''^"sept'^'issT™  }  J^^'^pGLTation  and  Composition  of  Colchicin.  443. 
ON  THE  PKEPARATION  AND  COMPOSITION  OF  COL- 
CHICIN, AND  ITS  RELATION  TO  COLCHICEIN  AND 
SOME  OTHER  PRODUCTS  OF  DECOMPOSITION. 
By  Johann  Hertel. 
Abstracted  from  "Pharm.  Zeitschrift  fur  Russland,"  Nos.  14  to  18,  pp.  245-320, 1881.   By  Fred.  B.  Power.. 
In  his  interesting  essay,  the  author,  before  proceeding  to  describe 
the  results  of  his  own  experiments,  reviews  the  history  of  colchicin 
and  the  results  of  the  investigations  of  Pelletier  and  Caventon,  Geiger 
and  Hesse,  Oberlin,  Hiibschmann,  Souberan,  Ludwig  and  Pfeiffer,, 
Hiibler,  Reithner,  Schoonbrood,  Eberbach,  Walz,  Maisch,  Aschoff,. 
Boemeister,  Bley  and  others,  and  calls  attention  to  the  fact  that  com- 
mercial colchicin  is  not  a  pure  product,  but,  as  obtained  by  the  evapo- 
ration of  an  alcoholic  tincture,  consists  of  a  mixture  of  colchicin  with 
fruit  sugar  and  other  impurities,  and  that  even  the  article  designated 
as  "  colchicinum  purum contains,  as  a  rule,  but  from  10  to  20  per 
cent,  of  pure  colchicin. 
In  connection  with  the  method  employed  by  different  chemists  for 
the  isolation  of  colchicin,  which  from  time  to  time  have  been  vari- 
ously modified,  the  author  suggests  the  following  method  of  prepara- 
tion, as  being  the  most  readily  executed,  and  affording  the  largest 
yield. 
The  entire  seeds  are  digested  in  a  displacement  apparatus  with  fresh 
portions  of  85  per  cent,  alcohol  until  the  outflowing  liquid  appears 
simply  of  a  light  yellow  color,  for  which  purpose  the  renewal  of  the 
alcohol  four  times  is  sufficient,  and  finally,  in  order  to  extract  the  last 
portions  of  the  colchicin,  boiling  alcohol  is  employed.  The  united 
liquids,  which  possess  a  slight  acid  reaction,  are  treated  with  calcined 
magnesia,  the  whole  well  shaken,  filtered  after  standing  for  some 
hours,  and  the  alcohol  finally  distilled  off  by  means  of  a  steam-bath,. 
in  vaouo,  until  the  residue  has  the  consistence  of  a  liquid  extract;  if 
the  distillation  takes  place  under  ordinary  atmospheric  pressure,  more 
time  is  required,  and  by  too  long  an  exposure  to  heat  considerable 
diminution  in  the  yield  is  experienced.  The  residue  in  the  retort 
is  mixed  with  about  ten  times  its  amount  of  water,  the  oily 
matter,  which  separates  upon  standing  on  the  surface  of  the  liquid^ 
removed,  the  liquid  filtered,  and  repeatedly  shaken  with  chloroform 
until  the  latter  remains  nearly  colorless ;  if  the  colchicin  is  thus  com- 
pletely removed,  the  liquid  possesses,  after  the  dissipation  of  the  dis- 
