300  The  Cinchona  Alkaloids.  { *m)lT; ilX™' 
in  hot  water  without  fusing,  and  on  cooling  separates  in  needles  ;  the 
latter  fuses  in  boiling  water,  and  on  cooling  does  not  crystallize.  A 
solution  of  quinia  in  an  excess  of  diluted  H2S04  has  a  blue  fluores- 
cence, while  with  a  solution  in  diluted  HC1  this  is  not  the  case.  The 
fluorescence  disappears  also  upon  the  addition  of  other  substances,  nota- 
bly of  chlorides.  Quinia  solution  turns  polarized  light  to  the  left.  Chlo- 
rine and  ammonia  in  excess  cause  a  green  coloration  (thalleiochin). 
The  neutral  sulphate  2C20H24N2O2.SO4H2-|-8H2O  is  very  efflorescent ; 
the  medicinal  salt  should  contain  15*3  per  cent,  water  of  crystalliza- 
tion =  7!  H20. 
Quinidia  (conchinin),  isomeric  with  quinia,  but  rotating  to  the  right, 
was  discovered  by  van  Heijningen  ;  it  crystallizes  from  alcohol  with 
l\  H20  in  efflorescing  prisms  ;  from  ether  in  rhombohedrons  with 
2H20  ;  from  boiling  water  in  delicate  plates  with  \\  H20  ;  in  the  two 
latter  forms  it  does  not  effloresce  at  the  ordinary  temperature.  The 
salt  mostly  met  with  in  commerce  has  the  formula  2C20H24N2O2.SO4H2 
+  2H20. 
^uinicia^  C20H24N2O2.  By  heating  the  sulphate  or  other  salt  of 
quinia  or  conchinia  until  melted  it  is  transformed  into  sulphate  of  quin- 
icia  without  losing  in  weight.  Quinicia  is  amorphous,  rotates  the  plane 
of  polarization  to  the  right,  and  is  never  present  in  cinchona  bark. 
Diconchinia,  C40H46N4O3,  the  principal  constituent  of  chinoidin,  is 
amorphous,  fluoresces  in  a  sulphuric  acid  solution,  like  quinia  and  quin- 
idia  ;  gives  a  green  coloration  with  chlorine  and  ammonia  in  excess, 
and  rotates  the  plane  of  polarization  to  the  right.  It  does  not  yield 
quinicia,  and  has  not  yet  been  converted  into  quinidia. 
Cinchonidia^-  C20H24N2O,  first  observed  by  Henry  and  Delondre 
(1833),  again  discovered  by  Winckler  (1844)  as  quinidia,  and  subse- 
quently called  x  quinidia  by  Kerner,  crystallizes  from  alcohol  in  shin- 
ing prisms,  rarely  in  delicate  white  needles  or  plates,  the  crystals  being 
anhydrous.  Its  solutions  rotate  the  plane  of  polarization  to  the  left, 
are  not  fluorescent  and  not  colored  green  by  chlorine  and  ammonia. 
The  sulphate  has  the  formula  2C20H24N2O.SO4H2+6H2O,  and  is  nearly 
insoluble  in  chloroform,  but  swells  with  it  to  a  jelly-like  mass. 
Cinchonia,  C20H24N2O  (isomeric  with  cinchonidia),  crystallizes  from 
hot  stronger  alcohol  in  shining  anhydrous  prisms.    Its  solutions  are 
1  The  author  states  that  Pasteur's  quinidia  consisted  of  nearly  2  parts  of  Wack- 
ier's  quinidia  and  1  part  of  Koch's  cinchonidia. 
