^"ju°ri88r'°"}         ^^^^  0^       Cinchona  Alkaloids.  36S 
base  in  dilute  sulphuric  acid  shows  a  blue  fluorescence,  whilst  in  a 
solution  in  hydrochloric  acid  this  property  could  not  be  observed.  These 
solutions,  upon  the  addition  of  chlorine  and  an  excess  of  ammonia,, 
gave  a  dark  green  color. 
The  neutral  sulphate  crystallizes  in  delicate  colorless  crystals,  ^ 
which  have  a  great  resemblance  to  the  crystals  of  conchinine  sulphate. 
When  tested  in  the  same  way  as  conchinine  with  potassium  iodide  the 
same  result  is  obtained.  On  the  other  hand  its  solution  in  dilute 
sulphuric  acid  differs  from  that  of  conchinine  sulphate  in  its  resistance 
to  potassium  permanganate. 
With  respect  to  hydroquinine  the  composition  of  the  substance  dried 
at  120°  C.  corresponds  to  the  formula  C20H25N2O2. 
Found.  Calculated. 
C,     .  .  .  .       73-93  73-63 
H,         .  .  .  .    7-96  7-97 
Hydroquinine  is  precipitated  by  ammonia  from  the  blue  fluorescent 
solution  in  dilute  sulphuric  acid  in  white  amorphous  flocks,  which 
immediately  become  crystalline.  The  water  of  crystallization  in  the  air- 
dried  base  amounts  to  7*75  per  cent.,  though  in  well-formed  crystals  a 
higher  amount  might  be  found.  The  alkaloid  melts  at  168°C- 
(uncorr.),  dissolves  freely  in  alcohol  and  ether,  and  upon  the  evaporation 
of  the  solutions  is  left  behind  in  an  amorphous  form.  It  exhibits  with 
chlorine  and  excess  of  ammonia  the  same  reaction  as  quinine,  but 
resists  the  action  of  potassium  permanganate  for  a  longer  time. 
The  acid  platinum  salt,  C2oH26N202,PtCl6H2  +  2H20,  is  thrown  down 
as  an  amorphous  yellow  precipitate,  afterwards  becoming  crystalline. 
The  neutral  tartrate,  (C2oH26N202)2,C4HgOg-|-H20,  forms  colorless- 
prisms,  which  dissolve  very  sparingly  in  cold  water,  but  to  a  greater 
extent  than  crystals  of  neutral  tartrate  of  quinine. 
The  neutral  sulphate,  (C2oH2gN202)2,S04H2  +  H20,  crystallizes  in 
colorless  needles,  sparingly  soluble  in  cold  water.  In  acid  solution,, 
under  otherwise  similar  relations,  it  rotates  the  beam  of  polarized  light 
less  strongly  than  quinine  sulphate.  At  t=15°  and  p=4°  (anhydrous 
sulphate)  it  gave,  in  aqueous  solution  containing  four  mols.  HCl,  {a)i,= 
— 222*5°,  which  would  give  for  hydroquinine  under  these  conditions^ 
(rt)D=255-9. 
*The  neutral  sulphate  of  Forst  and  Bohringer's  hydroquinidine  (hydro- 
conchinine)  forms  thick  crystals  with  numerous  planes,  and  is  conse 
quently  not  identical  with  my  sulphate. 
