^^se^l'mi^'''^'}     Grrindelia  Eobusta  and  Grindelia  Squarrosa.  439 
grindelin  is  suggested  for  it.  It  is  probable  that  the  medical  proper- 
ties of  the  plants  are  due  to  this  substance. 
To  a  portion  of  the  aqueous  solution,  sulphuric  acid  was  added,  and 
allowed  to  stand  in  a  cool  place  for  48  hours.  At  the  end  of  that 
time  the  liquid  was  observed  to  have  a  large  number  of  minute  acicu- 
lar  crystals  floating  in  it.  These  were  filtered  off  and  dried,  and  on 
opening  the  filter,  they  separated  in  a  thin,  papery  cone,  glistening 
like  benzoic  acid.  These  crystals  were  thought  to  be  the  decomposi- 
tion-product of  grindelin,  brought  about  by  the  action  of  the  dilute 
acid  in  the  cold,  glucose  being  liberated. 
To  determine  whether  or  not  such  was  the  case,  a  gravimetric  esti- 
mation of  the  glucose  in  the  liquid  producing  the  crystals,  and  in  the 
aqueous  solution  to  which  no  acid  had  been  added,  was  made.  The 
supposition  was  verified,  as  the  former  yielded  0*26  per  cent,  more 
glucose  than  the  latter.  On  boiling  a  solution  with  dilute  acids,  a 
white  insoluble  substance  separates  out,  which  on  standing  unites  into 
a  resin,  having  properties  identical  Avith  that  found  in  the  drug.  The 
theory  is  advanced  that  the  resin  found  in  the  drug  is  wholly  a  decom- 
position product  of  grindelin,  the  greater  part  of  the  glucose  set  free 
being  used  by  the  plant  as  a  necessary  constituent  to  its  growth  and 
development. 
(d)  Tannin.  A  quantitative  estimation  of  tannin  was  made  with 
gelatin,  in  the  presence  of  alum.  An  immediate  precipitation  took 
place  in  the  solution  of  G.  robusta.  After  12  hours  this  was  filtered 
off,  washed,  dried  and  weighed.  50  per  cent,  of  the  dried  residue  was 
calculated  as  tannin,  giving  a  yield  of  about  IJ  per  cent. 
No  tannin  was  found  in  G.  squarrosa,  no  precipitate  having  formed 
at  the  end  of  12  hours. 
y.  TREATMENT  WITH  DILUTE  CAUSTIC  SODA. 
The  drugs  were  exhausted  with  a  dilute  solution  of  caustic  soda,  and 
the  substances  soluble  therein  estimated  as  pectin,  albuminoids,  and  allied 
bodies.   G.  robusta  yielded  5*68  per  cent ;  G.  squarrosa  3*56  per  cent. 
yi.  TREATMENT  WITH  DILUTE  HYDROCHLORIC  ACID. 
No  starch  is  present  in  either  drug. 
Total  extracted  by  above  solvent:  G.  robusta  217  per  cent.,  of 
which  1*06  per  cent,  is  calcium  oxalate.  G.  squarrosa  4.94  per  cent., 
of  which  1*00  is  calcium  oxalate. 
