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rotenone or the like are particularly efficient, "but the 
high price of these drugs has proven to he prohibitive as 
regards their use on a large scale." 
Hamilton (L84), in U. S. patent 2,030,584, issued February 11, 1936, 
applied for June 5, 1934, claims an insecticide including water, a 
suitable oil and finely powdered natural parts of a plant selected from 
the group consisting of derris and cube root containing an inherent 
emulsifier and properties toxic to insects. Reference is made to the 
use of acetone, alcohol, ether and ethylene dichlorides as solvents for 
the active principles of derris and cube. To prepare the paste, 3 or 4 
parts of finely powdered derris or cube root av-o added to 8 parts of 
water and 8 parts of oil, either mineral, vegetable or animal, and the 
mixture emulsified in a suitable machine. In case the derris is reduced 
to 1 part it is necessary to add 2/3 to 1 part colloidal clay (wilkeite, 
bentonite, etc.) to make a physically stable emulsion. A preservative 
such as l/2 to 1 percent carbolic acid may be added; a sodium, potassium 
or an ethanolamine soap may be used instead of the clay, and an anti- 
oxidant such as tannic acid may also be added. 
The paste emulsion insecticide produced as aforesaid, makes a 
quick breaking emulsion when diluted with water for spraying. Insecticide 
sprays of this invention possess from 15 to 20 percent greater toxicity to 
plant lice than sprays of the same high dilution made from derris and cube 
insecticides of the chemically extracted kind, 
Buc (56), of the Standard Oil Development Co., in U. S. patent 
2,042,296, issued May 26, 1936, applied for March 12, 1931, uses an aryl 
alkyl ether to keep rotenone and rotenoids from derris or cube in solution 
in kerosene. 
An example of the invention is 0.5 percent rotenone, 5 percent 
secondary hexyl cresyl ether, 94.5 percent petroleum oil having a gravity 
of 2?o A.P.I, and a viscosity of 115 Saybolt at 100° I. Buc states that 
he has- prepared a stable kerosene solution containing 0.25 percent of 
rotenone with only 0.75 percent of secondary hexyl phenyl ether as mutual 
solvent. 
Wotherspoon (476), in United States patent 2,052,374, issued 
August 25, 1935, applied for April 28, 1934, claims an aqueous disseminatable* 
composition of matter consisting of an insecticide obtainable from derris 
and similar insecticidal-containing plant materials containing rotenone, 
deguelin, tephrosin and toxicarol and a water-soluble phenol containing 
at least two hydroxyl groups. 
"I have found that if rotenone, dihydrorotenone, 
finely ground derris or cube, solid extracts of derris 
or cube, the hydrogenated derivatives of same, either 
alone or in mixtures, are melted or intimately mixed with a 
solid water-soluble phenol containing two or more nydroxyl 
groups, the resulting product after cooling and grinding 
is soluble, or miscible, with water in any proportions. 
