518 
ON  ACONITE. 
of  crystallizability.  Moreover,  at  the  same  Exhibition  I  showed 
small  specimens  of  the  same  alkaloid  crystallized  in  its  free  state, 
as  hydrochlorate,  hydriodate,  and  nitrate,  which  some  two  years 
before  I  had  prepared  by  a  process  which  I  will  proceed  to  ex- 
plain, first  observing  that  it  is  one  of  general  application. 
I  prepare  a  strong  tincture  of  aconite,  by  macerating  for  about 
a  week  5  lb.  of  coarsely-powdered  aconite  root  in  1  lb.  of  methy- 
lated spirit,  acidulated  with  2J  oz.  of  strong  hydrochloric  acid. 
The  materials  being  of  less  value  than  my  time,  I  simply  express 
the  fluid  (leaving  about  one-sixth  in  the  marc  unrecovered)  add 
to  it  half  a  pint  of  water,  and  distil  off  the  spirit.  During  the 
distillation  the  resin  and  oil  gradually  separate,  leaving  the  basic 
matters  in  possession  of  the  acid  watery  fluid  left  in  the  retort. 
It  is  poured  from  thence  to  an  open  basin,  and  the  last  traces  of 
spirit  chased  off.  When  cool,  the  clear  liquid  is  separated  by 
pipette  and  filter  from  the  thick  oily  mass  floating  on  it.  This 
operation  requires  both  time  and  patience,  but  it  is  advisable  to 
do  it  well,  and  completely  purge  the  liquid  of  matters  insoluble 
in  acidulated  water.  To  the  clear  liquid  add  a  slight  excess  of  a 
strong  solution  of  iodohydrargyrate  of  potash ;  heat  gradually 
the  resulting  thick  creamy  fluid  to  about  100°,  stirring  the  while, 
and  separate  the  concrete  resinous  mass  that  results.  In  this 
way  I  have  got  on  the  average  an  ounce  of  crude  iodohydrargy- 
rate to  decompose  which  is  the  next  business.  The  best  way  to 
do  this  is  to  dissolve  it  in  hot  methylated  spirit,  and  add  a  slight 
excess  of  nitrate  of  silver  in  hot  watery  solution.  By  this  means 
the  whole  of  the  iodine  is  removed  in  the  simplest  wayT  but,  it 
may  be  objected,  not  in  the  most  economical,  as  a  slight  loss  may 
be  expected  when  the  iodide  transferred  to  the  silver  bottle 
arrives  at  its  appointed  time  for  reduction.  The  loss,  however, 
is  so  small  as  not  to  be  worth  consideration  when  the  process  is 
followed  on  an  experimental  scale  only.  In  the  large  way  I 
should  treat  it  first  with  sulphide  of  ammonium,  then  with  acetate 
of  lead.  It  is  necessary  to  use  both,  as  I  find  the  lead  alone  re- 
moves only  half  the  iodine,  the  remaining  half  interfering  greatly 
with  the  subsequent  operations.  But  by  first  removing  the  mer- 
cury as  sulphide,  and  then  using  the  lead,  the  liquid  is  completely 
cleared  of  that  troublesome  element.    I  could  not  at  first  under- 
