ON  THE  CONSTITUTION  OF  QUININE. 
243 
The  analyses  of  the  double-salt  with  chloride  of  platinum  are 
in  favor  of  the  formula  with  40C.  Liebig  found  26*5,  26*6  and 
26*6  p.  c.  platinum.  Laurent  and  Gerhardt  26*3  to  26*6  p.  c. 
The  formula  C40  H24  N2  04+2H  Cl+2Pt  Cl2  wants  26-9  p.  c,  but 
the  formula  C38  H22  N2  04+2H  CI  +  2Pt  Cl2  27*4  p.  c.  platinum. 
The  addition  of  water  to  the  formula,  as  Laurent  did,  reduces  the 
amount  of  platinum,  but  there  is  no  evidence  at  all  of  its  contain- 
ing such. 
As  further  proof  of  the  selected  formula,  I  may  mention  the  fol- 
lowing analyses  : 
Nitrate  of  Quinine.  If  the  officinal  sulphate  of  quinine  is  mixed 
with  nitrate  of  baryta^  and  the  resulting  solution  evaporated  spon- 
taneously, large  transparent  prismatic  crystals  are  formed,  which 
were  recrystallized  from  boiling  water.  0*5865  grm.  air-dry  crys- 
tals lost,  at  100c  Cent.  0.0245  grm.  water.  0*2726  grm.  dried  at 
100°  C.  gave  0*6205  grm.  carbonic  acid  and  0*1615  grm.  water 
which  leads  to  the  following  formula  :  C40  H24  N2  04,  HO,  N05-f 
2HO. 
Calculated.  Found. 
40  equiv.  C  -  -  -  240  62-0  -    -    -  62.1 
25    «     H  -  -  -  25  6*5  -    -    -  6-6 
3    "     N  -  -  -  42  —  ...  — 
10    "     O  -  -  -  80  —  ...  — 
387 
2    "    HO  -   -   -     18     4-4    -    -    -  4-2 
I  could  not  obtain  another  nitrate  in  crystals  with  more  nitric 
acid. 
Sulphate  of  Quinine.  The  officinal  sulphate  contains  7  equiv. 
(Regnault)  of  water  of  crystallization  ;  according  to  Robiquet 
8  equiv.  Owing  to  its  efflorescence  on  exposure  to  the  air,  it  is 
difficult  to  obtain  it  at  all  times  with  the  same  amount  of  water. 
After  exposure  to  dry  air  it  retains,  according  to  Robiquet,  still 
2  equiv.  of  water,  which  statement  I  can  confirm  as  results  of  my 
experiments.  For  this  reason  it  seems  to  me  proper  to  consider 
the  effloresced  salt  as  the  officinal,  as  this  only  might  in  the-shops 
be  found  of  the  same  composition. 
I.  1*9285  grm.  air-dry  salt  lost,  at  120°  C,  0*0895  grm.  water. 
