^A$\iS%m'}      Analysis  of  Rhamnus  Purshiana.  167 
this  solution  being  precipitated  by  acids.  Concentrated  sulphuric  acid 
deepens  its  color  brownish-red.  It  is  not  removed  from  alcohol  solu- 
tion by  animal  charcoal.    In  the  bark,  it  resides  in  the  corky  layer  (a). 
III.  A  Light  Yellow  Resin  or  Neutral  Body,  tasteless,  colored 
bright  red-brown  by  sulphuric  acid,  not  colored  by  potassium  hydrate 
solution.  It  is  insoluble  in  water,  soluble  in  hot  alcohol,  sparingly  solu- 
ble in  cold  alcohol  of  seventy  per  cent.,  soluble  in  chloroform,  in  car- 
bon disulphide,  and  to  some  extent  in  benzol  (of  coal  tar).  In  the 
concentration  of  its  alcohol  solution,  it  deposits  in  pale  orange-yellow 
granules.  Its  alcohol  solution  gives  negative  results  with  the  general 
tests  for  alkaloids. 
IV.  A  Crystallizable  Body,  obtained  from  absolute  alcohol  solu- 
tion, in  white  double  pyramids  and  some  other  forms  of  the  dimetric 
system.  The  crystals  melt  and  then  sublime,  at  a  temperature  a  little 
above  the  water-bath,  the  sublimate  being  partly  crystalline.  This 
substance  is  not  appreciably  soluble  in  ether,  chloroform  or  petroleum 
ether  ;  is  slowly  soluble  in  absolute  alcohol,  slightly  soluble  in  seventy 
per  cent,  alcohol,  soluble  in  benzol  (of  coal  tar).  It  is  neutral  to  test 
papers,  and  is  not  dissolved  by  potassium  hydrate  solution,  by  acetic 
acid,  or  dilute  sulphuric  acid.  It  is  not  colored  by  potassium  hydrate 
solution,  concentrated  sulphuric  acid,  nitric  acid,  Froehde's  reagent,  or 
sulphuric  acid  followed  by  dichromate.  The  alcohol  solution  gives 
negative  results  with  the  general  tests  for  alkaloids.1 
V.  A  Tannic  Acid,  giving  brownish-green  color,  with  ferric  salts. 
VI.  Oxalic  Acid. 
VII.  Malic  Acid. 
VIII.  A  Fat  Oil,  of  yellow  color. 
IX.  A  Volatile  Oil,  not  abundant,  bearing  the  characteristic  odor 
of  the  bark. 
X.  Wax. 
XI.  Starch,  in  abundant  quantity. 
1  The  crystals  of  this  substance  were  repeatedly  obtained  as  follows  :  The  alco- 
hol extract  of  the  bark  (previously  exhausted  with  ether),  was  dissolved  by  water, 
this  solution  precipitated  by  lead  acetate,  the  washed  and  drained  precipitate  sus- 
pended in  absolute  alcohol  and.  the  lead  removed  by  hydrogen  sulphide,  and  the 
nitrate  then  evaporated.  A  distinct  alliaceous  odor  is  developed  after  the  hydrogen 
disappears,  and  the  crystals  in  question  then  appear.  The  crystalline  body  may 
prove  to  be  a  product  rather  than  an  educt,  and  its  production  may  be  related  to  that 
of  the  allyl  compound,  indicated  by  the  odor. 
