FORMULA  FOR  THE  FLUID  EXTRACTS. 
541 
thereby.  In  the  case  of*  myrrh,  the  tears  alone  should  be  used, 
reduced  to  powder  simply,  by  trituration  without  sifting. 
EXTRACTUM  RHEI  FLUIDUM. 
Take  of  Rhubarb  in  powder,  (No.  40, )  sixteen  ounces,  Troy. 
Sugar,  eight  ounces. 
Alcohol,  a  pint. 
Diluted  Alcohol,  a  sufficient  quantity. 
Moisten  the  Rhubarb  with  four  fluid  ounces  of  the  alcohol, 
pack  it  moderately  in  a  conical  percolator,  cover  it  with  a  disc 
of  cloth  and  pour  on  the  remainder  of  the  alcohol ;  when  it  has 
disappeared  from  the  surface,  continue  the  percolation  with  di- 
luted alcohol  until  three  pints  have  passed,  observing  to  sepa- 
rate the  first  pint  and  set  it  aside  in  a  warm  place  till  reduced  to 
six  fluid  ounces.  Add  the  sugar  to  the  other  two  pints,  evapo- 
rate it  to  ten  fluid  ounces,  and  whilst  hot  mix  it  with  the  con- 
centrated reserved  tincture  and  strain  if  necessary. 
Remarks.— This  formula  differs  but  little  from  the  officinal. 
The  use  of  strong  alcohol  at  first  enables  the  operator  to  ex- 
tract the  more  valuable  ingredients  and  get  them  in  a  concen- 
trated form  without  injury  from  heat.  The  6  fluid  ounces  of 
result  from  the  evaporation  of  the  first  tincture  is  a  thick  mo- 
lasses-like liquid  containing  nearly  all  the  resinous  and  odorous 
matter  of  the  root.  During  the  evaporation  of  the  last  tincture 
after  adding  the  sugar,  the  alcohol  is  more  rapidly  dissipated  if 
it  is  frequently  stirred  with  a  spatula.  It  is  important  to  free 
the  preparation  as  much  as  possible  from  alcohol,  in  evapor- 
ating the  saccharine  portion,  to  prevent  the  crystallization 
of  the  sugar,  as  enough  of  alcohol  is  retained  in  the  first 
liquid  to  supersede  the  necessity  of  adding  the  tincture  of  gin- 
ger. It  will  be  noted  that  the  aromatics  have  been  omitted 
from  this  formula.  This  has  been  done  for  the  following  rea- 
sons. 1st.  Fluid  Extract  of  Rhubarb  is  generally  prescribed 
with  other  medicines  in  which  case  it  is  easy  to  add  the  aromatica 
according  to  the  preference  of  the  prescriber.  2d.  Their  pre- 
sence covers  up  to  a  considerable  extent  the  peculiar  distinctive 
odor  and  taste  of  the  drug,  and  thus  prevents  a  correct  judg- 
ment of  the  perfection  of  the  preparation.  3d.  When  free  from 
the  aromatics,  the  fluid  extract  affords  a  means  of  making  the 
simple  syrup  of  Rhubarb  extemporaneously  that  is  very  con- 
venient in  warm  weather. 
