344 
Determination  of  Bismuth. 
Am.  Jour.  Pharm. 
May,  1921. 
out  the  land  as  is  given  to  medical  education  and  that  they  should 
be  encouraged  and  aided  in  their  laudable  ambition  to  raise  the  edu- 
cational standards  and  maintain  this  important  calling  at  a  point 
where  it  merits  the  dignity  of  a  profession,  the  profession  without 
whose  intelligent  service  the  practice  of  medicine  would  be  hampered 
and  its  development  retarded. 
"Pharmacy  is  an  art  and  a  science.  It  can  never  be  less ;  it 
should  be  more." 
DETERMINATION  OF  BISMUTH  BY  FORMALDEHYDE* 
By  S.  B.  Tallantyre. 
The  need  for  a  rapid  method  of  estimating  bismuth  in  medicinal 
compounds  suggested  to  the  author  of  calling  attention  to  the  appli- 
cability of  the  formaldehyde  reduction  process.  The  details  of  the 
method  are  as  follows : 
The  compound  or  preparation  is  warmed  with  a  small  quantity 
of  dilute  hydrochloric  acid  (about  10  per  cent.)  for  a  few  minutes 
until  it  is  decomposed  and  all  the  bismuth  is  in  solution.  The  mix- 
ture can  then  usually  be  treated  at  once  with  a  fair  amount  of  formal- 
dehyde solution,  then  a  good  excess  of  10  per  cent,  sodium  hydroxide, 
warmed  and  finally  boiled  until  the  precipitate  of  bismuth  all  sepa- 
rates to  the  bottom  of  the  solution.  The  supernatant  liquid  is  now 
treated  with  more  of  the  reagents  and  the  whole  again  heated  to  boil- 
ing to  make  sure  reduction  is  complete.  The  clear  liquid  can  then  be 
decanted  or  filtered  off  and  the  bismuth  either  washed  by  decanta- 
tion  with  hot,  weak  formaldehyde  water,  or  if  it  is  not  in  a  well- 
coagulated  condition,  reboiled  with  a  little  more  formaldehyde  and 
sodium  hydroxide  solutions.  By  stirring  or  pressing  the  bismuth  col- 
lects into  a  spongy  mass  which  is  very  easily  removed  to  a  tared 
filter,  Gooch  crucible,  or  weighing  bottle,  washed  with  absolute  alco- 
hol, and  weighed  after  drying  an  hour  or  so  at  1050  C. 
The  precipitate  is  pure  bismuth  produced  according  to  the  fol- 
lowing reaction: 
2Bi(OH)3+3H.CHO+3NaOH=2Bi+3HCO-ONa+6H20. 
^Chemist  and  Druggist,  through  Merck's  Report,  April,  1921. 
