306 
Ethereal  Solutiooi  of  Quinia. 
{Am.  Jour.  Pharm, 
July  1, 1871. 
wards  again  by  10.  There  will  probably  be  found  more  than  1  grain 
of  quinia  contained  in  the  5  minims  ;  hence  it  is  now  only  necessary 
to  dilute  it  with  ether  to  the  required  strength.  Let  us  suppose  that 
the  residue  of  5  minims  weighed  IJ  grains,  and  that  our  remaining 
solution  measures  2J  fl.  oz.  ;  now  in  order  to  make  the  solution  con- 
tain 1  grain  in  every  5  minims,  we  have  the  proportion  : 
1  (grain  req.)  :  (grains  found)  2J-  (fl.  oz.)  :  x  (fl.  oz.  req.) 
whence  x  =  (fl.  oz.)  ;  hence  we  have  to  dilute  the  solution  with 
stronger  ether  so  as  to  measure  3J-  fl.  oz. 
The  original  amount  of  sulphate  of  quinia  (-364  grs.)  employed,  con- 
tains 40  grs.  of  sulphuric  acid,  and  324  grs.  of  quinia  ;*  now  if  all  the 
latter  were  to  remain  in  solution,  we  should  obtain  (at  the  rate  of 
1  grain  in  5  minims)  1620  minims  or  3  oz.  180  min. ;  but  during  the 
evaporation  a  portion  of  the  quinia  has  attached  itself  to  the  sides  of 
the  vessels  ;  and  this  should  not  be  scraped  into  the  solution,  since  it 
will  not  only  fail  to  redissolve,  but  will  generally  produce  a  further 
separation  of  quinia. 
It  will  sometimes  occur,  that  on  pouring  the  ether  upon  the  pre- 
cipitated quinia  in  the  bottle,  the  latter  absolutely  (or  nearly  so)  re- 
fuses to  dissolve;  this  is  owing  to  the  presence  of  undecomposed 
solution  of  bi-sulphate  of  quinia,  which  seems  to  prevent  the  solvent 
action  of  ether.  By  adding  a  little  more  ammonia  and  shaking,  the 
solution  will  at  once  take  place.  But  too  much  ammonia  must  be 
avoided,  since  this  gives  a  tendency  to  the  ethereal  solution  to  deposit 
the  quinia  in  a  short  time  ;  at  least  such  is  my  experience. 
The  quinia  adhering  to  the  sides  of  the  evaporating  vessel,  may  be 
dissolved  off  by  the  aid  of  a  little  dil.  sulphuric  acid,  and  kept  in  so" 
lution  for  future  use ;  its  amount  may  be  determined  by  drying  and 
weighing  the  graduate  together  with  the  crust  of  quinia,  and  re- 
weighing  it  after  its  removal.  Supposing  the  former  weight  is  1020 
grains,  the  latter  1000  grains,  the  difference  will  be  the  quinia,  20 
grs.    Now  as 
*The  author's  calculations  are  slightlv  incorrect ;  crystallized  sulphate  of 
quinia  must  be  heated  to  between  110  and  120°  C.  (230  and  2480F.)  to  lose  all 
its  water  of  crystallization,  when  it  still  retains  IHOof  constitution,  its  formula 
being  04oH2'iN2  O4, HO,  SO3  and  its  equivalent  weight  373,  containing  324  dry 
quinia  and  49HO,  SO3  See  Am.  Journ.  Ph.,  1855,  p.  243.  364  grains  sulphate 
of  quinia,  deprived  of  all  its  water  of  crystallization,  contain,  therefore,  316 
grains  dry  quinia. — Editor  Am.  Journ.  Ph. 
