374 
Test  for  Alkaloids. 
f  Am.  Jour.  Pharmj. 
\     Aug.  1,  1874. 
color  to  brown  or  orange.  Sulphurous  acid  and  amnionic  sulphite- 
destroy  the  color  in  either  acid  or  alkaline  solution. 
Sodic  hyposulphite  does  not  completely  destroy  the  green,  but 
makes  it  paler,  and  on  the  addition  of  hydrochloric  acid  a  pale  bluisb 
green  remains,  which  is  unaltered  by  excess  of  acid,  but  gradually 
fades  away. 
Nascent  hydrogen  from  zinc  or  sodium  amalgam  rapidly  decolorizes 
the  acid  solution,  but  only  acts  very  slowly  on  the  alkaline  one.  No 
arsenetted  hydrogen  is  evolved.  The  green  matter  is  not  taken  up. 
from  its  aqueous  solution  by  ether,  bisulphide  of  carbon,  benzene,  or 
anilin,  but  is  partly  precipitated  by  alcohol. 
When  gallic  acid  is  present  in  excess,  a  green  solution  is  some- 
times formed,  which  is  not  reddened  by  acids,  but  only  turned  pur- 
plish, and  which  on  standing  deposits  a  bluish  precipitate. 
The  reaction  seems  peculiar  to  gallic  acid.  Gallotannic  acid  slowly 
gives  a  faint  greenish  tint,  probably  due  to  traces  of  gallic  acid,, 
while  pyrogallin  not  only  does  not  give  the  reaction,  but  seems  to- 
interfere  with  it  when  gallic  acid  is  present. — Jour.  Chem.  Soc.  (Lon^ 
don),  June,  1874. 
IODIDE    OF   BISMUTH    AND    POTASSIUM    AS    A    TEST  FOR* 
ALKALOIDS.* 
By  M.  Yvon. 
The  employment  of  the  double  iodide  of  bismuth  and  potassium 
has  been  indicated  for  the  detection  of  alkaloids,  but  the  value  of  this 
new  reagent  has  not  yet  been  sufficiently  established.  The  authorjT 
in  a  note  read  recently  before  the  Socie'te'  d'Emulation  pour  les. 
Sciences  Pharmaceutiques,  describes  a  method  for  its  ready  prepara- 
tion. 
The  preparation  of  the  reagent  by  means  of  iodide  of  bismuth,  ob- 
tained according  to  either  of  the  processes  given  in  Wurtz's  Diction- 
ary, and  iodide  of  potassium,  appears  to  present  some  difficulties,  the- 
iodide  of  bismuth  not  being  entirely  soluble  in  the  alkaline  iodide. 
But  it  is  not  at  all  necessary  to  use  the  iodide  of  bismuth,  and  thes 
*  Repertoire  de  Pharmacie,  vol.  ii,  p.  335. 
