08 
SULPHATE  OE  QUINIA  AND  THE  ACETATES, 
of  that  salt,  making  about  14  grs.  in  |  oz.  of  the  solution.  The 
equivalent  weight  of  acetate  of  potassa  is  nearly  one  half  as 
large  again  as  that  of  the  ammoniacal  salt;  14  grs.  of  the  latter 
would  suffice  to  convert  about  37  grs.  of  disulphate  of  quinine 
into  the  acetate,  whilst  10  grs.  of  the  former  could  not  decompose 
over  19  grs.  of  the  quinine  salt.  Still  \  oz  of  spir.  Mind,  de- 
composes 6  grs.  of  sulphate  of  quinine  into  a  deposit  of  rapidlj 
forming  prismatic  crystals,  which  are  not  near  so  voluminous  as 
those  formed  by  the  potassa  salt. 
Again,  if  dilute  acetic  acid  be  neutralized  by  magnesia,  |  oz, 
of  that  solution  precipitates  the  above  solution  of  quinine  partly 
in  needles,  combined  to  stars  of  a  silky  appearance,  which  also 
appear  on  the  mixture  of  a  solution  of  acetate  of  zinc. 
The  crystals  of  acetate  of  quinine  form  more  beautifully,  though 
also  more  slowly,  in  the  solution  of  sulphate  of  quinine  in  diluted 
muriatic  acid.  I  have  obtained  them  in  beautiful  groups  of 
feathery,  tree,  or  fan-like  appearance.  I  have  satisfied  myself 
that  these  precipitates  consist  of  pure  acetate  of  quinine ;  those 
formed  by  the  potassa  and  zinc  salt  were  charred  in  a  porcelain 
vessel  over  the  spirit  lamp,  destroying  the  quinine  salt ;  the  resi- 
due  did  not  effervesce  with  acids,  neither  water  nor  acid  took  up 
anything  by  boiling  ;  therefore  nothing  inorganic  was  contained 
in  the  salt. 
Sometimes  the  crystals  are  at  first  transparent,  but  become 
opaque  after  being  left  under  the  liquid  for  a  while ;  they  do 
not  dissolve,  or  only  very  little  in  cold  water,  and  in  the  cold  solu- 
tions of  acetate  of  ammonia,  potassa  and  soda,  but  they  all  re- 
tain a  larger  portion  in  solution  after  they  have  been  boiled  with 
the  acetate  of  quinine.  Chloride  of  ammonium  seems  to  dissolve 
a  larger  portion  of  it,  for  when  a  solution  of  sulphate  of  quinine 
is  mixed  with  a  strong  solution  of  sal  ammoniac,  the  precipitate 
occasioned  by  acetate  of  potassa  is  less  in  quantity,  at  all  events 
it  does  not  stiffen  the  mixture,  as  is  the  case  if  that  addition  is 
not  made. 
To  repeat  these  experiments,  it  is  necessary  not  to  add  any 
more  of  the  acid  than  is  exactly  required  for  dissolving  the  sul- 
phate of  quinine  ;  an  excess  of  acid  decomposes  the  newly  formed 
acetate  of  quinine,  a  part  of  which,  or  all,  goes  in  solution  again 
%%  sulphate  or  muriate  of  quinine. 
