Am.  Jour.  Pharm.") 
Jau.,  1884.  J 
Notes,  on  the  Cinchona  Alkaloids. 
43 
NOTES  ON  CINCHONA  ALKALOIDS. 
By  C.  H.  Wood  and  E.  L.  Barret. 
In  an  abstract  published  in  "Amer.  Jour.  Phar.,"  1882,  p.  75,  the 
authors  state  that  the  crystals  obtained  from  an  ethereal  extract  of 
cuprea  bark  were  composed  of  equal  quantities  of  quinine  and  quini- 
dine.  They  have  since  then  investigated  this  subject  more  closely,  and 
publish  the  results,  etc.,  in  the  present  paper.  In  the  first  case  equal 
quantities  of  quinine  and  quinidine  sulphates  were  dissolved  separately 
in  acidulated  water,  the  solution  shaken  with  ether,  excess  of  soda 
added,  and  the  whole  agitated ;  as  soon  as  the  precipitates  had  dis- 
solved in  the  ether,  the  ethereal  solutions  were  decanted  off  and  mixed. 
The  crystals  deposited  from  this  mixed  solution  yielded,  on  analysis, 
numbers  approximating  to  the  composition  1  mol.  quinine  +  1  mol. 
quinidine  -J-  2JH20.  In  another  experiment  equal  weights  of  the 
alkaloids  were  dissolved  together  in  50  per  cent,  spirit.  The  crystals 
obtained  from  this  solution,  after  48  hours'  exposure  over  sulphuric 
acid,  were  similar  in  constitution  to  those  described  above.  Whilst  in 
a  third  experiment  equal  weights  of  the  two  sulphates  were  dissolved, 
etc.,  as  in  the  first  experiment,  but  the  alkaloids  were  taken  up  with 
warm  benzene.  This  time  the  crystals,  even  after  three  days'  expo- 
sure, were  found  to  contain  1  mol.  quinine  -|-  1  mol.  quinidine  -f 
2tT20  -f  C6H6.  From  these  facts  the  authors  infer  that  the  crystals 
always  contain  water,  and  therefore  this  compound  is  a  hydrate  of  the 
two  alkaloids. 
When  anhydrous,  a  mixture  of  quinine  and  quinidine  has  a  lower 
melting  point  than  either  of  the  constituent  alkaloids.  Some  of  the 
anhydrous  double  body  dissolved  in  dry  benzene  had  deposited  only  a 
very  few  crystals,  after  remaining  corked  up  ten  days,  but  on  removing 
the  cork  and  exposing  the  contents  of  the  flask  to  the  air  plenty  of 
crystals  soon  formed,  and  in  two  days  the  solution  was  half  filled  with 
them.  Quinine,  prepared  from  the  sulphate,  when  dissolved  in  warm 
benzene,  forms  rhomboidal  crystals  of  the  composition  2  mols.  quinine 
+  2H20  -f-  C6H6.  They  lose  the  benzene  slowly;  a  sample  after  being 
kept  for  some  time  had  lost  all  odor  of  benzene,  but  gave  evidence 
of  the  presence  of  the  hydrocarbon  when  treated  with  an  acid.  The 
authors  remark  on  the  analogy  these  crystals  bear  to  those  of  the 
quinine  and  quinidine  compound  when  crystallized  from  the  same 
