- 2 « 
4 i?ji^5duction 
An attempt has been made to collect all references to riethocs used 
for the cherdcal analysis of rotenone-bearing pl?iits, particularly of 
derris aiid cu"b3 roots. The co.iipilation nas "been corfined to articles 
descri-oing rnethcds or criticallv comparinfl: results obtained ty different 
methods. Iteferences {ri-?rinf: only results of ar^alysic or reviews ccntslning 
no original contributions or critical observations hav? net been included. 
Likewise methods of utilizing the results of chenical analysis, directly 
or t^irough various calculations, to obtain a nieasurs of insecticidal effec- 
tiveness are- not treated here. This problem is itself sufficiently dis- 
tinct and important to require separate treatment. 
The methods discussed here have been f::rcuped primarily accordinr 
to the subntances which they d^-Ptermine . This classification, although 
difficult because of uncertainty as to .iupt what substances are determined 
by many of the methods, was believed to be the most useful. At the end 
of the sections on methods for determining; the more important constituents, 
a brief statenient has been mads of the present status of methods for the 
purpose. In the last tvo sections are grouped certain methods that give 
more or less empirical values, which it is difficult or imoossible to 
interpret in terns of actual substances present in tne sajcple , 
SAtrpLING 
In this section only those few articles are reviewed which give 
specific details on the s.amplin^ of derriv; or cube root for analysis. 
Georgi and Teik (74) in 1933 surgestsd a procedure to be followed 
in selecting a sample for analysis from a s'iipmriint of derris root. 
In 1936 these authors (35) elaborated the method somewhat, so that, 
for the preparation of fresh roots, the proced'ore was as follows: 
"Fresh roots are sun-dried until they can be broken 
without ey:udation of plant -.juices. Th^ serai-dried roots are 
then c":t into pieces ^'arying from l/4 to 1/2 inch long and the 
chopp<*d naterial is further sun-dried until of constant wei^^ht. 
The j-'terial is then quartered for analysis until s.r)proximately 
1/4 lb. remains. One h\indred grarr.s are v/oighed, then ground in 
a drug mill. The root is first passed througn a disint-^grator 
having spaces l/32 inch v;ide, the spaces bein^ appror.ir.ately 
1/4 inch apart. Tho naterial is .gro^iond a second tim-:; , the dis- 
integrator being r-'^placed by a 1 mm. sieve. The srr;ail anount 
of woouy matter reniaininr is ground separately in a small mill 
and incorporated with the main ssmnle . To obt^-in a representative 
sample of the ground root for analysis, the varicii.s fractions are 
shaken together in a .iar provided v;ith a closoly-fitting lid, and 
the required amount of material io weighed before segregation of 
the fine particles h^s taken place." 
