576 
Homoquinine  of  Cuprea  Bark. 
Am.  Jour.  Pharm. 
Nov.,  1884. 
expressed  and  that  lie  suggests,  as  it  were,  as  an  apology  for  having 
confirmed  the  existence  of  homoquinine,  the  possibility  of  quinine 
becoming  "modified"  under  certain  conditions  and  then  behaving  as 
a  distinct  alkaloid.1 
We  had  long  been  aware  that,  in  operating  upon  homoquinine  with 
a  view  to  its  purification  and  the  preparation  of  salts,  there  was  some- 
times an  apparent  disappearance  of  the  substance,  as  it  were,  under 
one's  hands,  in  a  way  that  was  unaccountable,  and  that  then  the 
presence  of  quinine,  or  of  an  alkaloid  resembling  it  in  solubility  in 
ether,  could  be  recognized  in  the  solutions;  but  we  had  always  ascribed 
this  latter  circumstance  to  the  admixture  of  quinine  with  our  material 
and  the  small  quantity  of  that  at  our  disposal  prevented  the  further 
settlement  of  this  point.    Another  circumstance,  which  at  first  seems 
slight,  seems  to  lend  considerable  probability  to  Dr.  Hesse's  statement 
as  to  the  convertibility  of  homoquinine  into  quinine,  was  the  failure  of 
all  attempts  to  detect  that  substance  in  commercial  quinine  sulphate 
manufactured  from  cuprea  bark.    With  a  view  to  obtain  a  workable 
quantity  of  homoquinine  we  have  repeatedly  examined  samples  of 
quinine  sulphate  which  we  had  every  reason  to  believe  had  been  derived 
from  cuprea  bark,  and  within  the  last  few  weeks  have  taken  advantage 
of  an  opportunity  to  repeat  the  attempt  with  material  of  this  descrip- 
tion ;  but  in  every  instance  we  have  failed  to  obtain  the  faintest  indi- 
cation of  the  presence  of  homoquinine.    But  with  every  respect  for  the 
trustworthy  nature  of  Dr.  Hesse's  observations,  so  far  as  they  go,  we 
must  confess  that  our  own  experience  in  dealing  with  this  remarkable 
substance  made  us  hesitate  before  accepting  unreservedly  the  statement 
that  it  is  a  modification  of  quinine  and  capable  of  being  converted  into 
quinine  by  the  action  of  caustic  soda.    Upon  receipt  of  Dr.  Hesse's 
paper,  therefore,  we  at  once  proceeded  to  follow  out  the  treatment  he 
describes  for  effecting  the  conversion  of  homoquinine  into  quinine.  A 
quantity  of  the  crystalline  substance,  obtained  by  treating  the  crude 
sulphate  from  cuprea  bark  with  ammonia  and  ether,  was  first  recrys- 
tallized  several  times  from  ether  in  order  to  separate  any  adherent 
quinine,  and  an  acid  solution  of  the  purified  substance  was  mixed  with 
a  10  per  cent,  solution  of  caustic  soda  in  excess  and  some  ether.  The 
alkaloid  at  first  precipitated  was  completely  dissolved  on  agitation,  the 
ether  solution,  as  well  as  the  alkaline  liquor  becoming  perfectly  clear. 
After  the  lapse  of  several  hours  there  was,  however,  no  separation  of 
1  See  October  No.,  p.  524. 
