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to determine by actual measurement whether the percentage of oil and 
water is being properly maintained. 
Kerosene emulsion—Soap formula— 
SE Tae ee et AA Le eee ee Sod eee gallons.. 2 
Whale-oil soap (or 1 quart soft soap)....-.-..-------------- pound.. 3 
Werte 2 sy Sec ae Bs Ae eg ese ee ee mee Ss oe ee gallon.. 1 
The soap, first finely divided, is dissolved in the water by boiling 
and immediately added boiling hot, away from the fire, to the kerosene. 
The whole mixture is then agitated violently while hot by being pumped 
back upon itself with a force pump and direct discharge nozzle throw- 
ing astrong stream, preferably one-eighth inch indiameter. After from 
three to five minutes’ pumping the emulsion should be perfect, and the 
mixture will have increased from one-third to one-half in bulk and 
assumed the consistency of cream. Well made, the emulsion will keep 
indefinitely, and should be diluted only as wanted for use. 
For the treatment of large orchards or in municipal work requiring 
large quantities of the emulsion, it will be advisable to manufacture it 
with the aid of a steam or gasoline engine, as has been very successfully 
and economically done in several instances, all the work of heating, 
churning, etc., being accomplished by this means. 
The use of whale-oil soap, especially if the emulsion is to be kept for 
any length of time, is strongly recommended, not only because the soap 
possesses considerable insecticide value itself, but because the emul- 
sion made with it is more permanent, and does not lose its creamy con- 
sistency, and is always easily diluted, whereas with most of the other 
common soaps the mixture becomes cheesy after a few days and needs 
reheating to mix with water. Soft soap answers very well, and 1 quart 
of it may be taken in lieu of the hard soaps. 
In limestone regions, or where the water is very hard, some of the 
soap will combine with the lime or magnesia in the water and more or 
less of the oil will be freed, especially when the emulsion is diluted. 
Before use, such water should be broken with lye, or rain water 
employed; but better than either, follow the milk emulsion formula, 
with which the character of the water, whether hard or soft, does not 
affect the result. 
The distillate emulsion.—This wash was originated by Mr. F. Kahles, 
of Santa Barbara, Cal. It has been recommended by the California 
State Board of Horticulture and has found very general use in the 
citrus sections of the State. It is substantially an emulsion of crude 
petroleum made in the same way as the kerosene emulsion described 
above, except that a greater amount of soap and only half as much oil 
proportionately is used. The lessened quantity of oil enables it to be 
made comparatively cheaply, and in spite of this reduction in the oil, 
the wash is, if anything, stronger than kerosene emulsion, judging 
from the experience of the writer with both these washes in southern 
California, 
