Am juneT'i87h6arm* }         Analysis  of  Fluid  Extracts.  1 5 1 
The  test  solutions  used  were  as  recommended  by  Prof.  DragendorfF 
and  Prof.  F.  F.  Mayer,  and  in  every  case  were  tested,  with  great  care> 
with  the  pure  alkaloids  or  alkaloidal  salts.  The  test  solution  which 
was  adopted  by  the  essayist  was  that  of  the  1-10  normal  solution  as 
suggested  by  Prof.  Mayer,  but  for  convenience  he  calls  it  in  his  essay 
"normal,"  while  that  which  he  calls  1-10  normal  is  really  equivalent 
to  1-100  normal,  as  used  by  Prof.  Maver.  The  detailed  experiments 
are  very  elaborate  ;  in  the  following  a  brief  abstract  of  the  manipula- 
tions is  given: 
50  cc.  of  the  fluid  extract  of  nux  vomica  were  evaporated  to  a  syrupy 
consistence,  acidulated  with  sulphuric  acid,  and  while  warm  mixed 
with  50  cc.  of  water,  then  filtered  to  separate  fatty  matter  and  diluted 
to  100  cc.  On  testing  this  solution,  it  was  observed  that  the  final 
reaction  with  iodohydrargyrate  of  potassium  was  not  sharply  defined  -> 
accordingly,  the  fluid  extract  was  treated  as  before,  the  solution  some- 
what concentrated  and  potassa  added  ;  after  24  hours  the  crystals  of 
brucia  and  strychnia  were  collected  and  separated  by  repeated  washings 
with  warm  water.  On  concentrating  the  mother  lye,  a  further  crop 
of  crystals  was  obtained,  the  remaining  alkaloids  being  obtained  by  con- 
centrating the  mother  liquor,  treating  with  sulphuric  acid,  filtering 
from  resin,  and  again  precipitating  by  potassa.  The  small  amount 
of  alkaloids,  mainly  strychnia,  remaining  in  the  mother  waters  was  sep- 
arately estimated  by  the  test  solution. 
The  fluid  extract  of  stramonium  leaves  was  acidulated,  carefully  evap- 
orated, mixed  with  water,  filtered  from  resinous  matter,  and  diluted  to 
double  the  original  measure.  The  solution  being  too  dark  for  correct 
observations,  the  fluid  extract  was  precipitated  by  plumbic  acetate,  the 
precipitate  well  washed,  the  filtrate  freed  from  lead  by  hydrogen  sul- 
phide, and  the  filtrate  evaporated  to  three  times  the  original  bulk. 
Another  method  gave  the  same  quantitative  results.  The  alcohol 
was  evaporated  from  the  fluid  extract,  potassa  was  added,  and  the  liquid 
repeatedly  agitated  with  fresh  portions  of  chloroform  \  the  chloroformic 
solution  was  evaporated  in  contact  with  acidulated  water  and  filtered. 
The  same  processes  were  used  for  the  fluid  extracts  of  belladonna 
root,  belladonna  leaves  and  hyoscyamus. 
For  testing  the  fluid  extract  of  conium  fruit  it  was  found  necessary  to 
first  separate  resin  and  oil,  by  acidulating,  evaporating,  diluting  with 
water  and  filtering.    The  filtrate  was  now  concentrated,  and  the  conia 
