402 
Rhamnus  Purshiana. 
(  Am.  Jour.  Pharm. 
(  September,  1914.. 
isolated  a  crystallizable  body  in  white  double  pyramids,  and  some 
other  form  of  dimetric  system.  Tannic  acid,  oxalic  acid,  malic  acid, 
a  fixed  oil,  a  volatile  oil,  wax,  and  starch  were  also  found.  (Amer. 
Jour,  of  Pharm.,  vol.  51,  1879,  P-  I^>5-) 
Limousin  (Jour,  de  Pharm.  et  de  Chim.  (5),  vol.  6,  1885,  p.  80; 
"  Proc.  of  the  Amer.  Pharm.  Assoc.,"  vol.  33,  1885,  p.  188)  con- 
sidered that  the  resins  obtained  by  Prescott  were  derived  from 
chrysophanic  acid,  which  he  believed  to  be  present  in  notable  quan- 
tities. According  to  H.  A.  D.  Jowett  ("  Proc.  of  the  Amer.  Pharm. 
Assoc.,"  vol.  52,  1904,  p.  288)  these  deductions  are  incorrect.  He 
believes  that  emodin,  which  he  claims  is  present,  will  give  the  char- 
acteristic reactions  thought  to  be  due  to  chrysophanic  acid. 
Fig.  7- — A  means  of  moving  dried  Cascara  bark  to  bark  cutter. 
W.  T.  Wenzell  (Pharm-.  Runds.,  vol.  4,  1886,  p.  79)  isolated  from 
the  bark  a  small  quantity  of  an  orange-red,  crystalline  substance, 
melting  at  226°-230°  C,  and  having  the  properties  of  a  glucoside. 
Later  investigators  have  shown  that  it  was  impure  emodin. 
H.  F.  Meier  and  J.  L.  Webber  (Amer.  Jour,  of  Pharm.,  vol.  60, 
1888,  p.  87)  found,  as  a  result  of  their  investigation,  a  glucoside,  a 
ferment,  glucose,  and  traces  of  ammonia. 
Paul  Schwabe  (Archiv,  der  Pharm.,  vol.  226,  1888,  p.  569)  ex- 
amined Rhamnus  Purshiana  and  found  emodin,  identical  with  that  of 
Rhamnus  frangula,  to  exist  as  such  in  the  bark,  and  identified  it  by 
means  of  its  acetyl  and  di-bromo  compounds,  all  of  which  were 
