508 
BARK  OF  MILLINGTONIA  HORTENSIS. 
chyma  is  irregularly  developed,  and  consists  of  three  or  four 
cells,  varying  between  the  hexagonal  tabular  and  rectangular 
prismatic  form,  and  with  the  wells  thicker  towards  the  corners. 
The  inner  parenchyma  is  composed  of  tangentially  arranged 
oval  cells,  frequently  separated  by  a  wall  of  later  growth  in  a 
radial  position,  the  cells  filled  with  chlorophyll. 
The  confines  of  the  primary  and  secondary  bark  are  marked 
by  larger  bundles  of  the  bast  cells.  The  whole  secondary  bark 
is  composed  of  two  kinds  of  cells,  with  thick  and  thin  walls,  in- 
terlined with  medullary  rays  and  alternating  with  each  other. 
The  thick-'walled  cells  are  prosenchymatous  and  have  but  little 
lumen  ;  they  are  surrounded  by  thin-walled,  short-celled  bast 
parenchyma,  and  interspersed  with  peculiar  shaped  cells,  con- 
taining starch.  All  parts  of  the  bark  with  the  exception  of  the 
starch  and  prosenchymatous  cells,  contain  short  prismatic 
crystals  of  oxalate  of  lime. 
QhemiQal  analysis  of  the  Bark. — The  ethereal  extract  was 
treated  with  water,  which  dissolved  a  little  of  a  neutral  bitter 
principle,  and  a  tannic  acid,  yielding  with  sesquisalts  of  iron  an 
olive  green  color ;  the  portion  left  undissolved  by  water  consisted 
chiefly  of  wax  with  traces  of  fixed  oil  and  some  olive  green 
coloring  matter. 
An  alcoholic  extract  was  prepared  from  the  bark  extracted 
by  ether,  and  treated  with  water  which  dissolved  sugar  ;  after 
destroying  it  by  fermentation,  the  liquid  left  on  evaporation  a 
brown,  shining,  brittle  mass,  which  the  author  considers  as  chiefly 
gum  or  dextrine.  The  portion  not  taken  up  by  water  was  a 
mixture  of  wax,  resin  and  coloring  matter,  probably  also  traces 
of  fat. 
Cold  water  now  dissolved  from  the  bark  a  minute  trace  of 
chlorophyll,  some  phosphoric  acid,  a  humic  acid  and  dextrine- 
like gum. 
The  bark  was  now  boiled  with  water,  and  the  decoction  fil- 
tered after  cooling.  The  filtrate  contained  phosphoric  acid, 
another  humic  acid,  sugar,  lime,  dextrine-like  gum,  and  some 
tannin. 
The  residuary  bark  yielded  to  diluted  hydrochloric  acid,  pec- 
tine,  and  oxalate  of  lime. 
The  aqueous  distillate  of  the  bark  was  found  to  be  free  of  any 
