20 
It is termed distillate spray, because the oil used is a crude distil- 
late of the heavy California petroleum. The product used for pre- 
paring the emulsion should have a gravity of about 28° Baumé, and is 
the crude oil minus the lighter oil, or what distills over at a tempera- 
ture between 250° and 350° C. In general characteristics it is very 
similar to lubricating oil. The emulsion, or, as it is genereally known, 
‘‘cream,” is prepared as follows: Five gallons of 28° gravity distillate; 
5 gallons of water, boiling; 1 to 13 pounds of whale-oil soap. The 
soap is dissolved in hot water, the distillate added, and the whole 
thoroughly emulsified by means of a power pump until a rather heavy, 
yellowish, creamy emulsion is produced. The product is very similar 
to, but rather darker in color than the ordinary kerosene emulsion. 
For use on citrus trees it is diluted with from twelve to fifteen parts 
of water, the stronger wash for the lemon and the weaker for the 
orange. The ‘‘distillate cream” is commonly prepared and sold by 
oil companies or individuals at from 10 to 12 cents a gallon, making 
the diluted mixture cost in the neighborhood of a cent a gallon. 
In using both of the above emulsions, it is advisable to first break 
the water by the addition of a little lye, a fourth-pound of lye being 
ample for 50 gallons of water. 
Kerosene emulsion (milk formula)— 
Kierosen eed sere Se he eee else ea ee ee eae eee gallons.. 2 
ilk (aour) eee hh s se ae ee eee gallon.. 1 
Heating is unnecessary in making the milk emulsion, which other- 
wise is churned as in the former case. The change from a watery 
liquid to a thick buttery consistency, much thicker than with the soap, 
takes place very suddenly after three to five minutes’ agitation. With 
sweet milk difficulty will frequently be experienced, and if the emulsion 
does not result in five minutes, the addition of a little vinegar will 
induce prompt action. It is better to prepare the milk emulsion from 
time to time for immediate use, unless it can be stored in quantity in 
air-tight jars, otherwise it will ferment and spoil after a week or two. 
How to use the emulsions.—During the growing period of summer, 
for most plant-lice and other soft-bodied insects, dilute the emulsion 
with from 15 to 20 parts of water; for the red spider and other plant 
mites the same, with the addition of 1 ounce of flowers of sulphur to 
the gallon; for scale insects, the larger plant-bugs, larvee, and beetles, 
dilute with from 7 to 9 parts of water; apply with spray pump. 
For winter applications to the trunks and larger limbs of trees in 
the dormant and leafless condition, to destroy scale insects stronger 
mixtures may be used, even to the pure emulsion, which latter can not 
be sprayed successfully, but may be applied with brush or sponge. 
Diluted with one or more parts of water it may be applied in spray 
without difficulty. The use of the pure emulsion is heroic treatment 
and only advisable in cases of excessive infestation, and in general it 
is much better and safer to defer the treatment until the young scales 
