60 
Journal of Agricultural Research 
Vol. XXXI, No. 1 
sion breaks down, resulting in total loss, because it can not be re¬ 
emulsified. Except for these defects the soap emulsions have given 
great satisfaction. 
In the search for a nonfermentable stabilizer for soap emulsion 
experiments were made with a number of inorganic materials, includ¬ 
ing kaolin, a china clay composed mostly of hydrous aluminum 
silicate, which did not prove satisfactory for this purpose. Follow¬ 
ing suggestions of the junior author, these experiments led to the 
use of it as an emulsifier instead of soap. 
KAOLIN AS AN EMULSIFIER 
The first attempt by the writers to use the kaolin as an emulsifier 
resulted in obtaining a perfect emulsion, and thereafter practically all 
the experimental work was directed to determining the quantity of 
kaolin required for best results. Oils having the same physical speci¬ 
fications as those previously given were used in all the kaolin emulsion 
experiments. 
The following formulae were tried in preparing the first few lots of 
kaolin emulsion: 
Mineral 
lubricating 
oil 
Water 
Kaolin 
Odilons 
Gallon 
Pounds 
A 
2 
1 
4 
B 
2 
1 
2% 
C 
2 
1 
2 
Procedure. —Milk of kaolin was made by simply adding the water 
to the kaolin and permitting the mixture to stand 15 to 30 minutes. 
The oil was then added to this mixture and emulsified without the aid 
of heat by passing the materials twice through a bucket pump. 
All of the above formulae produced reasonably satisfactory emul¬ 
sions. The first test, where 4 pounds of kaolin were used, produced 
a perfect emulsion, but the resulting paste was entirely too stiff for 
practical grove spraying. Where only 2 pounds were used, the emul¬ 
sion tested satisfactorily when diluted with water, but there appeared 
to be some free oil in the emulsion itself, and it was thought advisable 
to use a little more kaolin. The formula whereby 2 % pounds were 
used, or 1pounds per gallon of oil, proved to be perhaps the most 
satisfactory, and it was used in practically all extensive sprajdng work. 
Attempts were made to produce an emulsion by only stirring, in 
much the same manner as in preparing the cold-stirred soap emulsions. 
The oil was added very slowly and gradually to the milk of kaolin, but 
the writers were not able to stir it violently enough to produce a satis¬ 
factory emulsion. No doubt an emulsion can be made by this method 
if sufficient stirring is given the mixture and the oil is added very 
gradually. 
FULLER'S EARTH AS AN EMULSIFIER 
Fuller’s earth, a crude material of variable composition, but mostly 
of hydrous aluminum silicate, used extensively in the textile and oil 
industries, was tested for its value as an emulsifying agent for mineral 
oils. Experiments were conducted to determine whether it is a satis¬ 
factory material for emulsifying mineral oil, the following formula 
being used: 
