548 
Constitution  of  the  Alkaloids. 
(  Am.  Jour.  Pharm, 
t      Nov.,  1883. 
other  a  relation  analogous  to  that  existing  between  benzol,  CgHg,  and 
naphthalene,  CioHg,  and  the  theory  generally  accepted  by  those  chem- 
ists who  have  been  occupying  themselves  with  these  bases  and  their  de- 
rivatives is  that  pyridine  is  simply  benzol,  in  which  an  atom  of  nitrogen 
replaces  the  triad  group  CH,  and  quinoline,  the  naphthalene  molecule 
with  a  similar  change.  Indeed,  Ladenburg  has  recently  succeeded  in 
obtaining  benzol  as  an  alteration  product  from  pyridine  in  certain  reac- 
tions. Moreover,  from  methyl-pyridine,  CgH^N  (CH3),  would  be 
derived  an  acid  known  as  pyridine-carboxylic  acid,  C5H4N  (COOH), 
just  as  benzoic  acid,  CgHgCOOH,  is  derived  from  methyl-benzol, 
C6H5CH3,  and  from  dimethyl-pyridine,  C5H3N  (0113)2,  an  acid  known 
as  pyridine-dicarboxylic  acid,  C5H3N  (C00H)2,  just  as  phthalic  acid, 
CgH^  (COOH)2,  is  derived  from  dimethyl-benzol,  CgH,  (CH3)2.  The 
same  thing  applies  to  quinoline  as  compared  to  naphthalene. 
We  may  now  look  at  the  question  of  the  decomposing  effect  of 
reagents  upon  the  alkaloids.  The  means  which  have  proved  most 
efficacious  in  decomposing  these  bases  are  the  action  of  oxidizing  and 
reducing  agents,  of  bromine,  of  organic  iodides,  of  concentrated  acids 
and  alkalies,  and  of  heat. 
Taking  up  the  volatile  alkaloids,  we  find  with  regard  to  Conine; 
first,  that  the  action  of  methyl  iodide  shows  it  to  be  a  secondary  amine, 
that  is,  it  retains  only  one  replaceable  hydrogen  atom  of  the  original  ammo- 
nia molecule.  Its  formula  is  therefore  CgHigNH.  From  conine  can 
be  prepared  methyl-conine,  which  also  occurs  in  nature  and  dimethyl- 
conine.  From  this  latter  has  been  gotten  a  hydrocarbon  C^^i^y  cony- 
lene,  homologous  with  acetylene  C2II2.  Conine,  on  oxydation,  yields 
chiefly  butyric  acid,  but  among  the  products  of  oxidation  has  been 
found  the  pyridine-carboxylic  acid  before  referred  to.  The  formula 
of  conine,  CgH^^N,  shows  it  to  be  homologous  with  piperidine  CgHuN, 
a  derivative  of  piperine,  the  alkaloid  of  pepper,  to  be  spoken  of  later, 
and,  just  as  piperidine  is  derived  from  pyridine  by  the  action  of 
reducing  agents,  so  conine  is  probably  derived  from  a  propyl-pyridine. 
The  artificial  alkaloid  paraconine  isomeric  with  the  natural  conine  will 
be  referred  to  later. 
Nicotine,  C^QH.^J^2y  ^^^^  simplest  in  formula  of  the  alkaloids,  is  a 
tertiary  base,  that  is,  contains  no  replaceable  hydrogen  atoms  in  its 
molecule.  It  shows  very  close  relations  to  pyridine.  When  nicotine 
va])or  is  passed  through  a  red-hot  tube,  it  yields  essentially  collidine, 
and  with  this,  some  pyridine,  picoline,  lutidine,  and  gases  such  as 
