V 
^^'jiTJ'issr^'}  Pyridine  and  Quinoline  Bases.  327 
Guadeloupe  Vanilla. — Seven  or  eight  years  ago  a  new  vanilla  planta- 
tion was  established  in  Guadeloupe,  and  for  several  years  the  vanilla 
has  been  met  with  in  French  commerce.  It  is  quite  distinct  from  the 
Mexican  and  Bourbon  vanilla,  and  is  thought  by  Professor  Charbon- 
nier  to  be  probably  derived  from  a  variety  of  vanilla  planifolia,  and, 
perhaps,  to  undergo  a  different  process  of  curing.  Instead  of  being 
irregularly  triangular,  it  is  always  flattened,  of  a  blackish  color,  rather 
less  dark  than  in  the  Bourbon  and  Java  vanilla,  is  less  frequently 
covered  with  crystals  of  vanillia,  has  a  distinctive  oclor,  is  little 
wrinkled,  and  is  marked  with  fine  stride  in  a  longitudinal  direction. 
While  it  is  of  good  appearance,  resembling  Bourbon  vanilla,  its  odor 
is  less  fine,  and  on  use  disappears  quite  rapidly.  It  is  sold  at  about 
one  half  the  price  of  Bourbon  vanilla. — Rep.  de  Phar.,  1883,  p.  18. 
RECENT  RESEARCHES  ON  THE  PYRIDINE  AND  QUINOLINE 
BASES. 
Ever  since  it  was  shown  that  a  close  connection  exists  between  some  of 
the  important  natural  alkaloids  and  the  derivatives  of  pyridine  and  quino- 
line, researches  intended  to  aid  in  determining  the  nature  and  relation- 
ships of  these  derivatives  have  become  more  and  more  numerous,  and  at 
present  the  greatest  activity  prevails  in  this  field  of  chemistry.  All  the 
evidence  accumulated  thus  far  is  in  harmony  with  the  view  that  many  of 
the  important  alkaloids  are  derivatives  of  pyridine,  in  the  same  sense  that 
the  so-called  aromatic  compounds  are  derivatives  of  benzene ;  and  as  the 
study  of  the  isomeric  derivatives  of  benzene  has  led  to  important  syntheti- 
cal results,  so  similar  work  in  the  pyridine  series  will  probably  lead  to  the 
synthesis  of  some  of  the  alkaloids. 
Byridine  Series,  CyH.;„-5N.— These  bases  were  discovered  by  Anderson 
in  bone  oil,  and  found  by  Thenius  to  be  present  in  coal  tar.  Cahours  and 
Etard,  in  1880,  succeeded  in  obtaining  them  from  nicotine  by  dry  distilla- 
tion. As  thirty  years  had  elapsed  since  the  time  of  Anderson's  work,  and 
these  bases  had  in  the  meantime  assumed  a  considerable  degree  of  import- 
ance, Richard,  and  Weidel,  and  Herzig  again  undertook  the  study  of  bone 
oil.  As  a  result  of  their  labors  we  now  know  that,  besides  pyridine,  there 
are  present  in  bone  oil  two  isomeric  picolines,  two  lutidines,  and  two  col- 
lidines.  Perkin,  in  1865,  first  observed  the  artificial  production  of  pyridine 
by  the  action  of  nascent  hydrogen  on  azodinaphthyldiamine,  and  since 
then  the  synthesis  of  this  base  has  been  frequently  attempted.  Methods 
have  been  described  by  Chapman  and  Smith,  by  Ramsay,  and  more 
recently  by  Konigs,  which  yield  small  quantities  of  joyridine,  but  for  its 
preparation  in  quantity  we  are  still  dependent  upon  bone  oil.  To  obtain 
pyridine  and  its  homologues,  bone  oil  is  warmed  w^ith  dilute  sulphuric 
acid,  the  filtered  solution  precipitated  with  sodium  hydroxide,  and  the  free 
bases  separated  by  fractional  distillation. ^    The  most  rapid  method  of 
1  Richard,  Bulletin  de  la  Societe  Chimique,  xxxii,  487. 
