«\.m.  Jour.  Pharm.  ) 
July  1, 187:5.  j 
Tincture  of  Rhubarb. 
309 
not  usually  manifest  the  slightest  evidence  of  deposit  until  about  three 
weeks  after  it  is  prepared,  and  then  the  precipitation  proceeds  very 
^slowly  and  very  sparingly,  while  the  officinal  tincture  begins  to  throw 
down  a  copious  deposit  in  a  few  hours  after  it  is  made.  I  tried  in 
several  experiments  increasing  the  proportion  of  glycerin  to  six  fluid- 
onuces,  but  with  no  advantage  whatever — in  fact  with  less  satisfac- 
tory results. 
And,  furthermore,  the  menstruum  was  not  so  satisfactory  to  work 
with,  and  the  drug  was  not  so  easily  nor  so  thoroughly  exhausted  as 
when  the  proportions  in  the  formula  above  were  adhered  to.  It  has 
been  suggested  to  increase  the  alcoholic  strength  of  this  tincture,  in 
order  to  prevent  the  deposit,  but  this  I  deemed  objectionable,  as  the 
spirituous  strength  of  the  preparation  should  not  be  augmented,  if 
possible  to  avoid  it;  in  fact,  this  property  should  be  decreased  in  al- 
most all  tinctures  to  the  minimum  consistent  with  their  integrity  and 
permanence.  Glycerin  being  so  excellent  a  solvent  for  rhubarb,  and 
so  eligible  both  therapeutically  and  pharmaceutical^,  that  I  at  once 
summoned  it  to  my  aid  in  forming  a  menstruum  that  would  not  only 
exhaust  the  drug  thoroughly,  but  at  the  same  time  hold  the  extracted 
matter  in  permanent  solution,  and  find  it,  practically,  to  answer  the 
purpose  almost  fully. 
The  menstruum  I  have  employed  is  much  more  satisfactory  to  use 
than  the  diluted  alcohol  of  the  officinal  formula,  as  the  percolation  is 
more  easily  accomplished  with  it «  for,  being  less  aqueous  than  the 
tatter,  there  is  less  tendency  or  likelihood,  in  case  the  powder  is  ac- 
cidentally packed  too  tightly,  for  the  percolation  to  cease  or  to  pro" 
€eed  too  tardily. 
When  rhubarb  is  very  dry,  as  it  often  is,  it  powders  so  easily  that 
it  is  almost  impossible,  unless  the  greatest  care  be  exercised,  to  get 
it  in  anything  like  a  uniform  moderately  coarse  powder,  as  continued 
contusion  and  rubbing  in  the  mortar  very  quickly  reduces  the  greater 
portion  to  a  very  fine  powder  before  the  remaining  portion  is  suffi- 
-ciently  fine  to  pass  the  sieve,  and  as  a  consequence  the  powder  is 
likely  to  be  too  fine  and  irregular.  This  result  can,  in  a  measure, 
be  avoided  by  sieving  the  powder  very  frequently  during  the  process. 
€ontuse  and  rub  it  for  a  few  minutes  only  at  a  time,  and  then  throw 
it  on  the  sieve,  and  the  portion  which  refuses  to  pass  return  to  the 
mortar  to  be  again  treated  in  like  manner,  and  thus  repeating  the 
operation  until  the  whole  is  reduced  to  the  requisite  degree  of  fine- 
