained. 



Kerosene and Sour Milk Emulsion. 



Kerosene 2 gallons. 



Sour milk 1 gallon. 



These liquids should be agitated in the same manner as the 

 preceding. The mixture will soon assume a thick buttery con- 

 sistency, and when the entire mass is in this condition the oil is 

 properly emulsified. The addition of a little vinegar is said to 

 hasten the process, especially if the milk is sweet instead of 



