Am.  Jour.  Pharm.  \ 
July  1,  1871.  J 
Suhnitrate  of  Bismuth. 
293 
muth,  which  remained  in  the  form  of  a  precipitate,  and  nitrate  and 
chloride  of  sodium,  which  went  into  solution  with  the  excess  of  carbon- 
ate of  soda.  The  carbonate  of  bismuth  being  collected  on  a  filter, 
washed  and  dried,  w^as  reduced  bj  ignition  to  the  oxide  of  bismuth 
and  weighed  as  such. 
To  the  filtrate  containing  the  carbonate  and  nitrate  of  soda  and 
chloride  of  sodium,  I  added  a  volumetric  solution  of  sulphuric  acid  to 
neutralize  the  carbonate  of  soda.  38*75  c.c.  volumetric  solution  of 
sulphuric  acid  neutralized  two  grammes  of  carbonate  of  soda,  there- 
fore 38*75  c.c.  acid  solution  contains  1*5094  grammes  of  anhydrous 
sulphuric  acid.  The  difference  then  between  the  amount  used  and 
the  amount  required  to  neutralize  two  grammes  of  carbonate  of  soda 
is  equal  to  the  nitric  acid  and  chlorine  in  combination  with  the  soda. 
I  then  dissolved  two  grammes  of  each  sample  of  suhnitrate  of  bis- 
muth in  hot  dilute  nitric  acid.  Three  of  the  samples  left  residues  of 
chloride  of  silver,  which  I  reduced  by  a  solution  of  caustic  soda,  and 
glucose  to  metallic  silver,  and  after  burning  and  careful  washing 
with  dilute  acetic  acid  to  remove  the  last  traces  of  soda,  and  burning 
again  I  weighed  it  as  metallic  silver.  To  the  filtrates  containing  the 
solutions  of  nitrate  of  bismuth  I  added  a  solution  of  nitrate  of  silver, 
which  gave  a  precipitate  in  two  of  the  samples,  in  the  other  two  only 
a  slight  turbidity.  The  precipitates  I  reduced  to  metallic  silver  as 
already  described,  ignited,  weighed  and  calculated  the  amount  of 
chlorine  from  that  of  the  silver.  I  then  tested  the  samples  in  Marsh's 
apparatus,  one  of  them  gave  metallic  spots,  which  I  tested  with  a  solu- 
tion of  hypochlorite  of  soda,  and  they  proved  to  be  Arsenic  by  their 
instantaneous  disappearance  when  touched  by  this  reagent. 
Afterwards  I  made  an  analysis  of  each  sample  in  the  following 
manner,  by  subjecting  the  four  samples  at  the  same  time  to  an  air  bath 
of  120°  C.  for  two  and  a  half  hours,  and  then  weighed,  the  loss  being 
the  amount  of  water,  then  ignited  and  weighed  again,  the  loss  this 
time  being  the  nitric  acid,  with  a  certain  amount  of  water  which  could 
not  be  driven  off  at  120°C.,  said  water  being  determined  by  deducting 
the  amount  of  nitric  acid,  etc.,  found  volumetrically.  The  amount  left 
after  driving  off  the  nitric  acid  and  water,  was  the  oxide  of  bismuth 
and  silver.  The  following  tables  show  the  results  of  my  labors,  which 
were  done  at  the  laboratory  of  Dr.  F.  A.  Genth,  to  whom  I  am  in- 
debted for  the  advice  given  and  the  interest  taken  in  my  labors. 
