454 
THE  PREPARATIONS  OF  CONIUM,  ETC. 
prepared  extract,  daily  for  a  year,  without  result.*  Dr.  Allbutt, 
of  Leeds,  informs  me  that  he  "  has  often  given  the  extract,  in 
doses  so  large  as  to  nauseate  by  its  mere  mass,  without  other 
results." 
It  thus  appears  conclusively  that,  from  the  time  of  its  intro- 
duction to  the  present  day,  the  extract  has  been  regarded  by 
many  as  an  uncertain  preparation,  and  it  is  remarkable  that  its 
value  has  not  been  long  ago  more  satisfactorily  determined. 
Christison,  Geiber,  Orfila,  Pereira,  and  others,  all  concur  in  the 
opinion  that  most  of  the  extract  of  conium  of  the  shops  is  inert 
or  nearly  so.  Pereira  states  that  he  was  unable  to  procure  any 
sensible  quantity  of  conia  from  giv  of  the  extract. f  The  obser- 
vations on  the  extract  are  concluded  in  his  work  by  the  following 
statement,  which  is  accepted,  I  believe,  as  a  pharmaceutical 
axiom: — "  The  goodness  of  the  extract  maybe  determined  by 
the  disengagement  of  a  strong  odor  of  conia,  when  it  is  gradually 
triturated  with  liquor  potassae."  This  test  is  so  readily  applied, 
and  appears  at  the  same  time  so  decisive,  that  any  more  elabo- 
rate analysis  seems  superfluous,  and  yet  I  venture  to  assert  that 
no  statement  can  be  further  from  the  truth,  no  test  more  falla- 
cious. Half  an  ounce  of  extract,  containing  but  a  fraction  of  a 
grain  of  conia,  will,  on  trituration  with  caustic  potash,  speedily 
evolve  a  powerful  and  penetrating  odor  of  conia,  and  the  effect 
is  usually  very  much  heightened  by  the  simultaneous  separation 
of  a  little  ammonia.  A  great  d.  al  too  much  has  been  inferred 
from  this  reaction,  -  and  it  is  to  this  cause,  I  believe,  that  we  have 
so  long  remained  in  a  state  of  uncertainty  respecting  the  virtue 
of  the  extract.  A  given  sample  has  been  pronounced  good,  be- 
cause, on  commixture  with  caustic  potash,  it  has  evolved  a  strong 
odor  of  conia.  Attention  to  the  following  experiments  will  show 
the  fallacy  of  such  a  conclusion. 
I  have  already  proved  that  the  "  succus  conii "  prepared  last 
season  by  Mr.  Buckle,  of  Gray's  Inn  Road,  possesses  in  a  power- 
ful degree  the  poisonous  properties  of  hemlock.  As  many  sources 
of  error  are  by  this  means  eliminated,  I  am  fortunate  in  being 
*  Obs.  on  the  Use  of  Hemlock,  John  Fothergill,  M.  D.,  Works,  vol.  ii. 
p.  59. 
f  Elem.  Mat.  Med,  vol.  ii.  pt.  ii.  p.  206. 
