434     Grindelia  Rohusta  aud  Grindelia  Squarrosa.  {'^^'sl^l'Sm:^^' 
brown ;  that  of  *G.  squarrosa  is  much  lighter,  the  involucre  and  stems 
being  of  a  straw  color,  the  leaves  pea-green. 
3.  The  leaves  of  G.  robusta  are  ovate,  slightly  serrate,  sessile  or 
clasping;  those  of  G.  squarrosa  are  lanceolate  or  obspatulate,  more 
deeply  serrate,  and  while  the  upper  leaves  may  be  sessile  or  clasping, 
those  lower  down  are  narrowed  at  the  base  to  the  midrib,  which  often 
extends  half  an  inch  or  an  inch  from  the  stem  before  widening  into 
the  blade  of  the  leaf. 
4.  The  flower-heads  of  G.  robusta  are  depressed  globular,  with 
the  scales  of  the  involucre  closely  appressed ;  those  of  G.  squarrosa 
are  nearly  conical  in  shape,  with  the  scales  of  the  involucre  extended 
or  squarrose,  giving  the  head  somewhat  the  appearance  of  a  burr. 
PROPERTIES. 
G.  robusta  has  the  reputation  of  being  almost  a  specific  for  certain 
forms  of  asthma,  and  externally  in  rhus  poisoning.  G.  squarrosa  has 
similar  properties,  but  is  less  known  and  used. 
HISTORY  OF  PREVIOUS  INVESTIGATIONS . 
In  1876,  Dr.  C.  J.  Rademaker  made  a  chemical  analysis  of  Grindelia 
robusta  (New  Remedies,  July,  1876).  He  exhausted  the  drug  with 
a  hydro-alcoholic  menstruum,  obtaining  from  the  evaporated  residue, 
by  treatment  with  ether,  ^^an  eleo-resin  having  the  physical  appear- 
ance of  balsam  of  tolu  and  the  odor  of  resin  of  turpentine. The 
oleo-resin  was  treated  for  alkaloid  by  treating  with  acidulated  water- 
filtering,  rendering  alkaline,  and  agitating  wdth  ether.  An  aqueous 
solution  of  the  ethereal  residue  had  '^an  alkaline  reaction,  and 
under  the  microscope  showed  well-formed  prismatic  crystals.^^ 
On  treating  for  organic  acids  by  acidulating  the  alkaline  fluid  from 
which  the  base  and  oleo-resin  had  been  extracted,  agitating  with 
ether,  and  evaporating  the  ethereal  layer,  a  residue  was  obtained,  the 
aqueous  solution  of  which  had  an  '^acid  reaction,  completely  neutral- 
ized alkalies  and  formed  salts.  Under  the  microscope  the  acid  showed 
well-formed  acicular  crystals.'' 
Before  my  work  was  completed  an  analysis  of  G.  robusta  was  made 
by  G.  Linwood  Libby,  an  abstract  of  which  is  given  in  the  Pharm. 
Era,  January,  1888.  He  found  an  oleo-resin,  an  acid  resin  and  a 
resin.  He  states  that  although  he  twice  followed  Dr.  Rademaker's 
process  carefully,  he  was  unable  to  verify  his  results. 
