- 39 - 
InetitTite by, a worker from ftach Ir-.boratory, usin^ both general methods and 
tho S'^iveral .purific'itlon schemos. There waa ^oo'^ agreemei^t "between values 
obtained b;/ the two workers. Agre-?r]3nt between methods I and II was also 
f-enerally good. .It was pointed out that earlier diccrepancies might have 
boon due to the fact that at one laboratory the carbon tetrachloride used 
for cryfltallication was prepared by dissolving the theoretical weight r>f 
rotonone in th^^ solvent v/hile at the other an excess of crystals was kept 
iij the sol\-ent in the refrigerator. The former method was now agreed to 
bf^ the bettor. 
SoTce analyses were made by the two general methods and using titra- 
tion to determine purity (c7) . In method I abnormally high results were 
obtained on the Kinta-typa root, but in method II, a.fter removal of alkali- 
solubla material, this root gave values that agreed with previous figures 
by. other methods of measuring purity. The titration method appf»ared to be 
applicable only to solvates of a certain degree of p-urity. 
In 1939 C^^hn sjid Boem (l6) confirmed the finding of Jones that the 
dichloroacetic acid and 'alcohol-recovery procedures gave substantially 
the same results. The relation between rotenone content and values by 
the Goodhue (40) color' test was studied fui'ther. There was found to be an 
approximate relation between the values by this test end. the pure-rotenone 
content, but the correl'ition was more exact when crude-rctenone content 
w?*s .considered. , An abnon-ally small difference between Goodhue value and 
rctenone content was said tc indicate the presence of Sumatra-type root- 
or extract. ■ 
In 1939 GrahajTi (46) reported that, in the an.alysis of cube powders 
by the chloroform-extraction method, higher percentages of rotenone were 
obtained, and the rctenone-carbon tetrachloride solvate crystallized more 
readily Piid was purer v/aen decolorising carbon was used in the extraction 
flask, \vnen 10 gsi. (Forit-A)' was mixed with 30 gm. of cube powder and 
extracted in the usual way, the values for rotenone were from 0.5 to 0.8 
percent higher than when no carbon was used^ The use of carbon with the 
derris tested caused no significant difference in the results for rotenone. 
Braak (9) in 1939 reviewed the resxilts of analysis of the sample 
of derris root submitted by the Dutch 5ast Indies authorities to various 
laboratories throughout the v;orld and which previously had been reported 
by Koolhaas and L^eijer (see p. 26), Praak also gave the results obtained 
on another sample of derris prepar^^d in the Laboratory for Chemical He- 
search at Euitensorg, Java, and submitted to the laboratories of Seil, 
Putt, and Rusby in Nev/ York and of Salairion and Seaber in London. The 
spinpla, with approximately 6.5 percent of rotenone end 22 percent of 
total extract, w.as analyzed by the methods of Seil (see p. 25) using 
longer extraction time, Jones' and Graham (72_)i Seaber ( ill ) , and Koolhaas 
(78). The Laboratory for Cheviical Research and Soil, Putt, and Imsby, ~ 
when applying the method of Jones and Graham, obtained practically iden- 
tical results both for pure and crude rotenone. The Laboratory for 
Chemical Research found that the values for crude rotenone by the Jnnes 
and Granam method were almost the same as those for pure rotenone by the 
method of Koolhaas. The method of Seaber gave very different results when 
applied in the Dutch East Indies and in the commercial laboratory in London 
