COLCHICIN'A.  Sgn.  Col'chioinb.  Col-
CHICIA.  A  peculiar  principle  discovered  by
Gieger  and  Hesse  in  the  seeds  of  the  Colchi-
cum  autumnale  or  common  meadow  saffron.  It
also  exists  in  the  corms  or  bulbs.
Frep.  Macerate  the  braised  seeds  in  boiling
alcohol,  add  magnesia,  to  throw  down  the
alkaloid,  digest  the  precipitate  in  boiling  al-
cohol, and  lilter.  By  cautious  evaporation
colchicine  will  be  deposited,  and  maybe  purified
by  re-solution  and  crystallisation  iu  alcohol.
Frop.,  1(0.  Odourless  ;  bitter ;  soluble  in
water  and  alcohol ;  form  salts  with  the  acids.
It  is  very  poisonous.  i');th  of  a  grain,  dis-
solved in  spirit,  killed  a  cat  in  12  hours.  It
differs  frem  voratria  in  being  soluble  in  water
and  crystalline,  and  in  the  non-production  of
sneezing  when  cautiously  applied  to  the  nose.
Strong  oil  of  vitriol  turns  this  alkaloid  of  a
yellowish- brown;  nitric  acid  turns  it  of  a  deep
violet,  passing  into  indigo-blue,  green  and
yellow.     It  is  not  used  in  medicine.
COL'CHICUn.  Syn.  Mba'dow  saf'fbon  j
COLCHICUM  AUTUMNALE  (Linn.),  L.  The
recent  and  dried  corms  or  bulbs  {colchici
oormus),  as  well  as  the  seeds  (colchici  semina),
are  official  in  the  British  Pharmacopceia.  The
corms  are  ordered  to  be  dug  up  in  the  month
of  July,  or  before  the  autumnal  bud  has  pro-
jected. The  dry  coatings  having  been  torn
off,  cut  the  corms  transversely  in  thin  slices,
and  dry,  at  first  with  a  gentle  heat,  but  after-
wards slowly  increased  to  150°  Fahr.
