Am.  Jour.  Pharm.i 
August,  1S95.  j 
J  Tiburnu m  Prun ifoliti tn . 
389 
with  brown,  corky  warts.  Fracture  short  through  the  outer  layer ; 
the  inner  layer  tears  in  long,  fibrous  strips 
II.  Viburnum  prunifolium. — Trunk-bark  collected  by  Dr.  H.  H. 
Rusby,  at  Franklin,  N.  J.,  May,  1894.  Curved  pieces  and  fragments 
about  y§  inch  (4  mm.)  thick  ;  outer  surface  very  rough,  greenish  or 
grayish,  covered  here  and  there  with  gray  lichens;  inner  surface  yel- 
lowish-white, about  half  as  thick  as  the  corky  layer,  free  from  adhering 
wood;  the  cork  is  thick,  reddish,  and  shows,  on  a  cross-section,  small 
white  spots  dotted  throughout  its  tissue.    Fracture  short. 
III.  Viburnum  prunifolium. — Bark  collected  from  small  branches. 
Small  curved  pieces,  very  thin  ;  periderm  brownish-gray,  smooth, 
overlaying  a  green  chlorophyll  layer ;  inner  layer  whitish,  its  inner 
surface  yellowish-brown  from  exposure  to  air.  Fracture  short.  It 
seems  to  possess  the  bitter  principle  to  a  greater  extent  than  any 
of  the  preceding. 
IV.  Viburnum  prunifolium. — Bark  of  root  collected  at  Franklin, 
N.  J.,  May,  1894,  by  Dr.  H.  H.  Rusby.  Quills  or  fragments,  some- 
times with  strips  of  the  yellowish-white  wood  adhering  to  the  inner 
surface,  which  is  brownish  by  exposure  to  air.  The  corky  layer  is 
grayish-brown,  somewhat  ridged  so  as  to  form  more  or  less  distinct 
meshes.  The  inner  layer  is  thick,  breaking  with  a  short,  or  some- 
times waxy,  white  fracture,  easily  cut  or  scraped  with  the  finger- 
nail. 
V.  Bark  of  root  [source  unknown). — Flattish  or  curved  pieces, 
from  y&  to  yi  inch  (3  to  4  mm.)  in  thickness,  covered  by  (or  some- 
times deprived  of)  a  reddish  or  grayish-red  cork.  Inner  layer  of 
about  equal  thickness  to  the  outer,  breaking  with  a  short,  brownish- 
white  or  white  fracture. 
All  of  these  specimens  have  a  pronounced,  peculiar  odor,  difficult 
to  describe,  differing  quite  considerably  among  themselves  in  this 
respect.  The  root-bark  of  Viburnum  prunifolium  has  a  somewhat 
disagreeable  odor.  All  contain  a  bitter  principle,  this  bitterness 
being  particularly  prominent  in  the  root-bark  and  bark  of  small 
branches  of  V.  prunifolium.  In  the  trunk-bark  the  bitterness  is 
noticeably  less.  In  Viburnum  opulus  there  is  not  much  bitterness, 
but  there  is  quite  an  astringent  taste. 
STRUCTURAL  CHARACTERISTICS. 
A  cross-section  of  the  stem  bark  of  Viburnum  opulus  under  the 
microscope  shows  the  following  structure  :  Immediately  interior  to 
