- 13 - 
Graham (47), in his 1936- report to the Association of Official^, 
Agri cultural • Chemists , gave results of collaborative analyses of one 
sample of (?erris and .on-e of cube root. Results for total ether extract 
were in fair agreement and ranged from 13.7 to 14.5 percent for the derris 
and from 21.1 to 23.3 percent for the cube sample. Details of the method 
were ,no.t given. In his- 1939 report to the same Association Orahajn (49) 
recommended, that the method for total ether extract used in the 1938 work 
be adopted as official. In a discussion (48_) of insecticide analysis 
before the 1939 meeting of the National Association of Insecticide and 
Disinfectant Manufacturers, he described the method briefly. The method 
(2) was given in detail in the Official and Tentative I'ethods of Analysis . 
of the Association of Official Agricultural Chemists. It is as follows: , 
. "Extract 5. g. of finely powdered root in a Soxhlet or 
other efficient extraction apparatus with ethyl ether for 
48 hours. After extraction, concentrate extract and filter 
o.£i' any insolub-le materia,! that may be present. Pceceive 
filtrate in a tared beaker, evaporate off ether on steam 
bath,, and dry in oven at 105°' 0. to constant weight." 
Details of a n'odification of this method to be used on derris and cube 
powder in the presence of sulfur have been furnished by the Agricultural 
'.Marketing Servige (124). The total ether extract obtained essentially as 
in the official method is weighed and then treated as follows: 
Add 25 cc. of acetone (which' hs;S previously been saturated 
with sulfur at room temperature), disintegrate the residue 
with a stirring rod^ and stir until the plant resins are in 
solution; filter, \inder suction, through a. weighed Oooch crucible 
fitted with a disk of filter paper, riiise out the sulfur from 
the bea|?:er, and wash with acetone (saturat'ec' with sulfur). 
Allow the crucible to remain under suction for 5 minutes, and 
then place in an oven at 105*^ C. for 15 minutes. Cool and weigh. 
The weight of this sulf'or residue, subtracted from the weight of 
the residue in the original beaker, represents the ether-soluble 
plant extract material in the sample. 
Among commer-cial firms handling derris and cube root who recently 
firrnished information on.- methods of analysis (private communications), 
McCormick' and Company^,- S. B. Penick and Company, and John Powell and 
Company used procedures for total extract essentially similar to the 
official method. S. B. Penick .and ■Company also used total chloroform 
extract and found this determination more convenient to handle. Derris, 
Inc., used the. ether extract determination only as a check: and ordinarily 
determined total (extract in- con.;' i:inct Ion wita a,nalysis for rotenone. The 
method used b-' this, firm, for deteri^ining rotenone, described in the 
section on Rotenone , involved extraction of the sample with acetone and 
crystallization of the rotenone from carbon tetrachloride. The mother 
liquor from the rotenone separation was then treated as follows: 
The nonrotenone portion (from a 25- to. 50-gm. sample)- in 
carbon tetrachloride- is concentrated to a small, volume, and 
the small amount of carbon tetrachloride remaining is removed 
