New York Agricultural Experiment Station. 341 



a creamy mass that becomes thick when cool and from which the 

 oil does not separate. For summer use dilute with 15 to 20 parts 

 of water for plant lice and soft-bodied insects ; for plant bugs, larvae 

 and beetles dilute i part with 7 to 9 parts of water. Some venture 

 to use it as strong as i to 5. 



When used as a winter treatment it may be applied as strong as 

 one part of the mixture to four parts of water. After the stock 

 emulsion becomes cold it hardens so that it is necessary to melt it 

 before it can be successfully diluted. It takes fire very readily, so 

 it is always best to have the fire out of doors when making the 

 emulsion. 



Do not apply the mixture with pumps that have rubber balls for 

 valves. Replace the balls with marbles as the kerosene soon destroys 

 rubber. There is a large amount of whale oil soap of poor quality 

 on the market which accounts for trouble that some people experience 

 in forming the emulsion. Only the better grades of whale oil soap 

 should be used. 



CRUDE petroleum AND KEROSENE. 



Crude petroleum and kerosene may be applied clear or emulsified 

 at the rate of 40 per ct. oil and 60 per ct. water. They are con- 

 venient but dangerous sprays and should be used only by experienced 

 sprayers. They may be applied to apple, pear and plum trees but 

 not to peach trees. Experiments with them are recorded in Bulletins 

 194, 202 and 213 of this Station. 



HYDROCYANIC ACID GAS. 



Fused cyanide of potassium ^ i ounce. 



Sulphuric acid : i ounce. 



Water 3 ounces. 



This gas must be confined in a gas-tight room or other receptacle, 

 both to secure efficiency against insects and to prevent injury to 

 other forms of life. It is exceedingly poisonous. 



Pour the water into a glass or glazed earthenware dish and add 



