THE  PREPARATIONS  OF  CONIUM,  ETC. 
457 
experiments  that  all  extract  of  conium  is  as  deficient  in  medicinal 
power  as  the  samples  employed  in  these  experiments  have 
proved  to  be.  Still,  side  by  side  with  the  facts  referred  to  in 
this  paper,  they  strongly  persuade  one  to  this  view.  The  facts, 
indeed,  of  the  particular  cases  before  us  are  very  strong.  The 
juice  employed  in  the  preparation  of  the  extracts  has  been 
proved,  both  physiologically  and  chemically,  to  he  replete  in  act- 
ive properties, — f  =j  of  the  "  Succus  Conii  "  =  f  3vj  of  the  juice 
of  the  plant,  and  30  grains  of  extract  has  been  shown  to  contain 
0*42  grains  of  conia ;  and  every  precaution  was  taken  with  the 
expressed  juice  to  prevent  decomposition  by  exposure  to  the  air, 
to  a  high  temperature,  or  to  prolonged  heat ;  and  yet  we  find 
that  250  grains  of  it  retain  only  a  grain  of  the  alkaloid.  Again, 
two  ounces  of  the  dried  leaf — equivalent  to  f  ,$vj  of  the  juice  of 
the  plant,  and  to  very  nearly  4  grains  of  conia — retain  less  than 
half  a  grain  of  the  active  principle.  I  say,  then,  that  in  face  of 
these  facts,  there  is  a  very  strong  body  of  evidence  against  the 
medicinal  value  of  the  extract. 
With  a  view  of  determining  what  becomes  of  the  conia  during 
the  process  of  evaporation,  I  have  conducted  the  following  ex- 
periments : — 
1.  Evaporated  f  aj  of  the  Succus  Conii,  P.  B.,  No.  1,  over  a 
water-bath  to  the  ordinary  consistence  of  the  extract.  About  an 
hour  was  required  for  the  operation.  After  liberating  the  conia, 
and  completely  removing  it,  I  found  that  it  weighed  0*30  of  a 
grain,  0*12  less  than  I  obtained  by  the  same  process  from  the 
same  quantity  of  the  succus,  to  which  I  had  previously  added 
f  £ss  of  dilute  sulphuric  acid,  P.  B.,  in  order  to  fix  the  conia. 
2.  Placed  f  ^j  of  the  same  sample  of  "  Succus  Conii "  in  a  re- 
tort, and  distilled  f  3iiiss  by  the  aid  of  a  water-bath.  The  dis- 
tillation occupied  three  hours.  The  first  f  ^iss  passed  over  du- 
ring the  first  fifteen  minutes,  and  was  collected  separately.  Ex- 
cepting that  the  first  fluid  was  chiefly  spirit,  the  distillates  did 
not  appear  to  differ  ;  both  possessed  a  stronger  odor  of  the  plant 
than  the  succus  itself;  both  gave  out  an  extremely  faint  odor  of 
conia  on  the  addition  of  caustic  potash,  both  were  rendered 
faintly  opalescent  by  the  addition  of  nitrate  of  silver  and  of 
chloride  of  mercury.    The  remainder  was  transferred  from  the 
