Am.  Jour.  Pharm. ) 
August,  1914.  / 
Vleminckx's  Solution. 
355 
One  gramme  of  acetanilid  is  boiled  for  four  hours  with  a  mixture 
of  one  part  sulphuric  acid  (sp.  gr.  1.84)  and  five  parts  water.  The 
solution  is  then  cooled  and  carefully  neutralized  with  sodium  bicar- 
bonate. HQ  is  then  added  (6  mol.  to  1  mol.  anilin)  and  the  flask 
is  cooled  to  — io°  by  throwing  in  pieces  of  ice  and  using  a  freezing 
mixture.  The  sodium  nitrite  is  then  slowly  added  from  a  burette 
with  thorough  shaking  of  the  flask  after  each  addition.  From  time 
to  time  the  solution  is  tested  with  potassium  iodide-starch  paper.  It 
frequently  happens  that  the  potassium  iodide-starch  paper  turns  blue 
even  when  there  is  unchanged  aniline.  This  is  due  to  the  low  tem- 
perature, which  causes  the  diazotizing  to  take  place  slowly.  One 
must  therefore  not  be  too  hasty  in  his  conclusions,  especially  at  the 
end,  but  wait  several  minutes  after  the  addition  of  sodium  nitrite 
before  applying  the  Kl-starch  paper  test. 
As  mentioned  above,  Bay  and  Vignon,  the  originators  of  this 
method,  should  be  given  full  credit.  I  have  only  adapted  their  method 
of  determining  aniline  to  the  determination  of  acetanilid. 
PREPARATION  AND  ANALYSES1  OF  VLEMINCKX'S 
SOLUTION.1 
By  Joseph  L.  Mayer. 
A  short  time  ago  two  samples  of  Vleminckx's  Solution  were  sub- 
mitted to  me  with  a  request  that  in  view  of  the  fact  that  the  color  of 
one  sample  was  markedly  different  from  the  other,  analyses  be  made 
to  ascertain  if  they  were  properly  prepared. 
Since  the  National  Formulary  only  contains  a  formula  for  the 
preparation,  and  various  pharmaceutical  authorities  consulted  made 
no  reference  to  a  standard,  it  was  necessary  to  make  samples  in  an 
effort  to  determine  how  the  solution  should  be  prepared  and  what 
the  strength  of  the  finished  product  should  be.  The  following  work 
was  therefore  undertaken. 
Referring  to  page  81,  3rd  edition  of  the  National  Formulary, 
we  found  that  "  Liquor  Calcis  Sulphuratse  " — "  Vleminckx's  Solu- 
tion " — was  directed  to  be  prepared  as  follows : 
Lime,  freshly  slaked  165  grammes. 
Sublimed  sulphur  250  grammes. 
Water,  a  sufficient  quantity  to  make  1000  grammes. 
1  Read  before  the  Kings  County  Pharmaceutical  Society,  May  12,  1914. 
