Colorado Experiment Station 
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ing is not necessary. Stir briskly for about twenty minutes after the 
last of the oil has been added.” 
Use: 
Soap . 1 pound 
Water . 6 to 10 gallons 
10 . Kerosene Emulsion 
Soap (whale-oil or common so&p) . H pound 
Water . 1 gallon 
Kerosene . 2 gallons 
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Dissolve the soap in the water by boiling. Remove from the fire, 
and while still hot mix with the kerosene. Agitate vigorously by driv¬ 
ing it through a spray pump until the oil is well emulsified and a uni¬ 
form cream'-colored mixture is produced. Small amounts may be 
emulsified by stirring vigorously, or by using a rotary egg-beater. 
Dilute this stock solution by using one part to lo or 12 parts water 
for a summer spray. For use on dormant trees, use one gallon of the 
stock solution to 5 to 7 gallons of water. 
The strength of an oil emulsion depends upon the percent of oil 
it carries. The strength of the emulsion to use is often indicated by 
this percentage. 
To obtain the amount of dilution to secure a certain percent di¬ 
vide the percent of kerosene in the stock solution by the percent de¬ 
sired in the diluted emulsion and the result will be the amount to which 
one gallon should be diluted. As one gallon of the stock solution made 
according to the above formula will carry sixty-six and two-thirds 
percent of kerosene, to obtain the amount to which it should be diluted 
to get a 1234 percent emulsion, divide 662-3 12^2, which gives 
5 1-3. One gallon diluted to make 5 1-3 gallons will give a 12^ per¬ 
cent emulsion. 
Summer sprays should carry from 5 to 7 percent kerosene, and 
spravs for dormant trees from 10 to 15 percent. 
II. Kerosene and Crude Petroleum 
These oils are sometimes used pure as insecticides. Some years 
ago they were used quite extensively in parts of the East in, -[.ecu 
spraying machinery that diluted them with water as they were being 
applied to the trees. Other sprays equally effective and much safer 
to use on trees have taken their places. Many growers use them in 
painting or swabing the clusters of woolly aphis that gather about 
wounds on apple trees. 
12. Soluble or Miscible Oils 
There are several concentrated oil emulsions on the market known 
as soluble or miscible oils. These are used almost entirely as dormant 
