July 1, 1925 
Colloidal Clays as Emulsifiers for Mineral Oils 
65 
until the emulsion becomes thick, when it may be pumped into stor¬ 
age barrels. A good emulsion looks much like a firm mayonnaise 
salad dressing. 
This emulsion has been made many times in 50-gallon and several 
times in 150-gallon lots by running the mixture twice through the 
pump of a power spraying outfit. 
SUMMARY 
Kaolin, fuller’s earth, and other colloidal clays may be used in 
lieu of soap in making emulsions of mineral lubricating oils for spray¬ 
ing citrus trees. These emulsions are about as effective against 
insect pests as are the soap emulsions r and no more likely to cause 
spray burn. The main value, perhaps, in these clay emulsions is 
that they will mix with any water or desired spray combination 
without special treatment, are easily made, keep indefinitely, and 
cost much less than soap emulsion, both for material and for labor. 
The kaolin used for the emulsion should not cost more than from 
one-sixth to one-ninth as much as the soap, and fuller’s earth is 
cheaper than kaolin. The principal objection to these emulsions is 
that they are a semipaste rather than a fluid. 
59836—25f-5 
