208 
ON  COLCHICIA. 
The  alkaloid  was  afterwards  obtained  in  a  state  of  greater 
purity  and  more  plentifully  by  the  following  method. 
Three  pounds  of  the  dried  English  corms  were,  as  in  the  former 
process,  exhausted  by  alcohol,  the  tincture  evaporated  to  a  syrup, 
thrown  into  water  acidulated  with  acetic  acid,  and  the  solution 
filtered.  Solution  of  ammonia  was  added  to  the  liquor  until  it 
was  nearly  neutral,  and  then  solution  of  tannin  as  long  as  a  pre- 
cipitate was  formed.  The  insoluble  tannate  was  separated  from 
the  residual  liquor  by  filtration,  well  washed  with  water,  and  while 
still  moist,  thoroughly  triturated  with  at  least  five  times  its 
weight  of  freshly  prepared  hydrated  oxide  of  lead.  Small  por- 
tions of  alcohol  were  added  from  time  to  time  during  the  tritura- 
tion, until  the  quantity  amounted  to  twelve  fluid  ounces.  The 
whole  was  then  thrown  on  a  filter,  and  the  filtered  liquid  evapo- 
rated at  a  gentle  heat.  Twenty  grains  of  nearly  white  colchicia 
were  obtained  from  the  three  pounds  of  root  employed. 
As  thus  obtained  colchicia  is  in  the  form  of  a  yellowish  mass 
which  becomes  nearly  white  when  powdered,  inodorous,  of  a  bitter 
taste  without  sharpness  or  acrimony.  It  is  not  sternutatory :  a 
portion  was  snuffed  up  the  nostrils  and  occasioned  no  immediate 
effect,  but  after  some  time  an  unpleasant  feeling  of  dryness  in 
the  nasal  passages  was  experienced,  followed  by  a  discharge  of 
thin  mucus  slightly  tinged  with  blood. 
t  It  is  quite  soluble  in  water,  both  cold  and  hot,  and  still  more 
soluble  in  dilute  acids  ;  very  soluble  in  absolute,  officinal,  and 
dilute  alcohol,  both  cold  and  hot ;  sparingly  and  slowly  soluble 
in  pure  ether,  but  quite  soluble  in  commercial  ether  containing 
alcohol ;  very  soluble  in  chloroform,  and  apparently  insoluble  in 
benzole.  It  is  freely  taken  up  by  aqua  ammonise  and  dilute 
liquor  potassae. 
I  have  not  succeeded  in  crystallizing  this  principle.  A  solu- 
tion in  alcohol  allowed  to  evaporate  spontaneously  leaves  the 
colchicia  as  a  varnish  like  mass ;  and  a  precisely  similar  result  is 
obtained  if  chloroform  or  commercial  ether  be  substituted  for 
alcohol.  A  solution  in  distilled  water  or  very  dilute  alcohol, 
when  exposed  to  the  air,  deposits  the  alkaloid  as  a  flocculent 
precipitate  devoid  of  crystallization. 
It  restores  the  blue  color  to  reddened  litmus  paper  if  moistened 
and  laid  on  it,  and  a  portion  added  to  an  infusion  of  litmus,  red- 
