418 
Gleanings -in  Materia  Medica. 
f  Am.  Jour.  Pharm*. 
(    August,  1883. 
defined  primary  membrane.  The  sieve  tubes  in  the  inner  layer  are- 
prominent  from  their  large  apertures,  and 
in  the  older  layers  appear  shrunken  in 
branching  cords  forming  the  so-called 
horn  bast.  The  joints  of  the  sieve  tubes 
are  about  '4  mm.  long  and  have  the  trans- 
verse membrane  horizontal,  coarsely  por- 
ous, and  mostly  covered  with  thick  callus. 
The  bark  is  free  from  starch. 
Zinc  chloride  with*iodine  imparts  a  vio- 
chewstick,  magnified  3  diam-     let  color  to  the  entire  primary  bast  fibres,. 
and  with  considerable  swelling  to  the  sec- 
ondary layers  of  the  secondary  bast  fibres  and  to  the  sieve-tube  walls. 
All  other  cell  membranes  are  colored  yellow,  and  the  contents  of  tan- 
gential groups  of  parenchyma  cells  in  the  soft  bast  brown.  These 
contents  are  insoluble  in  cold  water  and  potassa  solution,  almost  com- 
pletely soluble  in  boiling  water,  and  are  colored  black  by  ferric  salts. 
Other  parts  of  the  bark  are  free  from  tannin.  The  bast  parenchyma 
is  thin  walled ;  the  cells  of  the  medullary  rays  become  sclerotic  only 
in  old  stems. 
The  wood  is  in  circular  layers,  the  early  ducts  of  each  year  often- 
larger,  the  several  layers  varying  in  thickness,  occasionally  rather  com- 
pact, frequently  very  porous,  the  wood  cells  not  numerous.  The  ducts 
are  usually  imbedded  in  parenchyma,  appear  transversely  round  or 
roundish,  are  sometimes  '3  mm.  in  diameters  and  upon  the  walls  dotted. 
The  parenchyma  contains  rows  of  crystal  cells ;  the  pith  has  the  cell 
walls  somewhat  thickened  and  contains  scattered  crystals. 
The  bark  has  a  bitter  taste.  The  yellow  coloring  matter  is  con- 
tained in  the  membrane,  and  yields  with  hot  water  a  tasteless  solution 
which  does  not  react  with  ferric  chloride  or  alkalies. — Phar.  Central- 
halle,  1883,  No.  14. 
Catha  edulis,  Forskal,  natural  order  Celastracese,  is  a  shrub  about 
10  feet  high,  with  smooth,  elliptical,  serrate,  either  opposite  or  alter- 
nate leaves,  two  or  more  inches  long,  and  about  an  inch  wide.  It  is 
largely  cultivated  in  the  interior  of  Arabia,  and  furnishes  the  Jchat, 
cafta  or  Arabian  tea.  The  slender  twigs  with  the  leaves  attached  are 
gathered,  carefully  dried,  and  made  up  into  closely  pressed  bundles^ 
each  containing  about  40  twigs,  tied  together  by  strips  of  bark,  the 
quality  being  known  by  the  form  and  size  of  the  bundles.    The  use  of 
