ORCHARD PLANT LICE AND THEIR REMEDIES 
^5 
the oil is rather cold, it lowers the temperature so much that a good emul¬ 
sion is not obtained. In this case the dish may be placed back over the 
fire and the mixture heated to the boiling point when it must be again re¬ 
moved and agitated to form the emulsion. In case the mixture of soapy 
water and kerosene is placed over the fire, it must be watched every moment 
to see that it does not quickly boil over and take fire. As soon as emulsified, 
add twenty-seven gallons of water and use at once. This will make thirty 
gallons of the mixture, and such an emulsion will be one-fifteenth oil (or a 
7% emulsion). This is the strength ordinarily used for the destruction of 
insects upon plants. For larger or smaller quantities, prepare in the same 
proportions. 
Sometimes the emulsion is not perfect and a little oil rises to the top. 
In.such cases,'if the last in the barrel or tank is pumped out upon the foliage, 
it is likely to burn it. So it is advisable, unless the emulsion is of good 
quality, to throw out the last few gallons making no use of it. 
It is best to dilute and apply kerosene emulsion as soon as it is pre¬ 
pared. 
Avoid using alkali or any hard water in making the emulsion, as it will 
cause the oil to separate and rise to the top. Any clean soft water will 
.usually give good results. 
If a stronger emulsion is to be used, prepare as above, but do not use 
much water in making the dilution. For example, if 17 gallons of watei 
were added in place of 27 to dilute the emulsion, it would be one-tenth 
oil or a ten per cent, emulsion, and if 37 gallons were added, it would be a 
five per cent, emulsion. 
Those who have trouble in making kerosene emulsion can procure a 
commercial article known as “Aphiscide” manufactured at Grand Junction, 
or else use one of the tobacco preparations instead. 
Tobacco Decoction — 
Tobacco stems or tobacco dust two pounds. 
Water four gallons. 
Put the tobacco in the water, enought to cover, which may be either cold 
or hot. Place over the fire and when the water has reached the boiling 
point, remove some of the fire and allow the water to simply simmer for 
fully one hour, when the liquid is ready to be drained off, diluted to the 
above proportions and applied.* • 
If whole-leaf tobacco is used, prepare as above using one pound of to¬ 
bacco to each four gallons of water. 
No lime or other alkaline substances should be added to the tobacco 
while cooking. Apply at once, or within a few days after making if pos¬ 
sible. 
Black Leaf —There is nothing to do in the preparation of Black 
Leaf except to thoroughly stir the contents of the can before pouring out 
any quantity for dilution. In most cases one gallon of the Black Leaf will 
be found sufficient for each seventy gallons of water. But if in the treat¬ 
ment of any louse this does not seem sufficient it may be used in proportion 
*Dr. W. P. Headden, Chemist of the Experiment Station, has proven 
that the nicotine is rapMly driven off by boiling, and especially where the 
water is strongly alkaline. 
