ON  COLCHICTA. 
103 
The  resinous  matter  remaining  on  the  filter  when  colchicein 
is  filtered  off  was  dissolved  in  alcohol,  and  the  solution  evapo- 
rated ;  an  amorphous  brown-greenish  mass  was  left,  in  which 
alcoholic  solution  has  a  decided  acid  reaction.  Concentrated 
nitric  acid  dissolves  it  with  an  evanescent  yellow  color  ;  on  the 
addition  of  sulphuric  acid  the  solution  takes  place  with  a  pur- 
plish-brown, rapidly  disappearing ;  pure  sulphuric  acid  dissolves 
it  with  a  brown  color. 
Having  looked  in  vain  in  every  portion  of  the  decomposed 
colchicia  for  glucose,  or  a  compound  which  would  reduce  an  alka- 
line solution  of  copper,  the  observations  of  Oberlin,  Ludwig  and 
Hubler  are  confirmed. 
Taking  all  these  results  together,  no  doubt  colchicia  must  be 
looked  upon  as  an  alkaloid,  the  salts  of  which  are  soluble  in 
water,  but  decomposed  with  the  formation  of  colchicein,  on  keep- 
ing them  in  solution  as  well  as  on  evaporating  them.  The  crys- 
talline mass,  obtained  by  Mr.  Carter  on  evaporating  sulphate  of 
colchicia,  was  undoubtedly  colchicein. 
Aschoff  and  Bley  observed  already  that  colchicia  combines 
with  bases,  and  that  when  it  is  evaporated  with  a  solution  of  the 
carbonate  of  an  alkali,  the  residue  contains  no  carbonic  acid. 
Hubler  makes  it  probable  that  colchicein  is  formed  under  these 
circumstances.  Colchicia  is  a  very  weak  base,  and  colchicein, 
if  it  can  be  regarded  as  an  acid,  is  certainly  a  weak  one,  and 
resembles  the  alkaloids  in  its  behavior  to  some  reagents.  If 
colchicia  and  colchicein  have  the  same  composition,  the  acid 
resin  formed  together  with  the  latter  can  scarcely  be  different. 
In  preparing  colchicia,  the  action  of  alkalies  and  acids,  parti- 
cularly when  heat  is  applied,  must  be  avoided. 
Regarding  the  officinal  preparations  of  colchicum,  requiring 
the  application  of  heat,  the  two  fluid  extracts  must  contain  col- 
chicia in  its  natural  state  of  combination  ;  extractum  colchici 
aceticum,  however,  contains  colchicein.  I:  would  be  interesting 
to  ascertain  how  long  colchicia  is  found  in  the  officinal  wines 
before  it  is  partly  or  entirely  converted  into  colchicein  ;  the 
similarity  of  their  reactions  will  increase  the  difficulties  of  their 
separation  without  farther  decomposition  of  the  alkaloid,  while 
it  facilitates  the  discovery  of  colchicum  in  cases  of  poisoning. 
