392  Acetanilid  in  Synthetical  Remedies.  {Amiu°iy%89h6arm" 
lutions  which  had  been  rendered  neutral,  acid  or  alkaline  without 
better  success,  the  test  was  finally  given  up  as  far  as  detecting  5  per 
cent,  acetanilid  in  phenacetin,  methacetin,  phenocoll  and  lactophenin, 
was  concerned. 
The  iso  nitrile  test,  depending  upon  the  formation  of  phenyl 
isocyanide  or  phenyl  carbylamine,C6H5NC,  by  heating  acetanilid  with 
solution  of  soda  or  potassa  and  a  few  drops  of  chloroform  or  a  little 
chloral  hydrate,  and  recognition  of  this  by  its  peculiar  and  offensive 
odor,  was  next  tried.  This  iso-nitrile  test,  it  must  be  remembered, 
is  a  class  reaction,  all  primary  amines  heated  with  alkali  and  chloro- 
form giving  rise  to  unpleasant  odors  due  to  the  formation  of  iso- 
cyanides;  its  application  for  the  purpose  in  view,  therefore,  resolved 
itself  mainly  into  a  question  of  determining  whether  the  remedies  other 
than  acetanilid  gave  rise  to  phenyl  isocyanide  or  to  some  other  body 
interfering  with  the  recognition  of  this.  Dr.  Fischer  states  that  the 
odor  is  furnished  by  acetanilid  and  phenacetin,  but  not  by  methace- 
tin or  exalgin  when  heated  for  a  short  time.  Fllickiger  states  that 
acetanilid  and  methacetin  yield  it ;  phenacetin  gives  rise  to  it,  or  at 
least  a  similar  odor;  exalgin  gives  a  different,  not  unpleasant,  odor. 
It  will  be  noticed  that  these  statements  are  to  a  certain  extent  at 
variance  with  each  other. 
Tests  were  made  by  using  2-3  c.c.  of  the  solutions  of  the  remedies 
as  made  for  the  bromine  test,  an  equal  volume  of  5  per  cent,  solu- 
tion of  potassa  was  added,  the  solution  heated  to  the  boiling  point, 
a  few  drops  of  chloroform  added,  boiled  again,  and  the  odor  noted 
after  the  excess  of  chloroform  had  evaporated.  Salophen  was  the 
only  one  to  yield  an  odorless  product;  the  other  tests  gave  rise  to 
odors  differing,  however,  from  that  of  phenol  isocyanide  as  obtained 
from  acetanilid.  The  delicacy  of  this  reaction  leaves  nothing  to  be 
desired,  as  it  was  obtainable  with  an  acetanilid  solution,  I  :  200,000, 
and  some  individuals  will  find  even  a  greater  dilution  satisfactory. 
Knowing  that  the  value  of  the  test  would  be  increased  if  it  were 
possible  to  remove  the  odors  due  to  the  other  remedies,  the  use  of 
potassium  permanganate  suggested  itself,  and  was-  successfully  used 
with  all  remedies  excepting  exalgin,  where  it  undoubtedly  caused 
the  formation  of  phenyl  isocyanide  instead  of  improving  the  test. 
Acetanilid  requires  the  use  of  but  little  permanganate  in  a  blank 
test,  and  this  did  not  interfere  with  the  delicacy  of  the  test ;  when, 
however,  considerable  permanganate  had  to  be  added,  it  was  found 
