106 
Researches  on  the  Cinchona  Alkaloids. 
j  Am.  Jour.  Pharm. 
(      Mar.,  1881. 
alkaloids  tlie  salts  of  the  same,  as  the  neutral  hydrochlorate  and  sul- 
phate, may  be  employed.  After  a  few  hours  the  formation  of  the  com- 
pound ether  is  completed,  and  the  solution,  after  the  addition  of  a  little 
water,  may  be  evaporated  in  a  capsule  at  a  moderate  heat.  The  amor- 
phous residue  is  then  dissolved  in  water,  a  slight  excess  of  ammonia 
water  added,  and  the  compound  ether  extracted  by  shaking  with  ether. 
The  ethereal  solution,  after  being  washed  with  cold  water,  is  allowed 
to  evaporate  slowly,  when  the  acetyl  compound  remains  behind.  With 
the  exception  of  the  acetyl-quinia,  all  these  compounds  are  amorphous; 
they  may  be  dried  at  100°C.  without  decomposition,  and  are  resolved 
when  boiled  with  an  alcoholic  solution  of  potassa,  with  absorption  of  a 
molecule  of  water,  into  acetic  acid  and  the  original  alkaloid.  It  may 
thus  be  easily  proved  that  the  product  obtained  from  quinia  and  quin- 
idia  is  free  from  quinicia,  and  that  that  from  cinchonidia,  etc.,  is  free 
from  cinchonicia.  The  saponification  even  takes  place  when  the  com- 
pound ethers  are  allowed  to  remain  in  contact  with  a  solution  of  caustic 
potassa  or  soda  for  a  long  time  at  ordinary  temperatures.  The  com- 
pound ethers  dissolve  readily  in  dilute  acids,  and  are  precipitated  from 
these  solutions  by  ammonia,  potassa  or  soda  in  a  resinous  form.  While 
the  solutions  of  acetyl-quinia  and  acetyl-quinidia  in  an  excess  of  diluted 
sulphuric  or  acetic  acid  show  a  blue  fluorescence,  this  property  is  not 
displayed  by  the  respective  solutions  of  the  other  compound  ethers. 
With  alcohol  all  these  compound  ethers  form  solutions  possessing  an 
alkaline  reaction  and  strongly  bitter  taste,  and  of  these  again  the 
acetyl-quinia  and  acetyl-quinidia  solutions  assume,  with  chlorine  and 
an  excess  of  ammonia  water,  a  deep  green  color,  while  the  solutions 
of  the  other  compound  ethers  do  not  show  this  reaction. 
Acetyl-quinia,  C2oH23(C2H30)N2^2)  obtained  by  the  evaporation  of 
the  ethereal  solution  in  colorless,  shining  prisms,  which  after  the  removal 
of  the  mother-liquid  and  washing  with  a  little  ether,  are  perfectly  pure.. 
It  melts  at  108°C.  (uncorr.),  and  solidifies  on  cooling  in  radiating  crys- 
tals; it  is  easily  soluble  in  alcohol  and  chloroform,  but  more  difficultly 
in  ether.  Its  solution  in  97  volume  per  cent,  alcohol  gives  at  ^=15°C.^ 
and  for  p=2  a  rotation  of  [a]<i=  — 54*3°,  and  for  the  same  amount 
in  water  with  3  molecules  HCl,  [a]^i=  — 114-8°.  The  platinum  salt 
forms  a  dark  yellow  amorphous  flocculent  precipitate,  sparingly  soluble 
in  cold  water  and  in  dilute  acids.  The  gold  salt  forms  a  bright  yellow 
flocculent  precipitate,  which  gradually  becomes  crystalline. 
Acetyl-quinidia  {conquinia),  C20^^23(C'2H3O)N2O2,  has  the  same  pro-  . 
