1 72  The  A pocynacece  in  Materia  Medica.   { ^i?!*,  £95 rm' 
The  drug  is  constituted  of  fragments  of  wood  obtained  from  the 
stem,  but  the  root  is  equally  active.  They  attain  3  to  5  cm.  in 
diameter.  The  bark  is  1  to  1-5  mm.  thick,  greyish  yellow  in  color 
with  silvery  appearance  in  spots.  It  adheres  closely  to  the  wood, 
but  the  suber  can  be  easily  scratched  off.  Externally  it  is  longitu- 
dinally ridged  and  somewhat  scaly.  The  fracture  is  brownish,  taste 
is  peculiar  and  persistent. 
The  wood  is  very  hard  and  compact,  yielding  a  clear,  bright  sec- 
tion without  pores ;  the  concentric  zones  scarcely  visible  ;  the  pith 
is  very  small  quadrangular  and  eccentric.  The  color  is  a  pale  yel- 
low and  clear  on  fresh  section,  deeper  ochre-yellow  on  old  surfaces, 
and  quite  dense,  odorless  and  having  very  little  taste.  Ligneous 
fibres  very  abundant ;  the  vessels  are  relatively  few  in  number  and 
quite  small.  The  medullary  rays  consist  of  one  or  two  rows  of 
cells  which  frequently  contain  crystals  of  calcium  oxalate.  The  de- 
coction of  the  wood  yields  a  green  coloration  after  twelve  to  forty- 
eight  hours,  which  lasts  for  several  days.  A  green  fluorescence  is 
also  produced  by  sulphuric  acid  in  either  solutions  of  ouabaine  or 
in  decoctions  of  the  wood. 
Arnaud,  in  1888,  separated  a  white  crystallized  glucoside,  the 
Ouabaine,  which  is  inodorous  and  not  bitter,  or  but  very  slightly  so 
in  comparison  with  the  wood.  Its  formula  differs  from  that  of  Stro- 
phanthine by  CH2.  It  has  been  found  by  the  same  chemist  in  the 
Strophanthus  glaber  of  Gaboon.  The  wood  and  the  root  contain 
about  3  parts  in  1,000. 
Lewin  has  separated  from  A.  Schimperi  A.  DC.  a  product  different 
from  the  Ouabaine  of  Arnaud,  which  he  named  ajnorphous  Ouabaine. 
He  likewise  separated  an  oily  substance  readily  solidified  Carissol. 
From  the  bark  he  separated  impure  Ouabaine,  and  a  very  bitter, 
non-poisonous  substance  Carissine. 
The  toxicity  of  the  wood  of  the  Ouabaia  is  demonstrated  by 
usage  to  be  the  same  as  that  of  the  arrow  poison.  For  the  latter 
purpose  the  aqueous  extract  is  made  into  balls,  and  a  small  amount 
is  spread  on  the  extremity  of  the  arrows  ;  5  to  10  m.gm.  being  suf- 
ficient to  kill  a  rabbit.  The  physiological  action  seems  to  be  simi- 
lar to  that  of  Strophanthine,  only  many  times  stronger.  On  the  con- 
junctiva of  animals  it  produces  anaesthesia,  but  according  to  Panas 
it  is  inactive  upon  the  human.  According  to  Lewin  this  anaesthe- 
sia of  the  cornea  is  much  slower  but  more  perfect  and  durable  than 
