536 
ON  THE  ALKALOIDS  OF  THE  CINCHONAS. 
different  thing  from  that  which  is  now  called  by  that  name  in 
Germany  and  France,  and  the  German  product  is  very  often  mixed 
in  considerable  proportion  with  that  discovered  by  Henry  and 
Delondre.  All  the  details  of  the  properties  and  composition  of 
these  two  quinidines  will  be  found  in  my  memoir.  I  will  only  add, 
that  one  of  them,  for  which  I  retain  the  name  of  quinidines  is 
hydrated,  efflorescent,  isomeric  with  quinine,  deviates  the  plane  of 
polarization  to  the  right,  and  possesses,  like  quinine,  the  character 
of  acquiring  a  green  color  by  the  successive  addition  of  chlorine 
and  ammonia  ;  whilst  the  other,  to  which  I  give  the  name  of  cm- 
chonidine,  is  anhydrous,  isomeric  with  cinchonine,  exercises  a 
rotatory  power  to  the  left,  and  does  not  exhibit  the  green  colora- 
tion. This  is  now  the  most  abundant  of  the  two  in  commercial 
samples.  It  is  always  very  easy,  by  exposing  a  recent  crystalliza- 
tion of  cinchonidine  to  wrarm  air,  to  ascertain  whether  it  contains 
any  quinidine.  All  the  crystals  of  the  latter  base  effloresce  imme- 
diately, retaining  their  shape,  and  standing  out  of  a  dead  white 
amongst  the  clear  crystals  of  cinchonidine.  We  may  also  recur 
to  the  character  of  the  green  coloration  by  chlorine  and  ammonia. 
There  are  consequently  four  principal  alkalies  in  the  cinchona 
barks,  quinine,  quinidine,  cinchonine  and  cinchonidine. 
4.  Action  of  Heat  on  Cinchonine  and  Cinchonidine. — I  have 
submitted  the  two  new  bases  quinidine  and  cinchonidine  to  the 
moderate  action  of  heat,  as  I  had  done  with  quinine  and  cinchonine, 
and  with  exactly  the  same  results  ;  that  is  to  say,  the  two  new 
bases  are  converted  into  isomeric  bases,  weight  for  weight,  with 
the  same  facility  and  under  the  same  conditions  as  quinine  and 
cinchonine.  But,  moreover,  and  this  is  undoubtedly  one  of  the 
most  important  facts  in  this  investigation,  the  two  new  bases 
obtained  by  the  transformation  of  quinidine  and  cinchonidine  are 
identical,  the  first  with  quinicine  and  the  second  with  cinchonicine. 
In  this  manner  wTe  arrive  at  this  remarkable  result,  that  of  the  four 
principal  bases  contained  in  the  cinchona  barks,  namely,  quinine, 
quinidine,  cinchonine  and  cinchonidine,  the  first  two  can  be  con- 
verted, weight  for  weight,  into  a  new  base,  quinicine,  which  proves 
that  they  are  themselves  isomeric ;  whilst  the  two  others  are  con- 
verted under  the  same  conditions  into  a  second  base,  cinchonicine, 
which  proves  that  they  are  also  isomeric. 
The  molecular  relations,  to  which  these  results  call  the  attention 
