57 
necesst-ry to S: =d the solution with the carbon tetrachldrids 
solvate of deguelin at 0° C. and let it stand o\'erni^ht for 
complete crystallization. The crystals are then filtered on 
a tared Gooch cracihle, vashed with cold car^bon tetrachloride 
saturated with deguelin, air-dried at room temperature for 4 
hours, and wei^fed as the 1;1 daguelin-carbon tetrachloride 
solvate. 
The amOTint of deguelin in this iinpuro solvate is deter- 
mined by the red color test (40). It is assumed that deguelin 
alone is responsihle for the color, and the fact that racemic 
deguelin 5^ives only 80 percent of the color given by rotenone 
is taken into consideration when rotenone is us?d vs the standard 
of comparison. The effect of , solubility in the solvents used 
is comoens^.ted for by adding 0.08 percent when 5 cc. of carbon 
tetrachloride is us:?d for crystallization and 0.11 percent when 
10 cc . is used. 
The accuracy of the method was checked from several angl'^s and it appeared 
that no great error vras introduced. The possibility of decomposition of 
deguelin during the racemiz^tion was studied by using a concentrated sample 
of active deguelin oreo^red by hi/^ .— vticuum distillation. Upon raccwizatiOR 
of this 'aatei-ial* 83 perdsnt of "inactive deguelin v&3 obtained. Kence not 
more than 17 percent was believed to be destroyed in the racemization and 
probably much less, as the active deguelin was not pure. The precision 
was said to be equal to that of the rotenone analysis (72) . Results for 
deguelin by this method were markedly lower than those by either the red 
color test (40) or the dehydro method (l20) . For example, on 13 samples of 
derris and cube values by racemization raaiged from less than one-tenth to 
about four-tenths of those by the red color test. It v;as pointed out that 
some of this difference mi^-t be due to compounds other than deguelin that 
give the color test or dehydro derivatives. 
As in previous work on the evaluation of rotenone-containing plants, 
Martin ^83) in 1940 made qiiantitative determinations of the amounts of, 
"deguelin concentrate" in several samples of derris. The method was .similar 
to that employed in the earlier investigation (84)with certain modifications. 
The roots vjere extracted by percolation with ethyl acet-^te for 3 hours in- 
stead of by prolonged extraction v;ith petroleiam ether in a Soxhlet. Alkali 
extraction of the resins in ether solution v;as carried out before crystal-it- 
lization of the rotenone. In the c-^se of roots rich in rotenone a mixture 
of ether and benzene was used as solvent for the extract during the alkali 
extraction. This scheme, which prevented crystallization of the rotenone 
during the extraction, has already been mentioned in connection with the 
determination of rotenone (59), After separation of the rotenone as the 
carbon tetrachloride solvate, the residual resin was designated the "deguelin 
concent ratei" It was also stated that an assessment of the "deguelin con- 
centrate" was obtained simply by subtracting from the percentage of "neutral 
resin" (alkali-insoluble material) the percentage of purified rotenone. 
