488 
mixture  and  this  assumption  was  confirmed  by  the  following  ex- 
periments. 
Five-tenths  of  a  gramme  of  eulatin  was  mixed  three  times  with 
10  c.c.  of  cold  water  and  after  standing  a  short  time  the  combined 
solutions  were  filtered.  In  the  faintly  violet  fluorescent  solution 
antipyrine  was  demonstrated  in  the  usual  manner;  on  the  other 
hand,  the  undissolved  residue  contained  no  antipyrine,  but  showed 
a  melting  point  of  251  °. 
Five-tenths  of  a  gramme  of  eulatin  was  treated  in  a  like  manner 
three  times  with  10  c.c.  cold  benzol;  the  undissolved  residue  was 
free  of  antipyrine  and  melted  at  251  °. 
It,  therefore,  became  necessary  to  identify  this  substance  with 
the  melting  point  of  251  °.  Literature  contains  not  less  than  six  iso- 
mers of  amidobrombenzoic  acid,  the  highest  melting  point  being 
225  °.  The  foregoing  substance  proved  to  be  soluble  in  and  lost 
its  acidity  in  sodium  carbonate  solution.  Several  grammes  of  finely 
powdered  eulatin  were  shaken  in  a  separatory  funnel  with  a  mixture 
of  chloroform  and  sodium  carbonate  solution  until  completely  dis- 
solved. The  lower  chloroformic  layer  was  drawn  off  and  the  alka- 
line solution  shaken  out  twice  again  with  chloroform.  The  com- 
bined chloroformic  solutions,  on  evaporation,  left  a  residue  of  pure 
antipyrine,  melting  point  I09°-iii°.  The  alkaline  solution  was 
treated  with  dilute  H2S04  to  liberate  the  acid,  which  was  recrystal- 
lized  from  toluol;  melting  point  25 1° -252 °. 
The  crystallized  substance  gave  a  negative  result  with  Las- 
saigne's  reagent,  showing  the  absence  of  nitrogen  and  therefore  of 
amidobrombenzoic  acid,  although  bromine  was  found  in  the  sub- 
stance. A  determination  for  bromine,  by  the  method  of  Carius,  of 
0.2690  Gm.  of  the  substance,  gave  the  following  result,  0.2520  Gm. 
AgBr  =  39.87  per  cent.  Br. 
Literature  records  a  brombenzoic  acid  with  a  melting  point  of 
25 1 0  known  as  p-brombenzoic  acid. 
A  mixture  of  the  acid  obtained  from  eulatin  and  pure  p-bromben- 
zoic acid  showed  a  melting  point  of  25 1°.  Besides  p-brombenzoic 
acid  eulatin  contained  still  another  acid. 
On  shaking  the  acid  filtrate  from  the  p-brombenzoic  acid  with 
ether,  a  nitrogen  body  (but  free  from  bromine),  acid-like  in  charac- 
ter, was  extracted.  It  had  a  melting  point  of  I44°-I45°  and  proved 
to  be  o-amidobenzoic  acid  (anthranilicacid) .  A  mixture  of  this 
with  pure  o-amidobenzoic  acid  showed  no  difference  in  melting 
point. 
