ON  COLCHICIA. 
101 
alkalies  upon  colcliicia  and  does  not  pre-exist  in  the  seeds  of  col- 
ehicum.  Pure  colcliicia  in  doses  of  '05  grm.  killed  dogs,  but  did 
not  affect  rabbits  in  doses  of  *1  grm. 
The  collection  of  chemicals  in  the  Philadelphia  College  of 
Pharmacy  contains  a  specimen  of  colchicia  prepared  by  Mr. 
Carter  in  1857 ;  a  portion  of  this  was  used  for  the  purpose  of 
clearing  up  the  contradictions  in  the  statements  of  the  above 
authors.  The  substance  is  a  light  yellow  amorphous  powder, 
possessing  a  very  faint  odor  and  intensely  bitter  taste,  sparingly 
soluble  in  ether,  but  easily  soluble  in  water  and  alcohol,  the 
aqueous  solution  being  slightly  turbid,  most  likely  in  consequence 
of  the  decomposition  of '  a  small  portion  into  resin  and  colchicein. 
Heated  upon  platinum  foil,  it  fuses  ;  at  a  higher  heat,  it  takes 
fire  and  burns  without  leaving  any  residue.  Placed  upon  moist- 
ened red  litmus  paper,  the  blue  color  is  restored  ;  very  faintly 
reddened  litmus  becomes  blue  also  by  a  concentrated  aqueous 
solution.  One  drop  of  dilute  sulphuric  acid  dropped  from  a 
bottle  giving  fifty-two  drops  to  the  flu i drachm,  consequently 
about  one-eighth  of  a  grain  HO,S03,  when  mixed  with  one  grain 
of  colchicia,  retained  its  acid  reaction.  One  drop  of  the  acid 
was  mixed  with  one  fiuidounce  of  distilled  water ;  in  five  minims 
of  this  mixture,  equal  to  about  one-seven  hundred  and  seventieth 
grain  HO,S03,  one-sixteenth  grain  colchicia  was  dissolved  and 
the  solution  now  had  a  distinct  alkaline  reaction  on  slightly  red- 
dened litmus  paper;  but  on  heating  this  solution  to  the  boiling 
point,  it  had  acquired  an  acid  reaction.  It  will  be  seen  that  two 
important  statements  of  Mr.  Carter  are  corroborated,  namely, 
the  alkaline  reaction  of  colchicia  and  its  power  to  destroy  the 
acid  reaction  of  sulphuric  acid. 
The  behaviour  of  colchicia  towards  reagents,  I  found  to  be  as 
described  by  the  authors  quoted  above  ;  the  most  important  tests 
for  recognizing  the  presence  of  colchicia,  are  its  behaviour  to 
dilute  acids  and  also  alkalies,  by  which  its  solution  acquires  a 
yellow  color,  and  the  violet  and  blue  color  which  is  produced  by 
oxidizing  agents  with  dry  colchicia.  This  latter  coloration,  which 
changes  through  various  shades  finally  into  yellow,  is  strikingly 
beautiful  when  concentrated  sulphuric  acid  is  used  and  immedi- 
ately some  nitric  acid  or  a  fragment  of  a  nitrate  is  added ;  strong 
