406 
PHARMACY  OF  THE  CIHCHONAS. 
Alcohol  saved.  By  the  officinal  process  with  Diluted  Alcohol, 
when  either  evaporated  as  directed,  or  distilled  as  proposed, 
until  the  residue  measures  the  prescribed  two  pints,  all  the 
Alcohol,  practically  speaking,  will  have  passed  off,  leaving  a 
yellow  muddy  looking  liquid,  which,  with  the  sugar  added, 
measures  over  2J  pints,  and  requires  prolonged  heating  and 
stirring  to  get  it  down  to  the  prescribed  two  pints  of  finished 
product.  This  fluid  extract,  often  while  hot,  and  always  when 
cool,  is  a  muddy  looking  inelegant  preparation  too  thick  for  con- 
venient use,  and  yet  representing  the  Cinchona  in  double  its 
weight.  The  Alcohol,  however,  lost  by  the  officinal  evaporation, 
is  almost  entirely  saved  if  distilled  in  a  water  bath,  and  when 
diluted  to  the  prescribed  strength,  is  ready  for  use  again,  whilst 
the  additional  heat  required  for  distillation  is  mo're  than  counter- 
balanced by  the  long  exposure  and  oxidation  incident  to  evapo- 
ration. 
On  the  other  hand,  if  Alcohol  be  used  as  the  menstruum,  and 
in  sufficient  quantity  for  a  thorough  practical  exhaustion  of  the 
Cinchona,  the  percolate,  no  matter  how  large  in  quantity,  may 
be  distilled  in  a  water  bath  with  ease,  with  much  less  heating, 
in  a  much  shorter  time,  and  the  Alcohol  may  be  saved  with  the 
exception  of  12  to  20  per  cent,  loss,  incident  to  percolation  and 
distillation.    This  loss  is  about  the  same  upon  four  pints  as 
upon  six,  and  varies  with  the  amount  of  knowledge  and  skill 
applied  to  the  process.    The  residue  in  the  still  after  distillation 
consists  of  5  or  6  f^  of  dense  liquid  extract,  transparent,  of  a 
fine  rich  red  color,  nearly  free  from  Alcohol,  and  containing,  the 
whole  of  the  medicinal  properties  of  the  percolate,  unimpaired 
by  prolonged  heating  or  oxidation.    This,  by  ten  minutes  active 
stirring  on  the  water  bath,  may  be  reduced  without  change,  ex- 
cept in  consistence,  to  a  tenacious  extract,  weighing  less  than 
4a,  which  becomes  brittle  when  cold,  and  is  almost  entirely 
soluble  in  Alcohol.    This  extract  is  entirely  soluble  in  Glycerin 
in  all  possible  proportions,  and  the  solutions  appear  to  be  perma- 
nent.   It  is  also  soluble  in  all  mixtures  of  Glycerin  and  Alcohol ; 
and  in  all  mixtures  of  Glycerin  and  water  which  do  not  contain 
more  than  one-fourth  of  their  volume  of  water.    It  is  soluble  in 
a  mixture  of  equal  measures  of  Glycerin  and  water  while  hot, 
