324 
False  and  True  Senega. 
Am.  .Tonr.  Pliarsfi;. 
July,  1S81. 
was  evaporated  by  a  water-bath  to  tliree  fluidounces.  During  tJie- 
evaporation,  when  tlie  liquid  reached  the  temperature  of  158°F.,  it 
became  opaque,  and  at  167°F.  a  flocculent  precipitate  was  produced^ 
which  was  filtered  off,  and  it  appeared  to  be  albuminoid.  The  evap- 
orated liquid  was  repeatedly  shaken  Avith  fresh  portions  of  ether,  until 
the  latter  ceased  to  acquire  color.  This  required  fourteen  fluidounces. 
The  svrupy  liquid  remaining  was  mixed  with  twelve  fluidounces  oT 
alcohol,  and  four  fluidounces  of  ether  to  precipitate  the  polygalic  acid,, 
which  is  insoluble  in  this  menstruum.  The  precipitate  so  formed  was 
filtered  off,  and  j^roven  when  treated  with  Feh ling's  solution  to  be 
glucose,  the  polygalic  acid  remaining  in  solution. 
Another  portion  of  the  drug  was  treated  by  a  modification  of  Que- 
venne's  process ;  it  was  exhausted,  first  with  stronger  alcohol,  the  per- 
colate evaporated  to  three  fluidounces,  and  mixed  with  an  equal  bulk 
of  distilled  water ;  a  light  yellow  precipitate  of  a  resinous  character 
was  produced,  which  when  filtered  from  the  solution  was  found  to  be 
solul)le  in  ether,  stronger  alcohol  and  solution  of  potassa.  The  remain- 
ing liquid  was  treated  with  solution  of  basic  acetate  of  lead  until  a 
precipitate  ceased  to  be  produced;  the  precipitate  so  formed  was  fil- 
tered off,  suspended  in  distilled  water,  and  decomposed  by  hydro-sul- 
phuric acid  ;  the  filtered  liquid  was  evaporated  by  means  of  a  water- 
bath,  when  the  polygalic  acid  remained  as  a  brownish  powder ;  it  was 
then  well  shaken  with  ether,  to  remove  adhering  coloring  matter ;  the 
ether  was  decanted,  leaving  the  polygalic  acid  as  an  amorphous  light 
yellowish  ])owder.  The  amount  of  acid  thus  obtained  w^as  two  per 
cent.  . 
The  remaining  drug  was  now  treated  with  dilute  alcohol  until  two- 
pints  had  passed ;  this  was  evaporated  to  four  fluidounces,  precipitated 
with  solution  of  basic  acetate  of  lead,  the  precipitate  filtered  off,  sus- 
pended in  water  and  decomposed  by  sulphuretted  hydrogen,^  and  the 
filtered  liquid  evaporated  to  dryness,  leaving  polygalic  acid  to  the 
extent  of  one  per  ceiit.,  making  a  total  of  three  per  cent,  of  polygalic 
acid  in  this  false  senega. 
Procter's  process,  when  applied  to  true  senega,  yielded  five  per  cent, 
of  acid,  while  Quevenne's  process  gave  five  and  a  quarter  per  cent. 
Procter's  process,  being  less  comj^licated,  is  preferable  for  the  manu- 
facture of  polygalic  acid  from  true  senega. 
1  The  sulphide  of  lead  is  stated  by  Quevenne  to  retain  a  portion  of  the' 
polygalic  acid,  and  on  that  account  requires  to  be  treated  with  hot  alcohoL 
— Editok. 
