262     Chemical  Examination  of  Ipomcea  Purpurea.     { ^m junUer."i908arm* 
The  aqueous  distillate  which  had  been  extracted  with  ether  still 
contained  a  small  amount  of  acid,  which  was  converted  into  a  barium 
salt,  and  this  yielded  reactions  indicating  the  presence  of  formic 
and  butyric  acids. 
After  the  removal  of  the  volatile  products  of  hydrolysis  by  dis- 
tillation with  steam  there  remained  in  the  distillation  flask  a  quantity 
of  greenish-black  resin  and  a  dark- colored,  aqueous  liquid,  which 
were  separated  by  filtration.  From  the  resinous  substance  nothing 
of  a  crystalline  nature  could  be  obtained.  The  acid,  aqueous  liquid 
was  first  extracted  with  ether,  which  removed  only  a  very  small 
quantity  of  a  syrupy  substance,  and  the  sulphuric  acid  then  removed 
by  means  of  baryta.  After  filtration  the  liquid  was  concentrated, 
when  about  3  grammes  of  a  syrup  were  obtained  which  instantly  re- 
duced Fehling's  solution  on  heating,  and  when  treated  with  phenyl- 
hydrazine  acetate  yielded  af-phenylglucosazone,  thus  indicating  the 
presence  of  glucose.  This  syrupy  liquid  also  contained  a  small 
amount  of  a  readily  soluble  organic  acid. 
III.  Chloroform  Extract  of  the  Resin. 
This  extract  formed  a  brown  mass,  which  could  readily  be  pow- 
dered. Its  solution  in  chloroform  was  first  repeatedly  extracted 
with  a  solution  of  sodium  carbonate,  but  this  removed  only  a  very 
small  amount  of  an  amorphous,  acidic  substance. 
Fusion  with  Potassium  Hydroxide. — Twenty  grammes  of  the  resin 
were  fused  with  120  grammes  of  potassium  hydroxide,  the  operation 
being  conducted  in  the  same  manner  as  has  been  described  in  con. 
nection  with  the  ether  extract.  The  cooled  mass,  when  dissolved 
in  water,  acidified  with  sulphuric  acid,  and  distilled  with  steam,  yielded 
a  small  amount  of  oily  acid.  This  was  extracted  with  ether,  con- 
verted into  an  ammonium  salt,  and  from  the  latter  three  fractions  of 
silver  salt  were  prepared  and  analyzed  : 
(I)  0-1364  of  salt  gave  on  ignition  00516  Ag.    Ag  =  37-8 
(11)0  0644       "  "  %\       00260  Ag.    Ag  =  40-4 
(III)o-0494       "  "  "       0  0206  Ag.    Ag  =  417 
C9H1702  Ag  requires  Ag  =  40  7  per  cent. 
CuH2102  Ag     <<        Ag  =  36  9  per  cent. 
The  volatile  acids  remaining  in  the  distillate  after  extraction  with 
ether  were  neutralized  with  baryta,  when  about  2  grammes  of  a 
