Amoct%?iarm-}  Constituents  of  Rhizoma  Podophyllu  48 5 
solution  is  allowed  to  stand  for  two  hours  before  titrating.  After 
allowing  the  tests  to  stand  two  hours,  40  or  50  cc.  (10  per  cent.) 
potassium  iodide  solution  (the  latter  quantity  for  drying  oils)  and 
120  cc.  water  added  and  the  excess  of  iodine  titrated  with  the 
sodium  thiosulphate  solution.  Should  the  chloroform  solution  of 
the  oil  become  cloudy  during  the  two  hours,  more  chloroform  must 
be  added.  Working  after  this  method  the  following  iodine-absorp- 
tions were  obtained:  Linseed  oil,  1 72-180;  hempseed  oil,  175-176; 
poppyseed  oil,  139-143;  sesame  oil,  106-109;  cotton-seed  oil, 
110-115;  crude  rape  oil,  100-108;  refined  rape  oil,  100-107 ; 
arachis  oil,  9I-2-IOI-5  ;  olive  011,79-84(88);  bone  oil,  59-1-817. 
It  is  worthy  of  attention  that  the  drying  oils  by  this  procedure  give 
much  higher  figures  than  those  published  by  Hubl ;  in  the  case  of  lin- 
seed oil  Hiibl  gave  I  56-160  ;  the  difference  is  caused  by  using  a  very 
considerable  excess  of  iodine  from  the  beginning,  thus  insuring  a 
more  complete  absorption. — Chemisches  Repert.,  1891,  228. 
CONSTITUENTS  OF  RHIZOMA  PODOPHYLLI.1 
By  R.  Kursten. 
The  results  of  the  present  investigation  supplement  the  work  done 
by  Podwyssotzki  (1882).  The  podophyllotoxin  prepared  by  Pod- 
wyssotzki's  method  was  not  constant  in  composition,  and  its  melting 
point  varied  from  100°  to  1250;  further,  the  podophyllic  acid  of  that 
author  is  composed  mainly  of- a  crystallizable,  active,  but  very  impure 
substance. 
Podophyllotoxin,  C23H2409  -f-  2H20,  is  obtained  by  extracting  the 
coarsely  powdered  rhizome  with  cold  light  petroleum,  until  freed 
from  fat ;  after  drying  in  the  air,  the  extraction  is  continued  with 
chloroform,  until  the  liquid  comes  away  almost  free  from  yellow 
color.  As  it  is  not  possible  to  work  with  alcohol-free  chloroform, 
too  prolonged  extraction  with  chloroform  would  yield  a  more 
impure  -extract.  The  chloroform  extract  is  distilled,  and  the  residue 
is  dried  over  a  not  too  warm  water-bath,  partially  dissolved  in  ben- 
zene, filtered,  and  the  filtrate  allowed  to  remain  from  3  to  8  days, 
when  a  brownish-yellow  mass  of  well-formed,  thick,  strongly  refrac- 
tive prisms  is  produced,  which  is  purified  by  washing  with  50  per 
cent,  alcohol,  then  with  ether,  recrystallizing  first  from  boiling  ben- 
1  Arch.  Pharm.  (1891),  229,  220-248.;  Jour.  Chem.  Soc,  Sept.,  p.  1133. 
