262 
Hydrastine  Hexiodide. 
Am.  Jour.  Pharm. 
June,  1&99. 
These  statements  about  berberine  are  true  only  when  the  berber- 
ine  is  perfectly  pure,  such  as  can  be  obtained  from  berberine-acetone, 
according  to  the  directions  of  Gaze,1  and  dried  in  the  air  without 
heat.  Commercial  salts  of  berberine,  and  particularly  commercial 
berberine  itself,  is  generally  so  impure  that  some  of  these  reactions 
will  not  hold  good.2 
Basing  ourselves  upon  these  facts,  we  have  worked  out  a  method 
of  assaying  Hydrastis  canadensis,  the  plan  being  as  follows :  The 
alkaloids  of  the  powdered  root  are  first  set  free  by  the  action  of  an 
ethereo-ammoniacal  mixture  consisting  of  stronger  ammonia  water, 
5  c.c;  alcohol,  5  c.c.,  and  ether,  30  c.c.3  After  drying  the  powder  is 
extracted  with  absolute  ether,  and  the  ethereal  extract,  after  evapo- 
ration of  the  ether  and  taking  up  the  residue  with  acidulated  water, 
is  used  for  the  estimation  of  hydrastine  by  any  suitable  method. 
Through  the  powdered  root  left  in  the  extraction  apparatus  air  is 
passed  till  it  is  dry,  and  then  the  powder  is  extracted  with  alcohol 
to  exhaustion.  The  alcoholic  extract,  after  dilution  with  water, 
evaporation  of  the  alcohol  and  taking  up  the  residue  with  diluted 
acetic  acid,  is  used  for  the  estimation  of  berberine.  The  berberine 
is  first  precipitated  as  berberine  acetone,  the  latter  washed,  decom- 
posed by  the  aid  of  acid,  and  the  purified  berberine  estimated  by 
standard  solutions  of  potassium  iodide,  silver  nitrate  and  ammo- 
nium sulphocyanate. 
DIRECTIONS  FOR  THE  ASSAY. 
Ten  grammes  of  the  finely  powdered  hydrastis  are  rubbed  up  to 
a  paste  with  a  few  cubic  centimetres  of  the  above-mentioned  ethereo- 
ammoniacal  mixture  in  an  8-ounce  screw-top  ointment  jar,  and  a 
few  cubic  centimetres  more  of  the  same  mixture  are  then  added  so 
as  to  have  the  powder  well  covered  with  liquid.  The  small  pestle 
is  then  left  inside  and  the  jar  well  covered  is  set  aside  over  night. 
The  jar  is  then  opened,  put  into  a  good  current  of  air  till  the  odor 
1  The  compound  of  berberine  with  acetone  was  first  made  by  Gaze,  Arch.  d. 
Pharm.,  1890,  607. 
2  Loc  at. 
8  This  is  the  same  mixture  we  have  used  in  our  general  method  of  extracting 
alkaloids  (/.  Am.  Chem.  Soc,  1899,  232),  with  the  omission  of  chloroform. 
The  latter  gives  with  berberine  a  compound  not  decomposable  with  acids  (E. 
Schmidt,  Pharm.  Ztg.,  1889,  542). 
