426 
Commercial  ^inia  Sulphate. 
{Am.  Jour.  Pharm. 
Aug.,  1880. 
passed  from  his  hands  into  commerce.  Dr.  Kerner  suggests  that  the 
best  remedy  for  this  state  of  things  would  be  to  substitute  the  hydro- 
chlorate  in  place  of  the  sulphate,  inasmuch  as  it  is  a  more  constant 
salt,  and  it  has  been  found  to  possess  advantages  from  a  therapeutical 
point  of  view. 
Still,  since  quinia  sulphate  is  the  official  preparation  and  the  one  in 
general  use,  the  question  as  to  the  amount  of  water  in  a  sample  is,  as 
Dr  Kerner  insists,  one  of  importance  as  regards  the  determination  of 
relative  value  of  that  sample  ;  but  at  the  same  time  he  points  out  that 
it  is  not  easy  to  decide  what  may  reasonably  be  required  in  this  respect^ 
and  that  it  is  still  less  easy  to  determine  quickly  the  amount  of  water 
in  a  sample  of  quinia  sulphate  than  it  is  to  detect  minute  traces  of 
cinchonidia  not  indicated  by  the  ammonia  test.  In  most  manuals  of 
chemistry  the  neutral  quinia  sulphate  is  represented  by  the  formula 
2(C2qH24N202)H2S04  +  yHgO,  according  to  which  the  percentage 
amount  of  water  would  be  14*45.  Dr.  Hesse  adopts  formulae  with  jj- 
and  even  8  molecules  of  water,  but  Dr.  Kenner  has  invariably  found 
the  loss  of  weight  by  drying  at  ii5°C.  to  vary  between  14*38  and 
14*80  per  cent,  when  the  fresh  salt  pressed  between  the  blotting  paper 
and  protected  from  efflorescence  was  operated  upon.  Consequently, 
he  adopts  the  corresponding  formula  as  correct,  and  as  he  considers  it 
is  impracticable  in  factory  operations  to  prevent  efflorescence  altogether, 
while  thoroughly  removing  all  mechanically  adherent  water,  he  con- 
cludes that  it  must  be  regarded  as  a  well  founded  requirement  that 
official  quinia  sulphate  should  not  at  the  utmost  lose  more  than  14*6 
per  cent,  of  its  weight  when  dried  at  ii5°C.  As  a  general  rule  he 
considers  the  loss  of  weight  in  good  samples  would  be  only  13-8  to 
14*4  per  cent. 
By  exposure  to  dry  air  at  a  moderate  temperature  the  crystallized 
quinia  sulphate  gradually  loses  five  molecules  of  water,  or  10*32  per 
cent.,  forming  the  compound  2(C2qH24N202)H2S04-|-2H20,  contain- 
ing 4*6  per  cent,  water  and  82*86  per  cent,  dry  alkaloid.  This  salt  is 
heavier  than  the  above  mentioned  salt  with  seven  molecules  of  water^ 
and  it  has  not  so  good  an  appearance,  but  it  is  constant,  and  though  it 
can  be  thoroughly  deprived  of  water  of  crystallization^  even  by  drying 
at  ioo°C.,  the  anhydrous  salt,  2(C2oH24N202)H2S04,  containing  86*86 
1  See  Cownley  On  the  Water  of  Crystallization  in  Quinia  Sulphate,  "  Phar.  Journ.'* 
[3],  vii,  p.  189. 
