390  Acetanilid  in  Synthetical  Remedies.  {AmjSy,ri8^6arm" 
upon  the  formation  of  a  precipitate ;  one  depends  upon  the  genera- 
tion of  an  odorous  compound,  the  rest  upon  color  reactions.  Prefer- 
ence was  given  to  the  first  of  these,  because  when  published  by  E. 
Hirschsohn,  in  the  Pharm.  Ztschr.  f.  Russland,  it  was  offered  as  a 
means  of  detecting  5  per  cent,  acetanilid  in  phenacetin ;  therefore  it 
had  the  same  object  in  view  as  the  present  paper.  This  publication 
of  Hirschsohn  was  abstracted  in  the  Am.  Jour.  Pharm.,  1889,  77, 
as  follows  :  "  Antifebrin  in  phenacetin,  if  present  to  the  extent  of 
5  per  cent,  or  more,  can  be  readily  identified  by  making  a  satu- 
rated aqueous  solution,  and  adding  to  this  half  a  volume  of  bromine 
water.  Antifebrin  decolorizes  the  bromine  water  immediately,  and 
in  a  few  moments  a  crystalline  precipitate  appears.  Phenacetin 
neither  decolorizes  the  bromine  water,  nor  gives  the  precipitate, 
which  is  supposed  to  be  acet-para-bromanilide,  and  is  almost  insolu- 
ble in  water."  In  Dr.  B.  Fischer's  "  Die  Neuren  Arzneismittel," 
sixth  edition,  p.  177,  the  test  is  stated  as  follows :  "  If  01  gm.  phen- 
acetin be  dissolved  in  10  c.c.  hot  water  and  filtered  after  cooling  to 
the  temperature  of  the  room,  the  filtrate,  upon  addition  of  sufficient 
bromine  water  to  impart  a  yellow  color,  should  not  become  turbid. 
This  test  will  indicate  an  adulteration  with  acetanilid,  the  latter 
being  much  more  soluble  in  water  than  phenacetin,  and  therefore  is 
to  be  found  especially  in  the  filtrate,  giving,  with  bromine,  a  precipi- 
tate of  para-bromacetanilid  ;  allowed  to  stand  for  ten  minutes,  5  per 
cent,  of  acetanilid  can  be  detected  with  certainty."  This  test, 
according  to  B.  Fischer,  is  also  satisfactory  in  distinguishing  between 
acetanilid  and  methacetin,  the  latter,  in  saturated  aqueous  solution, 
not  giving  a  precipitate  with  bromine  water.  Fliickiger,  in  his 
"  Reactionen,"  states  that  phenocoll  hydrochlorate  in  aqueous  solu- 
tion gives  a  temporary  turbidity  with  bromine  water,  which  becomes 
more  permanent  with  a  large  excess  of  bromine  water.  These  are 
all  the  references  found  relating  to  this  test. 
For  the  following  experiments  I  per  cent,  solutions  of  exalgin  and 
phenocoll,  and  saturated  solutions  of  the  less  soluble  acetanilid, 
phenacetin,  methacetin,  lactophenin  and  salophen  were  used,  with  these 
preliminary  tests,  proved  that  a  decided  excess  of  bromine  water 
produced  precipitates  with  acetanilid,  lactophenin,  exalgin  and 
phenocoll,  and  a  decided  turbidity  with  methacetin  ;  in  the  last  three 
cases  a  distinct  turbidity  could  be  noticed  as  the  bromine  water  was 
allowed  to  drop  into  the  solutions,  disappearing  upon  agitation,  until 
