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extraction of toxins, for the manufacture of insecticides, from Derris, 
Barbasco and Timbo roots, such, for example",! as Lone ho carpus nicou , 
Derris ell iptica , D. c hinensis , D. malaccensis , and other roots con- 
taining rotehone. 
Wotherspotn. (477), in United States patent 2,058,200, issued 
October 20, 1936, applied for September i'2, 1932, assigned to Derris, 
Inc., claims a composition of matter consisting of a. nonaqueous solu- 
tion of the insecticidal principles obtainable from one or more members 
of the group consisting of derris and pyrethrum in at least one member 
of the group of alkylated phenolic ethers consisting of safrol, anethol, 
methyl eugenol and camphor oil, said solvents being in sufficient 
quantities to maintain the insecticidal principles . in solution. Solvents 
previously used to extract derris and cube include, benzene, acetone, 
acetone-alcohol mixture, petroleum distillate, chloroform, ethylene 
dichloride, ether, toluol, xylene, etc, ." Solvents less effective than 
safrol, etc, include oil of turpentine, pine oil, terpineol, dipentene, 
phellandrene, terpinolene, limonene, cedrene, and petroleum distillates. 
The new solvent extracts of derris or cube may also be used in conjunction 
with water, provided a proper colloid is present to form a' stable emulsion, 
These colloids are soap, starch, gum acacia, gum ghatti, gum karaya, gum 
tragacanth, dextrin, glucose, sucrose, saponin or extracts of plants rich 
in the latter. 
Sankowsky (355), in United States patent 2,058,832, issued October 
27, 1936; applied for March 17, 1933, assigned to Stanco, Inc., claims 
a method for preparing a clear concentrated liquid insecticide which 
comprises extracting rotenone, and other constituents toxic to insects, 
from a plant containing such toxic substances, by treating said plant 
with a mixed solvent, which is capable of selectively dissolving said 
toxic substances to the exclusion of resinous materials which, upon 
dilution of the extract with kerosene, would be precipitated, comprising 
a petroleum distillate having a maximum boiling point below 625° F. and 
a sufficient amount of an organic solvent, soluble in the petroleum 
distillate and having solvent power for said toxic substances to dissolve 
at least 2.5 'percent of said toxic substances. 
Derris root, cube root, or other plants containing rotenone are 
extracted by a counter-flow method, or by percolation, etc., with about 
20 to 30 percent solution of ethylene dichloride in a petroleum distil- 
late. A concentrated extract is obtained containing about 2.5 percent 
of rotenone and about 5 percent of rotenoids. This concentrated extract, 
after being clarified if turbid by the addition of a small amount of 
ethylene dichloride or other similar solvent (e, g. , p-dichlorobenzene 
is mentioned) may be used for the preparation of insecticidal solutions 
by diluting with a petroleum distillate to the strength desired without 
the formation of a residue, or it may be first mixed with a concentrated 
solution of other insecticides and then diluted to the desired strength. 
The petroleum distillate preferably used is one having a maximum boiling 
point below 625° F. The term rotenoids is applied to the insecticidal 
constituents of Derris, Lonchocarpus and Tephrosla. other than rotenone. 
Other solvents that may be used nixed with a petroleum distillate to 
extract rotenone and rotenoids from derris root, cube root or 
