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yellow condensate is obtained, giving the reactions of rotenore and 
containing substantially all the active material present in the original 
root . 
Other carrier liquids such as Apiexon, heavy mineral oil, cotton- 
seed oil, olive oil, etc., nay "be used when it is desired to obtain a 
solution of the active ingredients as distillate, the dry powdered derris or 
cube root nay be r.ixed with a carrier liquid which is either wholly dis- 
tillable at the temperatures and pressures employed , or comprises a portion 
so distillable. Thus a mixture of the oils known respectively under the 
trade names "Apiczon A" and "Apiezon K" may bo used. The active ingredients 
distil over together with the "Apiezon A" leaving behind a suspension or 
solution of the residue in the "Apiezon K." The distillate, which is a more 
or less concentrated solution of the rotenone etc. in "Apiezon A" (the 
concentration can be varied by varying the proportion of "Apiezon A" taken), 
is suitable for dilution with kerosene or other volatile mineral oil for 
use as insecticidal spray. 
Imperial Chemical Industries, Ltd., assignee of Fawcett (214), in 
Canadian patent 369,499, issued October 26, 1937; applied for October 28, 
1935; claims the process for the production of rotenone preparations 
which comprises subjecting a natural rotenone-containing substance to 
distillation without ebullition at a pressure of 10 -2 to 10"^ mm. of 
mercury under such conditions that the evaporating and condensing surfaces 
are substantially co-extensive and are in close proximity to one other, and 
collecting the distillate. The material may be dried and ground and mixed 
with a carrier liquid which is substantially volatile at the temperature 
and pressure to be employed. This is similar to British patent 446,576, 
French patent 797,052, and United States patent 2,096,678. 
Eichhorn (125), in German patent 630,433, issxied May 26, 1936, 
applied for November 22, 1932, extracts powdered derris (or c\ibe) powder 
at 40 to 50° C. with an equal quantity of a dilute (10 percent) solution 
of sodium bisulphite, then neutralizes and concentrates in vacuo. 
Chromek (80), in German patent 643,804, issued April 17, 1937, 
applied for February 7, 1932, claims an insecticide consisting «f an 
extract of a rctenone-bearing root in aliphatic hydrocarbons, especially 
petroleum, hexachloroethane, ammonium linoleate and water. An example 
is derris powder 7 parts, hexachloroethane 12 parts, ammonium linoleate 
4 parts, petroleum 25 parts, methyl salicylate 2 parts, and water 50 
parts. 
Schotte and Gornitz (368), assignors to Schering-Kahlbaum A-.GL 
of Berlin, in U. S. patent 2,024,392, issued December 17, 1935, applied 
for December 12, 1933; in Germany November 13, 1931, claim an insecti- 
cidal preparation consisting of a mixture containing rotenone and veratrin. 
They state: 
"As is well known to those skilled in the art, 
insecticides prepared from the roots of plants belonging 
to the genus Derris, Lonchocarpus and others and containing 
