ON  METALLIC  BISMUTH.  167 
The  results  obtained  were  as  fo  ows  : — 
Sample  No.  1    .    .    .    .    0*12  per  cent. 
"     No.  2    ...    .  0-07 
"     No.  3    ...    .    0-05  " 
Liquor  bismuthi  prepared  from  the  worst  of  these  would  con- 
tain about  0-0018.  grain  of  copper  in  one  fluid-drachm  ;  that 
is  to  say,  less  than  the  y^f  ,  th  part  of  a  grain  in  a  dose.  Mr. 
W.  L.  Howie,*  in  a  paper  read  before  the  Glasgow  Chemists 
and  Druggists'  Association,  in  October,  1866,  stated  that  be 
found  the  quantity  of  copper  present  in  different  samples  of  bis- 
muthi to  vary  from  O-O-i  to  0-1  per  cent.  My  results  are  in  close 
accord  with  this  statement. 
The  fact  that  the  nitre  fusion  fails  to  remove  th^  <oppei'  con- 
stantly present  in  commercial  bismuth  has  been  the  chief  argu- 
ment employed  against  the  Pharmacopoeia  process  for  liq.  bis- 
muthi. When  it  is  seen  that  the  amount  of  copper  in  the  metal 
need  never  exceed  one  part  in  a  thousand,  and  will  generally 
be  much  less,  this  objection,  I  think,  loses  much  of  its  impor- 
tance. The  total  impurities  present  in  the  doubly  refined  bis- 
muth prepared  and  supplied  for  pharmaceutical  and  chemical 
purposes  by  Messrs.  Johnson  and  Matthey  are  stated  by  the  re- 
finers never  to  exceed  0-5  per  cent.,  and  frequently  to  amount 
to  not  more  than  0*3  per  cent.  I  venture  to  think  that  such 
metal  would  bear  comparison,  in  point  of  purity,  with  a  very 
large  number  of  chemical  products  now  used  in  medicine. 
But  although,  afc  the  present  day,  all  commercial  bismuth  con- 
tains an  appreciable  percentage  of  impurities,  that  is  so  only 
because  there  is  no  demand  for  a  purer  metal.  In  1865,  three 
years  ago,  Messrs.  Johnson  and  Matthey  exhibited  in  Dublin  a 
large  quantity  of  chemically  pure  bismuth.  This  metal  was  also 
shown  at  the  Paris  Exhibition  last  year.  It  can  be  produced 
in  any  quantity  when  required,  and  its  price  at  the  present  time 
is  40s.  per  lb.,  the  present  cost  of  the  commercial  metal  of  good 
quality  being  19s.,  and  that  of  the  double  refined  metal  already 
referred  to  22s.  A  sample  of  this  bismuth  was  kindly  lent 
to  me  by  Messrs.  Johnson  and  Matthey,  and  placed  upon  the 
Pharm.  Journ.,  vol.  viii,  p.  407. 
