AmjuOnUer,'i908arm'}     Chemical  Examination  of  Ipomcea  Purpurea.  257 
of  potassium  hydroxide,  the  alcohol  then  removed,  and  the  residual 
thick,  green  liquid  poured  into  a  large  volume  of  water.  The 
strongly  alkaline  liquid  was  extracted  six  times  with  ether,  the  com- 
bined ethereal  solutions  washed  with  water,  dried  with  calcium 
chloride,  and  the  ether  removed,  when  a  dark-colored  liquid  was 
obtained  which,  on  cooling,  solidified  to  a  crystalline  mass.  This 
was  dissolved  in  alcohol,  the  solution  heated  with  animal  charcoal, 
and  filtered,  when,  on  cooling,  a  quantity  of  a  solid  substance  sepa- 
rated, which  was  collected  on  a  filter  and  spread  on  a  porous  plate. 
After  being  again  subjected  to  the  same  process  of  purification,  it 
was  finally  distilled  under  a  pressure  of  15  m.m  ,  ween  it  was  obtained 
as  a  white,  silky  mass.  This  was  crystallized  from  ethyl  acetate, 
from  which  it  separated  in  small,  lustrous  leaflets,  melting  sharply 
at  74-750  C. 
0-0794  gave  0-2480  C02  and  01042  H20.    0  =  85-2;  H  =  14  6 
C35H72  requires  0  =  85-4;  H  =  14.6  per  cent. 
The  above  described  substance  was  thus  identified  as  pentatria- 
contane. 
The  alcoholic  mother-liquors  from  the  first  crys  tallization  of  the 
pentatriacontane  were  concentrated  and  allowed  to  stand,  when  a 
further  portion  of  a  solid  substance  separated.  This  was  collected, 
dried  on  a  porous  plate,  and  subsequently  crystallized  several  times 
from  a  mixture  of  ethyl  acetate  and  alcohol  containing  a  little  water. 
It  was  then  obtained  in  colorless  laminae,  melting  at  132-1330  C, 
and  afforded  the  color  reactions  characteristic  of  the  phytosterols. 
On  analysis  it  gave  the  following  results: 
0-1912  of  the  air-dried  substance  when  heated  to  105  0  C.  lost  0-0090. 
H20  =  4-7 
0-0682  of  anhydrous  substance  gave  0-2094  0O2  and  0-0722  H20 
0  =  837;  H  =  u-8 
C27H46  O,  H20  requires  H20  =  4-5  per  cent. 
C^H^O  requires  C  =  83  9 ;  H  =  1 1-9  per  cent. 
This  substance  was  thus  identified  as  a  phytosterol.    Its  optical 
rotatory  power  was  determined  with  the  following  result : — 
0-2336  of  anhydrous  substance,  dissolved  in  25  c.c.  of  chloroform, 
gave  aD  —  O- 360  in  a  2  dcm.  tube,  whence  [a]D  —  32-1°. 
From  the  character  of  this  phytosterol  it  would  appear  probable 
