AmMa°y,ri8P79arm'}       Accurate  Estimation  of  Quinia.  253 
iron  is  to  be  removed,  a  loss  of  the  alkaloid  must  occur  to  some  extent^ 
owing  to  its  slight  solubility  in  water.  The  following  modification  has 
been  found  to  give  more~accurate  results : 
Five  grams  of  the  citrate  to  be  taken.  Dissolve  in  50  cc.  of  water, 
add  a  slight  excess  of  dilute  ammonia  '960,  stir  well,  and  after  standing 
five  minutes  pour  on  to  a  double  filter,  made  of  two  filter  papers  of 
open  texture,  tared  on  a  balance,  one  against  the  other,  by  cutting  down 
the  heavier  ;  the  smaller  one  to  be  placed  outside  to  prevent  the  pre- 
cipitate getting  between  the  two.  This  dispenses  with  weighing  and 
drying  a  filter,  as  both  have  the  same  solutions  passing  through  them 
and  remain  equal  in  weight. 
Instead  of  distilled  water,  the  following  solution  is  to  be  used  for 
washing  :  r  oz.  of  ammonia  *88o  is  added  to  80  ozs.  distilled  water. 
The  precipitated  and  washed  quinia  from  one  drachm  of  the  sulphate 
is  added  to  the  dilute  ammoniacal  solution  and  well  shaken  during 
twenty-four  hours.  As  much  as  may  be  required  is  then  filtered  and 
used  in  an  ordinary  wash  bottle. 
The  precipitated  quinia  may  now  be  freely  washed  with  this  solu- 
tion ;  no  quinia  will  be  lost,  and  if  the  precipitation  has  been  properly 
performed  every  trace  of  iron  may  be  removed  in  from  five  to  ten 
minutes,  leaving  the  alkaloid  white  and  granular.  In  this  short  time 
any  quinia  deposited  by  evaporation  of  the  washing  solution  would  be 
so  small  that  it  may  be  neglected.  Remove  the  filter  from  the  funnel 
and  thoroughly  drain  on  bibulous  paper  for  two  or  three  hours.  If  the 
drying  be  commenced  without  this  precaution,  the  water  held  by  the 
precipitate  will,  on  becoming  hot,  dissolve  a  portion  of  it.  Dry  at  a 
temperature  not  exceeding  ioo°F.  until  constant  in  weight,  the  outside 
filter  acting  as  a  counterpoise. 
Very  accurate  results  have  been  obtained  as  above,  known  weights 
of  quinia  having  been  added  to  ferri  citras,  ferri  et  ammoniae  citras,  etc. , 
and,  though  it  may  appear  an  unnecessary  complication  of  the  B,  P. 
process,  it  really  requires  less  time  when  the  solution  is  kept  ready  made 
up.  The  suggestion  is  simply  an  adaptation  of  Teschemacher's  excel- 
lent method  of  estimating  morphia  in  opium. — Phar.  four,  and  Trans, 7 
Feb.  15,  1879,  p.  673. 
