44 VINES 
For this work during the growing season, 
there are various kinds of emulsions, all of which 
are also useful against the soft-bodied, sucking 
insects. Some of these, the miscible oils, are 
already prepared, except for dilution with water. 
These are certainly the most convenient to use 
and are not excessively expensive to buy. Kero- 
sene emulsion may be made at home by dissolving 
one-half pound of soap in one gallon of hot water. 
Remove from the fire and while still hot add two 
gallons of kerosene. Churn the mixture violently, 
or pump it through a sprayer until a creamy, 
emulsified liquid results. For work on dormant 
trees, add five to seven parts of water; for killing 
aphides on open foliage, ten to fifteen parts of 
water. Whale oil soap is practically as useful 
as any of these emulsions, and may be made by 
dissolving a pound of the preparation in five to 
seven gallons of hot water. This is especially 
effective against aphides. For the woolly aphis 
in the greenhouse, the common laundry soap or 
even Ivory will do. 
The use of hydrocyanic acid gas in fumi- 
gating is fully described in Chapter XIX. A 
standard strength, safe to use in any case, 
consists of potassium cyanide, one ounce; sul- 
phuric acid, two ounces; water, four ounces. 
