PHARMACY  OF  THE  CINCHONAS. 
297 
lime,  previously  rubbed  together  in  a  mortar ;  fit  the  cork  into 
its  place,  and  shake  the  mixture  well.  If  it  be  Yellow  Cin- 
chona, somewhat  less  of  this  mixture  will  be  required,  but  as  a 
surplus  is  not  hurtful  the  quantity  may  be  the  same  for  either. 
Common  sugar-refiners'  bone  black  in  powder  answers  a  good 
purpose,  and  the  fresher  it  is  the  better.  The  lime  should  be 
recently  slaked  and  well  hydrated.  Eight  parts  clean  lump  lime 
and  five  parts  water  are  good  proportions  for  slaking,  and  give  a 
damp  powder.  This  mixture  of  bone  black  and  lime  may  be  in- 
troduced into  the  flask  when  the  percolation  is  about  half  accom- 
plished, if  it  can  be  done  with  such  dexterity  as  to  avoid  loss  or 
risk.  This  saves  some  time,  but  had  better  not  be  undertaken 
by  the  inexpert.  If  so  introduced,  it  should  be  shaken  round 
with  the  percolate  so  as  not  to  fall  to  the  bottom  and  lie  there  in 
a  mass  to.  become  hard  and  unmanageable.  The  mixture  in  the 
flask  is  to  be  well  and  frequently  shaken  during  one  or  two 
days,  and  the  oftener  the  better  until  on  settling  the  clear  liquid 
above  appears  to  be  of  a  sherry  wine  color.  For  the  first  12  or 
24  hours  the  mixture  remains  thick  and  muddy  looking ;  after 
that  the  sediment  settles  out  between  the  shakings  and  the  upper 
stratum  is  seen  to  become  less  colored  the  longer  it  is  shaken 
together,  but  the  writer  has  never  seen  it  become  perfectly  deco- 
lorized as  described  by  Winckler.  When  of  a  sherry  wine  color 
that  is  quite  sufficient  for  all  practical  purposes.  A  five-inch 
filter  is  then  folded,  wetted  with  alcohol  and  placed  in  the  funnel, 
and  the  funnel  placed  in  the  other  of  the  two  flasks.  The 
upper  clear  portion  of  the  mixture  is  then  first  passed  through 
this  filter,  and  then  the  sediment  is  poured  upon  it,  taking  care 
never  to  fill  the  filter  more  than  about  two-thirds  full  until  the 
last  portion  is  poured  in,  and  then  not  above  three-fourths. 
When  the  clear  liquid  shall  have  pretty  well  drained  off  from  the 
sediment,  pour  on  to  this  latter  about  1  fluidounce  of  alcohol,  to 
displace  the  liquid  still  held.  Then  with  the  point  of  a  small 
spatula  remove  as  much  of  the  sediment  from  the  filter  as  is 
easily  practicable  without  breaking  or  injuring  the  filter,  and 
return  it  to  the  flask  whence  it  came.  Then  add  to  it  2  fluid- 
ounces  of  alcohol,  shake  it  vigorously  for  some  minutes,  and 
return  it  to  the  filter  in  the  funnel  with  the  same  precautions  as 
