222 
Characteristics  of  Vegetable  Fibres. 
J"  Am.  Join-.  Pharm. 
t       April,  1884. 
MICROSCOPICAL  CHARACTERISTICS  OF  VEGETABLE 
FIBRES. 
In  a  paper  on  this  subject  in  the  "  Zeitschrift  fur  Warenkunde,"  Dr.  V. 
Bert  hold  classifies  the  more  important  vegetable  fibres,  according  to  the 
action  upon  them  of  iodine  and  sulphuric  acid,  as  follows  : 
A.  Colored  blue,  violet,  or  green  by  iodine  and  sulphuric  acid:  Flax, 
Chinese  grass  and  ramie  (Boehmeria  nivea),  roa  {Pipturus  argenteus), 
cotton,  hemp  and  sunn-hemp  (Crotalaria  juncea). 
I.  Transverse  sections  colored  blue  or  violet,  but  showing  no  yellow  mid- 
dle lamella  ;  cell-cavity  usually  filled  with  a  yellow  mass. 
a.  Flax. — Transverse  sections  occur  either  isolated  or  a  small  number 
grouped  together ;  the  separate  transverse  sections  are  not  contiguous  ; 
they  are  polygonal,  bounded  by  straight  lines,  and  have  sharp  edges.  Lam- 
ination evident,  blue  or  yellow  cell-cavity,  yellow  dot.  Longitudinal  dis- 
tortions of  the  stripe  are  indicated  by  darker  lines,  which  usually  cross. 
b.  Chinese  Grass  and  Ramie. — Transverse  sections  isolated  or  a  small 
number  in  a  group ;  their  connection  very  loose ;  they  are  polygonal  or 
irregular,  and  very  large.  Lamination  very  evident ;  cell-cavity  large  and 
irregular,  often  rilled  with  dark  yellow  masses ;  sometimes  striated  radi- 
ally. The  breadth  of  the  fibres  is  very  variable,  in  the  longitudinal  aspect 
some  appear  very  broad  ;  distortions  evident;  the  ends  thickly  rounded. 
c.  Boa-fibre. — Transverse  sections  not  many  in  a  group,  polyhedral,  usu- 
ally with  straight  or  slightly  curved  sides  and  rounded  edge ;  cell-cavity 
narrowly  oblong,  regular;  contents  sometimes  yellow.  Some  transverse 
sections  are  surrounded  by  a  thin  greenish  lamella,  and  show  well-marked 
radial  striae  or  fissures,  and  concentric  lamination ;  the  separate  lamellae 
vary  in  depth  of  color. 
d.  Cotton. — Transverse  sections  always  isolated,  rounded,  of  various 
forms,  usually  kidney-shaped  ;  cell-cavity  narrow,  linear];  contents  usually 
yellow.    No  lamination. 
II.  Transverse  sections  blue  or  violet,  polyhedral,  rounded  or  irregular, 
always  surrounded  by  a  yellow  middle  lamella. 
a.  Hemp. — Transverse  sections  always  in  groups,  contiguous,  with 
rounded  edge,  surrounded  by  a  thin  yellow  middle  lamella,  beautifully 
laminated  concentrically  ;  cell-cavity  linear,  simple  or  branched,  irregular, 
sometimes  broad,  without  contents. 
b.  Sunn-hemp. — Transverse  sections  numerous  in  a  group,  closely  contig- 
uous resembling  those  of  hemp,  often  sickle-shaped,  either  polyhedral  or 
oval,  with  a  small  round  cell-cavity ;  often  with  yellow  contents.  Sur- 
round, d  by  a  broad  yellow  middle  lamella,  from  which  the  inner  laminae 
are  often  detached. 
B.  Colored  yellow  by  iodine  and  sulphuric  acid. 
I.  Dicotyledons.  No  vessels  besides  the  bast  fibres;  cell-cavity  with  con- 
strictions. 
1.  Transverse  sections  in  groups,  polygonal,  bounded*  by  straight  lines, 
with  sharp  edges ;  cell-cavity  round  or  oval,  smooth,  empty ;  surrounded  by 
a  narrow  middle  lamella  of  the  same  color. 
