- 21 - 
To 50 gm. 01 the plant material 250 cc. of chloroform is 
added in a 500- cc. "beaker, which is covered with a watch 
glass and allowed to stand 6 hours, with occasional stir- 
ring. The chloroform solution is then filtered, and the 
mass on th'j filter is washed with 50 cc. of chloroform. The 
filter with the mass on it is replaced in the same "beaker, 
and 100 cc. of chloroforin is added. The mass is stirred again 
and allowed to stand overnight. Then the chloroform is filtered 
through a new filter and the mass washed with another 100 cc. 
of chloroform in two 50-cc . portions. The chloroform is eva- 
porated completely from the combined filtrates, the last traces 
being removed by stirrine the flask carefully while holding 
it over a naked flame and blowing a current of carbon dioxide 
through it. The extract freed from chloroform is dissolved 
in 20 cc. of carbon tetrachloride by boiling londer a reflux 
condenser for several minutes. Upon cooling rctenone separates 
as rotenone-carbon tetrachloride solvate. '>fnen crystallisation 
is retarded, the solut-ion is seeded with a small quantity of 
solvate. The mass is kept o-'-ernight in an ice chest to ensure 
comr)lete crystallization. The separated solvate is collected 
by suction in a tared (fritted) glass crucible, v/ashed with 
about 15 cc . of carbon t=^trachloride (sat^orated with rotenone) 
in small portions, and dried overnight to constant weight (in 
air at room temperature). 
In another article in the san^e year Rowaan (105) compared results 
obtained on authentic derris samples by a modification of Hoark' s method 
( 100 ) and by the polarimetric method of Danckwortt and his coworkers (25). 
He recommended the extraction methods of P.oark or of Jones (62) or modifi- 
cations of them as the most workable for the determination of rotanone. 
In the course of a study by Tattersfield and I.'artin (120) in 19.35 
of tae evaluation of derris root, deterninations of rotenone were made on 
the same samples both in Lialaya, the sc-irce of the material, and at 
Hothamsted , England. In Malaya rotenone was determined by the method of 
Oaorgi and Teik (34). At P-othamsted a 50-gm. sample was extracted v/ith 
ether and the extract was freed of solvent and dissolved in carbon tetra- 
chloride; the crude solvate obtained v/as recrystallized from alcohol. 
E-otanone was also determined by th'^ trichloroethylene method of Cahn and 
Boam (13). In one say.iple an extraction was also made v/ith chloroform. 
The values obtained for rotenone by these various methods v/ere in general 
in good agreement. The rotenone content of the samples ranged from about 
2 to about 10 percent. In working with the method of Takei , Kiya.jima, 
and Ono (118) the vn^iters found that in some samples much less rotenone 
could b'=^ crystallized out from ether by th^ preliminary crystallization 
recomp^ended by Takei and his coworkers than was separated by the Jones (62) 
method from carbon tetrachloride. 
In further work on t^.e evaluation of rotenone-containing plants, 
Martin and Tattersfield (84) in 1936 studied the effect of removing the 
toxicarol upon tie separation of rotenone from carbon tetrachloride solu- 
tions of Sumatra- tyiDe and Derris malacoansie resins. It was found that. 
