ON  ASCLEPIAS  TUBEROSA  (PLEURISY  ROOT.) 
493 
A  decoction,  when  allowed  to  cool,  gave  evidence  of  being 
strongly  charged  with  starchy  when  tested  by  iodine  ;  and  the 
presence  of  gum  was  determined  by  appropriate  tests. 
The  ligneous  portion  of  the  root,  when  freed  from  other  matters 
by  solvents,  amounted  to  from  30  to  35  per  cent,  of  its  weight. 
The  ethereal  extract  is  a  brownish  yellow  mixture  of  resin, 
fixed  oil  and  coloring  matter.  The  root  after  exhaustion  by 
ether  affords  to  alcohol  a  resin  not  soluble  in  ether. 
When  the  syrupy  alcoholic  extract  of  the  root  is  thrown  into 
water  and  allowed  to  stand,  an  oleaginous  yellow  colored  matter 
rises  to  the  surface  ;  no  precipitate  of  consequence  occurs.  By 
evaporation  an  extract  is  obtained,  which  forms  a  cloudy  homo- 
geneous mixture  with  water  possessed  the  taste  of  the  root, 
and  appeared  to  retain  fixed  oil  and  resin  in  intimate  mixture 
in  suspension. 
Repeated  distillation  of  the  root  aiforded  no  volatile  oil,  but 
the  distilled  water  was  odorous  of  the  root,  and  the  receiver  was 
contaminated  with  a  solid  substance.  This,  when  removed  by 
ether,  and  the  latter  evaporated,  appeared  to  be  a  volatile,  fatty, 
odorous  substance. 
The  drug  appears  to  contain  a  peculiar  principle  precipitable  by 
tannic  acid.  The  concentrated  cold  infusion  was  treated  with 
tannic  acid  till  reaction  ceased,  and  the  precipitate  was  collected, 
washed,  pressed,  and  mixed  with  an  excess  of  litharge  and  dried. 
This,  when  exhausted  with  hot  alcohol,  decolorized  and  evapo- 
rated, yielded  a  small  quantity  of  a  yellowish  white  powder,  pos- 
sessing the  peculiar  taste  of  the  root,  soluble  in  ether,  much  less 
soluble  in  water,  and  precipitable  by  tannic  acid. 
The  root  also  contains  much  extractive  matter.  The  ashes  of 
the  root  afforded  potassa,  soda,  sulphuric  acid,  lime,  oxide  of  iron, 
magnesia  and  oxide  of  manganese. 
Medical  Properties. — The  pleurisy  root  is  stated  to  be  dia- 
phoretic and  expectorant,  without  being  stimulant.  It  has  been 
considerably  employed  in  medicine  as  a  remedy  in  pleurisy, 
pneumonia,  catarrh,  and  other  pectoral  affections,  and  its  popular 
name  has  arisen  from  this  use.  It  has  also  been  employed  in 
febrile  diseases,  acute  and  chronic  rheumatism,  diarrhoea  and 
dysentery.    It  appears  in  large  doses  to  be  mildly  cathartic. 
Being  desirous  of  having  its  merit  tested  therapeutically,  a 
