LIQUOR  BISMUTHI  ET  AMMONIiE  CITRATIS. 
261 
ON  LIQUOR  BISMUTHI  ET  AMMONIA  CITRATIS. 
By  C.  H.  Wood,  F.C.S. 
Through  the  medium  of  the  advertisement  columns  of  the 
medical  journals  Mr.  Schacht,  of  Clifton,  has  recently  cast  some 
disparagement  on  the  Liquor  bismuthi  et  ammonise  citratis  of 
the  new  British  Pharmacopoeia.  As  this  preparation  is  obviously 
intended  to  represent  the  very  elegant  solution  of  bismuth  intro- 
duced into  pharmacy  a  few  years  back  by  Mr.  Schacht  himself, 
it  becomes  a  matter  of  some  interest  to  determine  the  justice  of 
Mr.  Schacht's  remarks  upon  it.  ^tnougn  Mr.  Schacht's  process 
has  not  been  published,  analysis  has  shown  that  the  original 
"  Liq.  Bismuthi"  contains  an  ammonio-citrate  of  bismuth,  and 
several  methods  have  been  proposed  for  producing  this  com- 
pound. But  most  of  these  have  been  somewhat  complicated  and 
troublesome. 
The  process  given  in  the  Pharmacopoeia  possesses  two"  great 
advantages.  It  is  extremely  simple  and  easy'of  execution,  and 
it  furnishes  a  liquor  of  perfectly  uniform  and  definite  strength. 
Assuming  the  materials  employed  to  be  pure,  it  yields  a  solution 
of  ammonio-citrate  of  bismuth  containing  only  nitrate  of  ammo- 
nia in  addition.  We  may  fairly  suppose  that  the  authors  of  the 
Pharmacopoeia  considered  this  latter  salt  to  be  a  harmless  con- 
stituent of  the  solution,  pr  they  would  have  taken  means  to  ex- 
clude it. 
In  the  advertisements  I  have  referred  to,  however,  it  is  alleged 
that  the  Pharmacopoeia  preparation  will  contain,  in  addition  to 
the  nitrate  of  ammonia,  "  almost  invariably  arsenic  and  cop- 
per, and  frequently  antimony,  etc."  These,  it  is  stated,  will  be 
derived  from  the  impurities  notoriously  prevalent  in  metallic 
bismuth. 
It  must  be  admitted  that  the  presence  of  these  metals  in  vary- 
ing proportions  would  detract  from  the  value  of  the  Pharmaco- 
poeia solution,  and  constitute  an  objection  to  the*  officinal  process. 
Having  prepared  several  samples  of  this  liquor,  operating  strict- 
ly according  to  the  instructions  of  the  Pharmacopoeia,  I  thought 
it  desirable  to  examine  them  carefully  for  these  metallic  impuri- 
ties.   When  the  liquor  was  prepared  from  metallic  bismuth,  pu~ 
