306 
Tincture  of  Rhubarb. 
\  An.  Jour.  Prakm. 
X     July  1,1873.. 
A  portion  of  the  leaves,  which  had  been  exhausted  with  alcohol, 
was  now  treated  with  ether.  The  ethereal  liquid  was  evaporated 
to  a  small  bulk  and  thrown  into  water,  when  a  small  amount  of  fatty 
matter  separated  and  floated  on  the  surface  of  the  water.  It  was 
absorbed  by  bibulous  paper,  to  which  it  communicated  a  greasy  stain, 
that  was  not  dissipated  by  the  application  of  heat.  During  the  evap- 
oration of  the  ethereal  liquid  a  small  quantity  of  green  waxy  matter 
was  deposited  on  the  sides  of  the  evaporating  dish. 
A  quantity  of  the  leaves  after  having  been  exhausted  respectively 
with  cold  and  boiling  water,  alcohol,  ether,  diluted  acids  and  alkaline 
solutious,  left  a  dark  brown  lignin,  which  was  converted  by  concen- 
trated sulphuric  acid  into  a  pasty  mass  soluble  in  water.  The  leaves, 
when  incinerated,  yield  about  five  per  cent,  of  ash,  in  which  potassa, 
lime,  oxide  of  iron,  silica,  sulphuric,  muriatic  and  carbonic  acids  were 
found. 
The  organic  constituents  are  albumen,  sugar,  tannin,  gallic  acid, 
gum,  extractive,  resin,  volatile  oil,  fatty  and  waxy  matter,  lignin  and 
a  substance  having  properties  analogous  to  saponin. 
ON  TINCTURE  OF  RHUBARB. 
By  J.  B.  Moore. 
This  tincture,  on  account  of  its  tendency  to  deposit  on  standing  an 
abundant  precipitate,  has  always  been  a  source  of  annoyance  to  phar- 
macists. This  instability  is  not  only  pharmaceutically  objectionable, 
but  is  especially  so  in  a  medicinal  point  of  view,  as  the  precipitated 
matter  has  been  ascertained  to  contain  a  portion  of  the  active  prin- 
ciples of  the  drug.  Chrysophanic  acid,  which  is  supposed  to  be  either 
one  of  the  elements  of  activity  of  rhubarb,  or  intimately  associated 
with  its  medicinal  virtues,  has  been  found  to  be  among  the  principles 
usually  contained  in  the  precipitated  matter.  Hence  it  is  important 
that  some  means  be  devised  to  render  the  tincture  more  permanent, 
and  to  prevent  this  deposit  from  occurring. 
•  To  myself  this  imperfection  in  the  officinal  tincture  of  rhubarb  has 
been  annoying,  not  only  on  account  of  my  consciousness  of  the  fact 
that  this  precipitation  depletes  the  preparation  of  a  portion  of  its 
medicinal  power,  and  thu<  detracts  from  its  reliability  and  efficiency 
as  a  medicinal  agent,  but  also  because  of  its  rendering  the  tincture, 
not  unfrequently,  unsightly  in  appearance,  and  causing  it  to  be  cloudy 
