QUANTITATIVE  ESTIMATION  OF  ALKALOIDS,  ETC.  525 
NEW  PROCESS  FOR  THE  QUANTITATIYE  ESTIMATION  OF 
THE  ALKALOIDS  OF  THE  CINCHONA  AND  CALISAYA 
BARK. 
By  p.  Carles. 
The  author  begins  with  giving  a  review  of  the  different 
methods  hitherto  in  use  for  the  quantitative  estimation  of  the 
alkaloids  alluded  to,  which  methods  may  be  divided  into  two 
main  classes — viz.,  those  by  which  the  whole  of  the  alkaloids  arc 
estimated  together,  and  those  by  which  only  the  quinine  is  esti- 
mated.   The  author's  new  method  is  the  following :    A  fair 
average  sample  of  the  bark  to  be  tested  is  ground  up  to  a  fine 
powder,  and  sifted,  but  any  residue  left  on  the  sieve  is  to  be 
pulverized  again.    20  grms.  of  this  powder  are  taken  and  inti- 
mately mixed,  in  a  mortar,  with  8  grms.  of  quick-lime,  slaked, 
just  previous  to  use,  with  35  grms,  of  water.    The  pasty  mass 
thus  obtained  is  dried  on  a  water-bath.    As  soon  as  the  mixture 
has  become  dry  enough  to  be  broken  up  into  small  lumps,  this 
is  done,  and  the  lumps  placed  in  a  funnel-shaped  tube,  the  lower 
and  narrower  opening  of  which  is  closed  by  a  plug  of  cotton  wool. 
Chloroform  is  poured  over  the  mass,  a  quantity  of  150  grms. 
being  sufficient,  and  the  last  traces  of  that  fluid  are  washed  off 
with  some  distilled  water ;  the  larger  portion  of  the  chloroform 
is  eith'er  evaporated  or  (as  may  suit  the  operator)  distilled  off  on 
a  water-bath,  and  the  residue  taken  up  with  from  10  to  12  c.c. 
of  dilute  sulphuric  acid  (1  of  acid  to  10  of  water).    This  solution 
is  poured  on  to  a  previously  well-moistened  filter,  which  retains 
the  resinous  matters,  while  a  clear  liquid  runs  off.    The  filtrate 
is  boiled,  and  when  in  full  ebullition,  ammonia  is  added  to  it,  so 
as  to  leave  only  a  slightly  acid  reaction ;  all  the  sulphate  of 
quinine  crystallises  out,  while  the  mother-liquor  retains  the  rest 
of  the  alkaloids,  which  may  be  separated  by  precipitation  and 
further  tested.    The  author  has  added  to  his  paper  some  tabu- 
lated results  of  experiments  made  by  him  with  the  same  quantity 
of  bark,  and  operating  with  various  methods  executed  carefully, 
as  described  by  the  original  authors  and  suggestors  of  these 
methods,  in  order  thus  to  prove  the  superiority  of  his  method. — 
Lond.  Chem.  News,  Sept.  2,  1870. 
