168  ON  METALLIC  BISMUTH. 
table  at  the  last  Pharmaceutical  Meeting.  No  doubt  the  com- 
paratively high  price  of  this  pure  metal  has  hitherto  prevented 
its  use  in  pharmacy. 
Mr  tson  said  he  had  found  the  same  difBculty  in  the  metallic  bis- 
muth of  commerce  that  Mr.  Wood  had  ;  namely,  that  of  getting  rid  of 
all  traces  of  copper.  There  were  many  different  qualities  of  commercial 
bismuth  in  the  market,  but  he  had  generally  found  that  if  they  could 
only  procure  Saxony  bismuth,  it  contained  as  little  as  0*001  of  copper 
ard  no  arsenic  ;  whereas  the  qualities  generally  met  with  contained 
0  004  or  0"5  per  cent.  The  bismuth  that  had  been  imported  from  Aus- 
tralia lately  contained  a  much  larger  proportion  of  copper,  and  also 
traces  of  arsenic.  He  had  frequently  tried  bismuth  by  fusion  with  nitre, 
but  could  not  get  rid  of  the  last  traces  of  copper. 
Dr.  Attfield  thought  too  much  had  been  made  of  the  presence  of  a 
trace  of  copper  in  bismuth,  and  too  little  of  other  impurities  which  were  col- 
orless. He  should  like  to  ask  Mr.  Wood  whether  his  one  part  of  copper  in 
one  thousand  of  bismuth  gave  much  of  a  blue  color  to  the  liquor,  say,  when 
ihey  were  looking  at  a  Winchester  quart ;  and  he  should  like  to  ask  Mr, 
Watson  what  sort  of  a  result,  so  far  as  the  eye  was  concerned,  he  got 
with  bismuth  containing  l-10,000th  part  of  copper  ?  Chemists  and  drug- 
gists generally,  he  feared,  depended  too  much  on  the  eye  and  too  little 
on  the  test-tube 
The  President  remarked  that  there  whs  another  point  of  view  in  which 
he  suspected  they  looked  at  it,  and  that  was  the  cost.  If  it  became  a 
question  simply  of  purity,  there  was  not  the  slightest  difficulty  ;  but  it 
was  a  question  of  cost.  There  had  been  imported  into  this  country  large 
quantities  of  bismuth  from  Australia  and  Peru,  and  many  of  these  speci- 
mens of  metal  were  certainly  very  impure  ;  but  there  is  one  process  which 
had  been  found  to  succeed,  and  that  was  at  once  to  crystallize  out  the 
nitrate  of  bismuth,  and  by  operating  upon  that  they  would  get  j,  bismuth 
which  would  be  tolerably  pure,  the  impurities  remaining  in  the  mother 
liquor  almost  entirely.  That,  however,  was  a  long  process,  and  they  could 
do  it  with  the  other  process  quite  well  enough  for  medicinal  purposes. 
Dr.  Redwood  mentioned  that  there  was  not  so  much  bismuth  produced 
in  Saxony  now  as  formerly,  the  mines  not  being  so  fully  worked  as  they 
used  to  be. 
Mr.  Watson,  in  reply  to  Dr.  Attfield's  question  as  regarded  the  color 
inseparable  from  the  solution  made  by  the  best  Saxon  bismuth,  said  he 
found  they  could  trace  it  clearly  by  the  eye  by  adding  a  few  drops  of 
ammonia.  He  remembered  some  few  months  ago  sending  out  some  bis- 
muth to  a  provincial  chemist,  containing,  he  believed,  not  more  than  0'05 
of  copper,  and  it  was  returned  to  them. 
