406       NEW  ADULTERATION  OF  SUBNITRATE  OF  BISMUTH. 
With  reference  to  Liquor  Bismuthi  et  Ammonice  Citratis,  on 
which  there  has  been  some  correspondence  in  this  Journal,  it 
may  be  stated  that,  if  the  conditions  specified  in  the  Pharmaco- 
poeia be  fulfilled,  that  is  to  say,  if  the  bismuth  employed  has  been 
purified  in  the  manner  described,  and  if  the  purified  metal,  and 
also  the  solution  prepared  from  it,  answer  to  the  tests  as  given, 
the  latter  will  be  free  from  arsenic,  lead,  copper  and  silver.  These 
are  the  impurities  most  likely  to  occur,  and  to  the  removal  or 
detection  of  which  the  process  of  purification  and  the  tests  of  the 
Pharmacopoeia  are  directed  ;  but  if  it  were  the  object  of  a  manu- 
facturer to  introduce  other  impurities  which  would  elude  detection 
by  the  tests  as  given,  it  would  no  doubt  be  possible  to  do  so.  I 
have  recently  met  with  two  instances  of  such  adulteration  in  sub- 
nitrate  of  bismuth,  an  account  of  which  will  be  found  in  the  fol- 
lowing article. — Lond.  Pharm.  Jo  urn.,  August,  1868. 
NOTE  ON  A  NEW  ADULTERATION  OP  SUBNITRATE  OF 
BISMUTH. 
By  Dr.  Redwood. 
I  have  recently  had  occasion  to  examine  two  samples  of  sub- 
nitrate  of  bismuth,  which  have  proved  to  be  adulterated  to  a 
great  extent,  by  the  admixture  of  a  substance  which  noue  of  the 
tests  usually  applied  would  detect.  These  samples  were  sent  for 
examination  by  wholesale  druggists  who  had  been  led  to  suspect 
that  they  were  not  genuine,  but  who  were  greatly  surprised  to 
learn  the  extent  and  nature  of  the  adulteration. 
The  first  of  the  samples  was  sent  me  last  May.  It  presented 
the  usual  appearance  of  the  variety  of  subnitrate  of  bismuth 
generally  met  with  in  commerce  in  the  form  of  powder,  without 
any  crystalline  character.  It  dissolved  in  nitric  acid  with  a 
slight  evolution  of  carbonic  acid  gas,  and  this  had  caused  it  to 
be  condemned  as  impure,  by  a  customer  to  whom  it  had  been 
sent.  The  quantity  of  carbonate  present  in  it  was,  however,  ex- 
tremely small.  In  other  respects  it  answered  to  the  Pharmaco- 
poeia tests,  excepting  that  the  solution  in  nitric  acid  gave  a  pre- 
cipitate with  nitrate  of  silver,  indicating  the  presence  of  oxy- 
