404 
Rhamnus  Purshiana. 
l  Am.  Jour.  Pharm. 
\  September,  1914. 
H.  A.  D.  Jowett  ("  Proc.  of  the  Amer.  Pharm.  Assoc.,"  vol.  52, 
1904,  p.  295)  summarizes  the  results  of  previous  investigators  as 
follows : 
I.  The  only  definite  principle  isolated  from  cascara  bark,  the 
identity  of  which  can  be  considered  to  be  absolutely  established,  is 
emodin. 
2.  The  statement  of  the  existence  in  the  bark  of  chrysophanic  acid, 
chrysarobin,  or  glucosides  yielding  on  hydrolysis  emodin,  chryso- 
phanic acid,  or  rhamnetin,  is  not  supported  by  satisfactory  experi- 
mental evidence. 
Fig.  8. — Cutting  and  sacking  dried  Cascara  bark. 
3.  Wenzell's  "  crystals,"  Le  Prince's  "  Cascarine,"  and  Dohme 
and  Engelhardt's  "  Purshianin  "  would  appear,  from  the  descriptions 
given  by  the  respective  authors,  to  be  merely  impure  emodin. 
4.  No  indication  can  be  given  of  the  identity  of  the  crystals 
described  by  Prescott. 
5.  It  has  been  stated  by  Dohme  and  Engelhardt  that  the  fat  of 
cascara  consists  of  dodecyl  palmitate  and  stearate. 
Mr.  Jowett  ("  Proc.  Amer.  Pharm.  Assoc.,"  vol.  52,  1904, 
pp.  288-295),  in  his  investigations,  confirmed  the  presence  of  emodin 
in  cascara,  and  also  isolated  a  substance  which  he  called  isoemodin. 
He  also  found  glucose  and  syringic  acid.  No  evidence  was  obtained 
of  the  existence  of  chrysophanic  acid,  chrysarobin,  or  glucosides 
yielding  on  hydrolysis  emodin,  chrysophanic  acid,  or  rhamnetin. 
