SPRAYING FOR INSECTS AND FUNGI. 149 



for this numerous family are whale-oil soap, kerosene 

 emulsion, and infusions of and powdered tobacco. But the 

 standard solution that can be used profitably on all types 

 of the sucking insects is kerosene emulsion. Kerosene 

 has been used for many years in a pure state by carefully 

 applying it to the insects or wiping them from the leaves 

 and stems with a cloth moistened with kerosene. The 

 next move was to mix it with water for spraying. But 

 not until soap or oil was added to the solution could a 

 perfect mixture of the oil and water be effected. It is 

 said that dealers in kerosene, when it commanded a higher 

 price than at present, first made the discovery that oil and 

 soft water would mix when a solution of soap was added. 

 The use of the kerosene enmlsion was quite common, when 

 the writer visited west and east Europe in 1882, for the 

 destruction of the several species of aphis in greenhouses, 

 and at Proskau in north Silesia it was used for the bark 

 and leaf lice of the orchard fruits. In this country the 

 first one to use it known to the writer was Professor Cook, 

 then professor of entomology at the Agricultural College of 

 Michigan. During a visit to the Michigan station in 1878 

 the writer was shown the beneficial effects of spraying for 

 sucking insects with a mixture of kerosene and soapy 

 water. 



The usual formula for making kerosene emulsion is to 

 shave one half pound of ivory soap or whale-oil soap in 

 one gallon of soft water and boil until dissolved. The 

 kettle is removed from the stove and while boiling hot two 

 gallons of kerosene are added that has been previously 

 warmed in the sun or in a warm room. The mixture is 

 then agitated by active stirring for ten minutes. If not 

 very hot the mixing is often effected by forcing it through 

 the sprayer back to the vessel until it is creamy in color 

 and will flow evenly down the sides of the pail or tub. 



