258     Chemical  Examination  of  Ipomcea  Purpurea.  {Amju0nUer,'ifo8arm' 
that  it  is  identical  with  sitosterol  (compare  Chem.  Centralblatt,  1902 , 
Bd.  I,  p.  743,  and  1903,  Bd.  I,  p.  980). 
The  strongly  alkaline,  aqueous  liquid  resulting  from  the  hydrol- 
ysis of  the  petroleum  extract,  and  from  which  the  pentatriacontane 
and  phytosterol  had  been  extracted  by  means  of  ether,  was  concen- 
trated to  a  small  bulk,  acidified  with  sulphuric  acid,  and  distilled 
with  steam.  The  distillate  had  an  acid  reaction,  and  in  the  first 
portions  some  oily  drops  were  observed.  It  was  therefore  extracted 
with  ether,  the  ethereal  solution  being  washed  with  a  little  water, 
dried  with  calcium  chloride,  and  the  ether  removed,  when  a  small 
amount  of  a  pale-yellow,  oily  acid  was  obtained.  This  was  neutralized 
with  ammonia,  and,  by  fractional  precipitation  with  a  solution  of 
silver  nitrate,  several  silver  salts  were  prepared,  which  were  washed, 
dried  in  a  vacuum  over  sulphuric  acid,  and  analyzed. 
(I)  0  2004  of  salt  gave  on  ignition  0  0728  Ag.    Ag  =  36-3 
(II)  0.0760       "  "       "       0-0300  Ag.    Ag  =  39.5 
(III)ooii2       "  "       "       0-0046  Ag.    Ag  =  4i-i 
C9H17Oo  Ag  requires  Ag  =  40-8  per  cent. 
CnH2162  Ag     "       Ag  =  36  9   "  - 
The  results  of  these  analyses  indicate  the  volatile  oily  product 
to  be  a  somewhat  complex  mixture  of  acids,  and  no  conclusion  can 
be  drawn  respecting  the  identity  of  the  latter. 
The  aqueous  distillate,  after  extraction  with  ether,  still  contained 
a  small  amount  of  acid  which  was  converted  into  a  barium  salt. 
This  yielded  reactions  indicating  the  presence  ,of  both  formic  and 
butyric  acids. 
After  the  removal  of  the  volatile  acids  by  distillation  with  steam, 
the  contents  of  the  distillation  flask,  when  allowed  to  cool,  consisted 
of  a  yellowish  liquid,  on  the  surface  of  which  a  quantity  of  a  green 
solid  substance  had  separated.  This  was  removed,  dissolved  in 
ether,  and  the  ethereal  liquid  extracted  with  a  solution  of  sodium 
carbonate.  There  then  remained  in  the  ether  but  a  small  quantity 
of  substance  which,  when  purified,  was  obtained  in  the  form  of  color, 
less  crystals,  melting  at  74-75  0  C.  This  evidently  consisted  of  penta- 
triacontane, which  had  escaped  extraction  by  the  treatment  of  the 
alkaline  product  of  hydrolysis  with  ether.  The  sodium  carbonate 
extract  was  acidified,  when  a  green  product  was  precipitated,  which 
was  treated  with  light  petroleum,  a  small  amount  of  tarry  matter 
