322  Study  of  Astragulus  Caryocarpus.  {Ami™y;w£T'n- 
was  again  dissolved  in  water  and  the  free  acid  removed  by  treating 
with  barium  hydroxide.  The  barium  sulphate  was  filtered  off  and 
the  excess  of  hydrate  removed  by  carbon  dioxide.  The  same  brown 
residue  was  obtained  on  evaporation.  It  was  evident,  therefore, 
that  the  substance  decomposed  by  simple  evaporation  on  a  water- 
bath.  This  residue  was  subsequently  examined  for  the  alkaloids, 
the  results  of  which  will  be  tabulated  later  on. 
From  the  repeated  processes  of  purification  given  above,  the 
amount  of  sugar  seemed  to  be  reduced  to  such  a  proportion  as  to 
make  it  undesirable  to  proceed  further.  Accordingly,  the  method 
was  tried  again,  with  larger  quantities,  modifying  so  as  to  remove 
completely  any  free  acid.  About  15  kilos  of  the  fruit  were  treated 
as  indicated  above,  except  that,  instead  of  basic  lead  acetate,  alumi- 
num hydroxide  was  used.  The  free  acid  was  removed  by  barium 
hydroxide.  The  solution  still  had  a  slight  color,  and  was  further 
purified  by  filtering  through  animal  charcoal.  This  practically 
clarified  the  solution.  A  small  quantity  was  evaporated  on  a  water- 
bath.  It  again  turned  brown.  The  remainder  of  the  solution  was 
set  aside  and  allowed  to  evaporate  spontaneously.  After  several 
days  the  solution  became  concentrated  enough  to  appear  syrupy. 
It  had  changed  slightly  in  color,  becoming  a  light  yellowish-brown. 
It  refused  to  crystallize  from  all  of  the  common  solvents.  From 
alcohol,  it  appeared  as  an  amorphous  powder ;  from  the  other  sol- 
vents, as  a  syrup.  This  syrup  was  later  obtained  as  a  solid  substance 
by  evaporating  in  a  vacuum  desiccator  over  sulphuric  acid.  After 
several  days'  drying  in  vacuum,  the  substance  became  a  solid  mass, 
which,  upon  rubbing,  became  a  light  gray  powder.  This  powder 
was  hygroscopic,  and  still  possessed  the  same  sweet  taste.  It  re- 
duced Fehling's  solution  and  turned  the  plane  of  polarization.  The 
specific  rotation  was  taken  after  the  substance  had  been  repurified 
twice  from  alcohol  and  animal  charcoal  and  dried  over  sulphuric 
acid.  The  substance,  thus  purified  and  dried,  had  a  specific  rotation 
(a)D  =  +  38-5.  The  melting  point  was  95°-g8°  C.  Analyses 
were  made,  the  results  of  which  corresponded  best  tor  the  ordinary 
disaccharide. 
THE  PHENYLHYDRAZONE. 
By  boiling  a  concentrated  solution  of  the  substance  with  phenyl- 
hydrazine,  a  well-defined  hydrazone  was  precipitated  from  the  solu 
