392 
Viburnum  Prunifolium. 
(  Am.  Jour.  Pharm. 
\      August,  1895 
ten  times  as  long  as  thick.  The  component  cells  are  also  of  large 
size. 
The  clusters  of  stone  cells  occur  both  in  the  middle  and  in  the 
inner  layers  of  the  bark,  but  are  larger  in  the  latter. 
The  medullary  rays,  which  in  this  species  are  also'  straight  and 
composed  of  one  or  two  rows  of  cells,  are  much  less  easily  traceable 
than  in  the  former  species,  because  the  cells  differ  little  in  size  and 
shape  from  adjacent  parenchymatous  elements.  They  are  best 
recognized  by  means  of  iodine  solution,  their  cells  containing  more 
starch  than  those  of  adjacent  tissues. 
Freely  sprinkled  through  the  parenchymatous  regions  of  this 
bark  are  cells  containing  stellate  crystalline  masses  of  calcium  oxa- 
late,but  cells  containing  single  crystals  are  rare  or  wanting,  and 
there  is  no  crystal  sheath  about  the  masses  of  stone  cells. 
Tannin  is  also  present  in  this  bark,  but  apparently  somewhat  less 
abundant  than  in  the  former  species. 
The  bark  of  the  young  sterns  or  branches  differs  from  that  of  older 
ones,  in  the  fact  that  the  stone  cells  are  in  smaller  groups.  This  is 
because  in  the  old  bark  the  earlier  formed  masses  of  stone  cells 
have  been  cut  off  by  the  secondary  cork  formations,  and  the  later 
formed  groups  of  stone  cells  in  the  inner  layers  of  the  bark  are  of 
larger  size  than  the  older  ones  farther  exterior. 
The  bark  of  the  root  of  V.  prunifolium  differs  from  that  of  the 
stem  chiefly  in  the  fact  that  its  groups  of  stone  cells  are  farther 
apart  and  average  somewhat  larger  in  size.  The  outer  bark  is  also 
thicker  and  more  spongy  in  its  texture.1 
PHARMACEUTICAL  EXAMINATION. 
Five  grammes  of  each  of  the  powdered  drugs  were  taken,  and,  by 
means  of  the  continuous  extracting  apparatus,  chloroformic  extracts 
were  obtained.  The  amount  of  the  extractive  obtained  from  the 
tv/o  official  drugs  by  this  means  was  quite  different,  that  of  the  pru- 
nifolium being  nearly  twice  that  of  the  opulus.  The  physical  char- 
acteristics of  these  chloroformic  extracts  were  similar,  resin-like, 
yellow  to  green  in  color,  sticky  to  the  touch,  and  having  a  very 
1  It  appears  possible  to  distinguish  between  the  two  species,  V.  opulus  and 
V.  prunifolium,  by  the  presence  or  absence  of  stone  cells.  A  further  report  will 
be  made  on  this  point  when  some  experience  has  been  obtained  in  practically 
distinguishing  the  powders  of  the  two  species. 
