264     Chemical  Examination  of  Ipomcea  Purpurea.  {Amjine?i908arm* 
quantity  of  resinous  substance  and  an  aqueous  liquid.  The  latter, 
alter  the  removal  of  the  sulphuric  acid,  yielded  about  1*5  grammes 
of  a  syrup  in  which,  by  the  formation  of  ^.phenylglucosazone, 
the  presence  of  glucose  was  determined.  This  syrupy  liquid  also 
contained  a  small  amount  of  a  readily  soluble  organic  acid. 
From  these  results  it  will  be  seen  that  the  chloroform  extract  of 
the  resin,  by  treatment  with  dilute  sulphuric  acid,  yielded  products 
very  similar  in  character  to  those  obtained  from  the  ether  extract. 
IV.  Ethyl  Acetate  Extract  of  the  Resin. 
This  extract,  as  originally  obtained,  was  allowed  to  stand  for  some 
time  without  removing  the  solvent,  when  it  deposited  a  considerable 
quantity  of  a  brown,  viscid  resin,  together  with  a  small  amount  of 
a  slightly  colored,  flocculent  substance.  The  ethyl  acetate  liquid 
was  decanted  from  these  products,  which  were  then  treated  with 
alcohol,  when  most  of  the  flocculent  substance  remained  undissolved, 
and  was  separated  by  filtration.  The  alcoholic  filtrate,  after  being 
boiled  with  animal  charcoal  and  again  filtered,  was  concentrated  to 
a  small  bulk,  when  a  little  more  of  the  flocculent  substance  was 
obtained.  The  ethyl  acetate  liquid,  which  had  been  decanted  from 
the  above-mentioned  products,  was  concentrated,  when  a  further  small 
amount  of  the  flocculent  substance  separated,  and  was  removed  by 
filtration.  This  filtrate  was  finally  mixed  with  the  alcoholic  solution 
of  the  viscid  resin  and  the  solvents  removed,  the  residual  product 
thus  representing  the  total  resin  extracted  by  ethyl  acetate,  deprived 
so  far  as  possible  of  the  small  amount  of  light  colored,  flocculent 
solid. 
Isolation  of  a  New  Dihydric  Alcohol,  Ipuranol,  C^HggO^OH)^ 
The  several  portions  of  flocculent  solid  described  above  were 
mixed,  dissolved  in  alcohol,  and  the  solution  boiled  with  animal 
charcoal.  After  filtering,  and  concentrating  the  liquid,  the  substance 
separated  in  a  perfectly  white  condition.  The  amount  obtained  was 
only  about  0  2  gramme.  When  heated  on  platinum-foil  it  first  charred, 
and  then  burned  with  a  smoky  flame,  leaving  finally  no  residue.  It 
was  very  sparingly  soluble  in  alcohol  or  ethyl  acetate,  and  quite 
insoluble  in  water,  even  when  hot.  Its  alcoholic  solution  was  neutral 
to  litmus.  The  substance  was  not  decomposed  by  dilute  acids  or 
alkalis,  even  on  boiling.    It  was  found  to  be  freely  soluble  in  pyri- 
