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TESTS  EOR  THE  CINCHONA  ALKALOIDS. 
in  a  remarkable  and  simple  relation  to  chinovic  acid.  It  thus 
became  necessary  to  examine  again  saponin  and  caincic  acid, 
which  has  the  same  percentage  composition  as  the  substance 
from  the  seeds  of  the  Horse-chestnut,  and  also  chinovic  acid. 
The  author  has  undertaken  the  investigation  of  saponin,  and 
has  obtained  from  it,  by  the  action  of  potash,  a  beautifully  crys- 
tallized acid,  together  with  an  amorphous  substance,  which 
latter  is  again  decomposed  by  muriatic  acid  into  two  products. 
The  experiments  of  Schnedermann  are  completely  confirmed, 
and  all  uncertainty  which  could  not  be  got  rid  of  either  by 
Rochleder  and  Schwarz,  or  by  the  persevering  researches  of 
Belley,  entirely  disappears.  —  Ghent.  0az.f  April,  1858,  from 
Sitzungsher.  der  Akad.  der  Wiss.  zu  Wien. 
TEST  FOR  CINCHONA  BARK  AND  ITS  ALKALOIDS. 
Owing  to  the  difficulty  of  distinguishing  between  cinchona 
bark  and  other  barks  substituted  for  it,  in  cases  where  it  is  not 
possible  to  extract  the  bases  and  examine  them,  Hr.  Grahe  has 
endeavored  to  obtain  some  means  of  determining  this  point 
readily.  He  finds  that  true  cinchona  bark,  when  submitted  to 
dry  distillation,  gives  a  product  of  a  bright  carmine  color.  This 
product  is  characteristic  of  these  barks,  and  is  not  furnished  by 
any  others  that  do  not  contain  the  cinchona  alkaloids.  The 
quantity  of  this  red  substance  depends  upon  the  amount  of  the 
alkaloids,  and  it  appears  to  afford  a  tolerable  indication  of  this 
amount.  The  test  is  applied  by  heating  a  fragment  of  the  bark 
weighing  about  five  or  ten  grains,  in  an  ordinary  test  tube,  and 
gradually  raising  the  heat  to  redness.  With  cinchona  bark  a 
whitish  smoke  is  given  off,  and  also  water  vapor,  which  condenses 
on  the  sides  of  the  tube.  Very  shortly  afterwards  the  red  color 
begins  to  appear,  communicating  to  the  vapor  a  reddish  tinge, 
and  at  about  one  inch  distant  from  the  heated  portion  of  the 
tube  there  is  deposited  a  red  pulverulent  film,  which  gradually 
passes  into  a  thick  oleaginous  liquid,  running  down  the  glass  in 
drops  or  streaks  of  a  fine  carmine  color  in  the  water  condensed 
with  it.  Close  to  this  point  are  deposited  the  tarry  products 
generally  resulting  from  the  destructive  distillation  of  vegetable 
substances. 
