THE  AMERICAN 
JOURNAL  OF  PHARMACY 
MAY,  1896. 
HOW  TO  DISTINGUISH  THE  VIBURNUM  BARKS 
IN  THE  STATE  OF  POWDER. 
By  L.  E.  Sayre, 
Member  of  Research  Committee  C,  of  the  Committee  on  Revision  of  the 
United  States  Pharmacopoeia. 
In  a  paper  communicated  to  this  journal  a  few  months  ago,1  the 
writer  discussed  certain  physical  characteristics  of  the  Viburnum 
barks,  with  a  view  to  their  identification  in  the  state  of  powder.  The 
problem  presented  to  the  Research  Committee,  with  reference  to  the 
subject,  was  formulated  as  follows  : 
(1)  What  are  the  distinguishing  characteristics  which  will  identify 
the  bark  of  the  stem  and  the  bark  of  the  root  of  Viburnum  pruni- 
folium  ? 
(2)  How  can  one  distinguish  between  the  bark  of  Viburnum 
prunifolium  and  V.  opulus  ? 
(3)  What  are  the  differential  characteristics  of  these  barks  which 
will  enable  one  to  distinguish  between  them  in  the  crushed  or  pow- 
dered condition  ? 
The  first  and  second  of  these  problems  were  discussed  in  the 
former  paper,  the  third  was  left  for  a  future  one.  Cross-sections  of 
the  stem  bark  of  V.  opulus  and  of  the  bark  of  the  root  of  V.  pruni- 
folium, as  seen  under  the  microscope,  were  then  presented,  and  are 
reproduced  now  (see  Figs.  1  to  /f).  It  was  shown  in  the  case  of  V. 
opulus  that  in  the  inner  layer  of  the  bark  there  were  large  clusters, 
in  the  form  of  elongated  bands,  of  bast  fibres,  associated  with  but  few 
1  Amer.  Jour.  Pharm:,  gt,  387. 
(225) 
