ON  GELSEMINUM  SEMPERVIRENS. 
201 
experiments,  we  may  infer  that  dry  acrid  resin  is  one  of  its 
constituents. 
The  waters  into  which  the  evaporated  tinctures  were  thrown, 
in  the  above  experiment,  after  the  resin  had  subsided,  were 
evaporated  to  dryness.  The  resulting  extract  possessed  the  taste 
and  odor  of  the  drug.  This  was  dried  upon  glass,  and  a  small 
quantity  was  thus  obtained  in  the  form  of  scales  of  a  very  fine 
garnet  color,  very  soluble  in  water,  to  which  menstruum  it  imparted 
a  brilliant  yellow  color.  Yellow  coloring  matter  is  consequently, 
also,  one  of  its  constituents. 
Two  thousand  grains  of  the  bruised  root  were  distilled  with  a 
saturated  solution  of  chloride  of  sodium.  The  distillate  was 
quite  milky,  when  to  my  surprise,  the  oil,  instead  of  floating  upon 
the  surface,  quickly  sunk  to  the  bottom  of  the  receiver ;  thus 
evidently  showing  a  specific  gravity  unusual  for  volatile  oils.  I 
did  not  succeed  in  obtaining  the  exact  specific  gravity  of  this  oil, 
owing  to  the  difficulty  in  operating  upon  such  small  quantities  at  a 
time.  This  quantity  of  root  yielded  about  ten  minims  of  oil 
free  from  water,  the  water  of  course  holding  some  in  solution. 
The  oil  has  the  odor  of  the  plant  to  a  considerable  extent,  if  the 
distillation  is  conducted  at  a  low  heat ;  if  the  heat  is  raised, 
however,  the  oil  is  very  liable  to  become  empyreumatic.  A  heavy 
volatile  oil  is  clearly  shown  to  exist. 
Five  thousand  grains  of  the  bruised  root  were  macerated  for 
twenty-four  hours  in  sufficient  cold  water  to  cover  it.  After  the 
root  had  become  thoroughly  saturated  with  moisture,  it  was  trans- 
ferred to  a  displacement  apparatus,  and  cold  water  allowed  to 
percolate  slowly,  till  the  mass  was  exhausted.  This  liquid  was 
evaporated  upon  a  water  bath  to  one  pint,  and  filtered  to  separate 
the  coagulated  albumen,  and  oxygenated  matters  that  had  pre- 
cipitated. It  was  again  carefully  evaporated  to  dryness,  yield- 
ing a  deep  brown  extract,  weighing  nine  hundred  and  thirty 
grains.  Extractive  matter  soluble  in  water,  also  forms  a  part  of 
the  constituents. 
Investigation  of  the  Aqueous  Extract  The  aqueous  extract 
possessed  the  peculiar  bitter  taste  and  odor  of  the  plant.  It  was 
perfectly  soluble  in  cold  water,  sparingly  so  in  cold  alcohol,  but 
boiling  alcohol  dissolved  about  one  half.  The  solutions  all  showed 
the  presence  of  an  acid  by  litmus  paper,  an  1  were  more  or  less 
colored. 
