"^'"sept^'^issT'^'"' }  P^epGLii'(^tion  and  Composition  of  Colchiein.  449 
a  little  water,  the  solution  filtered,  and  evaporated  upon  the  steam- 
bath  in  vacuo. 
After  repeating  this  operation  three  times,  a  product  was  obtained 
which  was  but  slightly  colored,  and,  after  incomplete  drying,  was 
decomposed  by  heating  0'736  gram,  dissolved  in  15  grams  of  distilled 
water,  with  15  drops  of  25  per  cent,  hydrochloric  acid,  at  the  temper- 
ature of  the  steam-bath,  in  a  sealed  tube.  The  amount  of  beta-col- 
chicoresin  thereby  formed  was  scarcely  weighable,  while  the  yield  of 
colchicein  was  0*695  gram,  or  94*929  per  cent,  of  the  applied  colchi- 
ein, and  the  residue  from  the  mother-liquid  amounted  to  0*105  gram, 
or  14*268  per  cent. 
In  regard  to  the  relation  of  the  different  products  of  decomposition 
to  colchiein,  the  following  conclusions  may  be  drawn  from  the  results 
of  the  above  experiments  : 
Colchiein,  by  heating  with  mineral  acids,  is  converted  by  the  elimi- 
nation of  a  molecule  of  water  into  colchicein,  which,  in  the  act  of  sepa- 
ration, combines  with  2  molecules  of  water  of  crystallization.  By 
heating  with  water,  colchicein  is  again  inversely  converted,  through 
the  absorption  of  one  molecule  of  water,  into  colchiein. 
C„H,3NOe   =    C„H,.NO,    +  H,0 
Colchicin.  Colchicein. 
Three  molecules  of  colchiein  lose,  by  exposure  to  the  air,  1  mole- 
cule of  ammonia  and  3  molecules  of  water,  with  the  formation  of  col- 
chicoresin. 
3(C„H,3NO,)    =    Q,H,„N,0,,    +    NH,    +  3H,0 
Colchiein.  Colchicoresin. 
By  the  further  elimination  of  ammonia,  so  that  two  molecules  of 
colchiein  lose  one  molecule  of  ammonia  and  two  molecules  of  water, 
beta-colchicoresin  is  formed. 
_  2(C„H,3NO,)    =    C3,H3,NO,„    +    NH,    +  2H,0 
It  is,  however,  considered  most  probable  that  beta-colchicoresin  is 
formed  from  colchicoresin  according  to  the  following  equation  : 
2(Q,H„„N,0,,)    =    3(C3.H3,NO,„)    +  NH, 
In  regard  to  the  residue  from  the  mother-liquid,  the  author  states 
that  this  substance  can  be  brought  in  no  direct  connection  with  colchi- 
ein, but  it  is  not  improbal)le  to  accept  that  it  is  formed  from  portions 
of  colchicein  and  beta-colchicoresin  remaining  dissolved  in  the  mother- 
29 
