444  Preparation  and  Composition  of  Colchicin.  {^^^^^^'i^i^^' 
solved  chloroform  by  warming,  a  sweet  honey-like  taste.  The  chloro- 
form is  then  distilled  off  until  the  residue  assumes  the  consistence  of 
syrup,  which  is  spread  upon  glass  plates  and  warmed  for  an  hour  at  a 
temperature  of  from  80  to  100°C.  until  the  last  traces  of  chloroform 
Jiave  completely  evaporated. 
As  thus  obtained,  colchicin  forms  an  amorphous,  brown,  brittle 
mass,  which  may  be  purified  by  again  dissolving  it  in  about  twenty 
times  its  weight  of  water,  whereby  the  coloring  matter,  which  is  insol- 
uble in  water,  remains  beliind.  The  solution  is  then  filtered  and  sub- 
sequently evaporated  in  a  shallow  capsule.  In  this  manner  the  yield 
of  pure  colchicin  amounted  to  from  0*38  to  0*41  per  cent.,  the  yield 
being  larger  when  the  entire  seeds  instead  of  the  previously  ground 
seeds  are  employed,  as  from  the  latter  a  considerable  amount  of  fixed 
oil,  fruit  sugar  and  mucilaginous  substances  are  extracted,  by  the 
removal  of  which  from  the  colchicin  the  latter  becomes  partially  decom- 
posed. 
In  regard  to  the  chemical  properties  of  colchicin  the  statements  of 
previous  investigators  being  largely  at  variance,  and  in  many  respects 
contradictory,  the  author  has  endeavored  to  ascertain  its  true  nature, 
and  first  directs  his  attention  to  the  substance  to  which  the  color  of 
colchicin  is  due,  and  which  is  named  colchicoresin.  This  substance, 
which  is  obtained  as  a  deposit,  of  a  coffee-brown  color,  when  the  col- 
chicin obtained  from  the  chloroformic  solution,  by  the  above  described 
method  of  the  author,  is  dissolved  in  water,  is  also  formed  when  col- 
chicin is  preserved  for  a  long  time  with  exposure  to  the  air,  or  when 
the  colchicin,  in  contact  with  a  small  amount  of  water,  is  exposed  to 
a  high  temperature;  colchicin  which  has  become  brown  by  heating 
consists  for  the  most  part  of  colchicoresin. 
The  colchicoresin,  after  being  freed  as  completely  as  possible  of  col- 
chicin, by  washing  with  distilled  water,  was  dissolved  in  alcohol, 
the  solution  filtered,  and  evaporated  in  a  shallow  capsule  upon  the 
water-bath.  After  drying,  it  forms  an  amorphous,  dark  brown,  resin- 
ous-like and  brittle,  readily  pulverizable  mass.  It  is  very  sparingly 
soluble  in  cold  water,  but  imparts  to  the  latter,  after  long  standing,  a 
yellow  color;  it  is  more  readily  soluble  in  boiling  water,  the  solution 
becoming  turbid  upon  cooling ;  in  chloroform  and  alcohol  it  dissolves 
readily,  with  a  brown  color,  but  is  insoluble  in  ether.  It  dissolves 
also  in  ammonia  water  and  in  solution  of  potassa,  the  solutions  pos- 
sessing, even  in  a  dilute  condition,  a  brown  color. 
