As^ptJembef,hiS'}    Elm  Bark,  Flaxseed  and  Mustard.  461 
employed,  and,  when  the  yellowish  shade  results,  additional  muci- 
lage must  be  added  to  counteract  the  excess. 
ASH. 
Incineration  of  seven  specimens  showed  the  presence  of  8-62, 
9-13,  9  22,  7-64,  8-io,  8-o8,  1010  per  cent,  of  ash  respectively, 
the  average  being  8-69  per  cent.;  observed  maximum,  io-io  per 
cent.;  observed  minimum,  7-64  per  cent.  Each  of  the  foregoing 
results  is  the  average  of  several  incinerations  of  the  same  specimens 
of  bark,  which  agreed  very  closely. 
SUMMARY. 
Elm  bark  contains  starch,  enough  to  respond  to  the  iodine  test, 
and  this  fact  should  be  stated  in  the  Pharmacopoeia.  It  should  also 
be  stated  that  when  powdered  elm  is  boiled  with  water  the  muci- 
lage, if  acidulated  with  sulphuric  acid,  on  the  addition  of  dilute 
iodine  solution,  should  turn  blue,  and  retain  its  color  for  some  time. 
Elm  bark  contains  so  little  starch  that,  in  my  opinion,  a  comparative 
test  can  be  easily  devised  that  will  determine  any  fraudulent  admix- 
ture of  starch,  and  in  justice  to  the  trade  a  method  to  detect  added 
starch  should  be  recorded  in  the  Pharmacopoeia.  The  Pharma- 
copoeia should  also  limit  the  amount  of  ash. 
Elm  bark  contains  a  natural  constituent,  capable  of  disturbing  the 
iodine  starch  test,  for  if  a  blue  solution,  made  by  adding  freshly  pre- 
pared iodide  of  starch  to  water  to  distinct  coloration,  be  mixed  with 
its  bulk  of  mucilage  of  elm,  the  mixture  will  be  immediately  decol- 
orized. The  blue  color  will  be  partly  restored  by  the  addition  of 
dilute  sulphuric  acid. 
According  to  preliminary  experiments  this  phenomenon  is  most 
probably  due  to  the  presence  of  both  tannin  and  an  organic  calcium 
compound,  which  may  be  isolated  from  the  bark.  Report  on  these 
constituents  is  reserved  for  the  future. 
FLAXSEED. 
The  seed  of  Linum  usitatissimum,  Linne.  (nat.  ord.  Lineae). 
About  4  or  5  mm.  long,  oblong-ovate,  flattened,  obliquely  pointed  at  one 
end,  brown,  glossy,  covered  with  a  transparent,  mucilaginous  epithelium,  which 
swells  considerably  in  water;  the  embryo  whitish,  or  pale  greenish,  with  two 
large,  oily,  plano-convex  cotyledons,  and  a  thin  perisperm;  inodorous;  taste, 
mucilaginous,  oily  and  bitter. 
Ground  linseed  (linseed  meal  or  flaxseed  meal)  for  medicinal  purposes  should 
