INFLUENCE  OF  DRYING,  ETC. 
319 
placed  with  95  per  cent,  alcohol,  and  the  tincture  treated  like 
that  of  the  fresh  portion. 
The  other  half  of  the  fresh  plant  was  reduced  to  small  frag- 
ments, macerated  with  95  per  cent,  alcohol  for  24  hours,  then 
expressed  and  again  macerated  as  before.  The  liquids  were 
united,  filtered  and  distilled  at  a  temperature  of  56  to  60°C, 
the  residue  filtered  and  the  filtrate  evaporated  over  sulphuric 
acid  under  a  bell  glass ;  the  residue  upon  the  filter  was  kept 
separate. 
The  treatment  of  plants  containing  alkaloids  was  modified  by 
adding  tartaric  acid  to  the  tincture,  to  insure  the  solubility  of  the 
alkaloid  in  the  aqueous  solution  of  the  alcoholic  extract. 
Treatment  of  the  dry  extract.  1.  Plants  with  alkaloids.  The 
dry  extract  was  mixed  with  its  own  weight  of  burned  lime,  the 
mixture  treated  with  twice  the  weight  of  95  per  cent,  alcohol, 
and  after  24  hours  with  four  parts  of  ether,  well  agitated  and 
then  decanted  ;  the  sediment  was  twice  treated  in  the  same  man- 
ner. The  liquid  was  evaporated  spontaneously,  the  residue  dis- 
solved in  dilute  sulphuric  acid,  filtered,  precipitated  by  carbonate 
of  potassa  and  dissolved  by  absolute  alcohol. 
This  second  evaporation  usually  yielded  the  alkaloid  crystal- 
lized, particularly  from  the  fresh  plants.  In  the  case  of  liquid 
alkaloids,  caustic  instead  of  carbonate  of  potassa  was  taken,  and 
ether  in  place  of  alcohol ;  after  proving  its  identity,  the  quantity 
of  the  alkaloid  was  estimated  by  titration  with  oxalic  acid. 
The  comparative  treatment  of  plants  with  alkaloids  frequently 
gave  very  exact  results,  particularly  when  the  alkaloids  or  their 
salts  are  crystallizable ;  this  was  less  frequently  the  case  when 
the  plants  contained  no  alkaloids  and  the  active  principle  is  in- 
completely characterized. 
2.  Plants  without  alkaloids. — The  dry  extract  was  treated 
with  strong  ether,  and  the  filtrate  evaporated  spontaneously  ; 
the  undissolved  portion  was  treated  with  a  mixture  of  8  vol. 
strong  ether  and  2  vol.  95  per  cent,  alcohol,  and  the  filtrate 
evaporated  spontaneously.  The  residue  was  treated  with  cold 
distilled  water,  and  the  liquid  evaporated  over  sulphuric  acid. 
The  following  contains  the  results  obtained  by  the  author  with 
the  most  important  drugs. 
