266     Chemical  Examination  of  Ipomcea  Purpurea.  {AmjuTe?i908arm' 
of  this  oily  acid  was  converted  into  an  ammonium  salt,  from  which 
two  fractions  of  silver  salt  were  prepared  and  analyzed : 
(I)  0-1302  of  salt  gave  on  ignition  0-0490  Ag.    Ag  =  37  6 
(II)  0-1156"    "      "     "       "      0-0484  Ag.    Ag  =  419 
C8H1502  Ag  requires  Ag  =  43-0  per  cent. 
C10H19O2  Ag      "       Ag  =  38-7   <<  « 
The  acids  remaining  in  the  aqueous  distillate  after  extraction  with 
ether  were  converted  into  a  barium  salt,  of  which  about  8  grammes 
were  obtained.  This  afforded  reactions  which  established  the  pres- 
ence of  formic  and  butyric  acids.  After  drying  at  HO0  C,  it  was 
analyzed  with  the  following  result : 
0-5934  of  the  dried  salt  gave  0-5242  BaS04.    Ba  =  52  0 
(CH02)2   Ba  requires  Ba  =  60-4  per  cent. 
(C4H702)2  Ba      "      Ba  =  44-i    "  « 
This  salt  would  thus  appear  to  have  consisted  of  barium  formate 
and  butyrate  in  about  equal  proportions. 
The  liquid  remaining  in  the  distillation  flask  after  the  removal  ot 
the  volatile  acids  with  steam  was  separated  by  filtration  from  the 
resin  and  extracted  with  ether,  but  this  yielded  only  a  very  small 
amount  of  an  amorphous  substance  which  gave  a  green  coloration 
with  ferric  chloride. 
Treatment  zvith  Dilute  Alcoholic  Sulphuric  Acid. — Thirty  grammes 
of  the  resin  were  dissolved  in  alcohol,  and  such  an  amount  of  sulphuric 
acid  added,  with  a  little  water,  that  the  total  liquid  contained  about 
5  per  cent,  of  its  weight  of  acid.  After  heating  for  about  four  hours 
in  a  reflux  apparatus  the  alcohol  was  removed,  and  the  residue  dis- 
tilled witrrsteam.  The  distillate,  which  contained  some  oily  drops, 
was  extracted  with  ether,  the  ethereal  liquid  shaken  with  a  solution 
of  sodium  carbonate,  and  the  alkaline  liquid  separated.  After  the 
removal  of  the  ether  a  small  amount  (0-7  gramme)  of  an  aromatic, 
neutral  oil  was  obtained,  which  was  very  similar  in  character  to  that 
produced  under  the  same  conditions  from  the  ether  and  chloroform 
extracts  of  the  resin.  This  oil  was  distilled  under  a  pressure  of  40 
mm.,  when  it  passed  over  up  to  a  temperature  of  1700  C.  The  acid 
extracted  from  the  original  oily  liquid  by  means  of  sodium  carbonate 
was  obtained  as  a  yellow  oil  which  was  converted  into  an  ammo- 
nium salt,  and  from  the  latter  three  fractions  of  silver  salt  were  pre- 
pared and  analyzed. 
