1 66  The  ApocynacecB  in  Materia  Medica.  ^Va^Tfi™' 
Beneath  this  the  layers  of  cells  pass  insensibly  into  the  fundamental 
parenchyma  formed  of  irregular,  sinuated  cells,  with  walls  irregu- 
larly thickened  and  elongated  in  the  direction  of  their  axes.  The 
limit  of  the  liber  portions  is  not  very  distinct.  The  medullary  rays 
traverse  the  parenchyma  in  a  sinuous  manner  and  are  formed  of  2 
or  3  rows  of  cells.  The  sclerotic  elements  are  numerous  and  scat- 
tered throughout  the  external  parenchyma  and  disappearing  almost 
entirely  in  the  liber.  The  laticiferous  vessels  on  transverse  section 
appear  like  the  other  cells  except  for  their  granular  contents;  on 
longitudinal  section,  they  appear  large  and  distinct. 
The  first  analysis  of  Dita  bark  appears  to  have  been  by  Gruppe, 
who  separated  a  bitter  non-crystallizable  substance,  which  he  named 
Ditaine.  Gorup  Besanez,  by  Stass'  method  separated  this  in  a  crys- 
tallized condition.  Hesse  and  Jbbst  succeeded  in  isolating  Ditamine, 
an  alkaloid,  and  a  closely  related  body,  Echitamine.  Harnack 
obtained  the  Ditamine  pure  by  crystallizing  from  ether  under  the 
name  of  Ditaine  crystallized,  and  concluded  that  this  was  the  only 
body  present.  Hesse,  as  a  result  of  a  later  complete  analysis^ 
described  the  following  constituents,  Echiceric  acid,  Ditamine  (alka- 
loid), Ditaine  or  Echitamine  (alkaloid),  Echicaoutchine  (amorphous 
resin),  Echiretine  (amorphous  neutral  body),  Echcerine,  Echitine, 
Echiteine  (non-crystallizable  bodies). 
Dita  bark  is  greatly  employed  as  an  antiperiodic  in  the  countries 
of  its  production,  where  it  is  even  claimed  to  be  superior  to  quinine 
and,  in  a  number  of  intestinal  disorders,  as  diarrhoea  and  dysentery, 
it  has  given  good  results.  It  is  recommended  in  debility  and  such 
fevers  as  typhoid  and  puerperal,  and  also  as  a  vermifuge.  It  is  a 
bitter  tonic,  stimulant  and  astringent.  The  powdered  bark  is 
administered  in  doses  of  -3  gm.  to  1  gm.,  frequently  associated  with 
ipecac  or  gentian.  The  10  per  cent,  tincture  is  used  in  doses  1  to  4 
gms. 
ALSTONIA  CONSTRICTA. 
The  Alstonia  constricta  F.  von  Mueller  (Tabeernoemontana  sp. 
Mitch.)  furnishes  the  Queensland  Fever-Bark  used  to  some  extent  in 
Europe.  The  bark  in  commerce  appears  to  be  from  branches  10  to 
12  cm.  in  diameter,  and  is  found  in  curved  pieces  varying  in  length 
from  20  to  30  cm.  and  about  12  cm.  wide.  The  thickness  varies  from 
7  m.m.  to  10  m.m.,  depending  upon  the  development  of  the  suber 
The  external  face  is  yellowish-gray,  marked  by  deep  fissures.  The 
