546 
Constitution  of  the  Alkaloids. 
f  Am.  J  our.  Pharm. 
1      Nov.,  1883. 
possible  to  gradually  range  most  carbon  compounds  under  two  catego- 
ries, either  as  marsh-gas  or  as  benzol  derivatives,  as  fatty  compounds 
or  as  aromatic  compounds.  To  do  this,  methods  of  analysis  very 
different  from  those  used  in  mineral  chemistry  had  to  be  applied. 
The  mere  finding  out  of  percentage  composition  tells  us  little  or 
nothing  about  an  organic  compound.  What  the  elements  are  that 
compose  the  compound  is  not  to  be  found  out.  That  can  be  told 
beforehand  with  almost  absolute  certainty.  What  is  wanted  is  to  know 
how  the  atoms  of  carbon,  hydrogen,  oxygen,  and  nitrogen  are  linked 
together,  for,  strange  to  say,  these  differences  of  groupings,  which  may 
be  found  to  exist  between  these  three  or  four  elements,  endow  the 
compounds  with  radically  different  properties  and  serve  us  as  a  basis 
of  classification. 
The  development  of  this  part  of  chemistry,  therefore,  required  very 
different  methods  of  research.  Instead  of  at  once  destroying  a  com- 
pound in  order  to  learn  of  what  elements  it  was  composed,  we  submit 
it  to  a  course  of  treatment  with  reagents,  which  take  it  apart  very 
gradually,  or  modify  it  in  the  production  of  some  related  substance. 
In  this  way,  we  are  enabled  to  establish  its  relations  with  well-defined 
classes  and  to  put  it  in  its  proper  place.  Of  equal  importance  with 
the  analytical  method  of  study,  however,  is  the  synthetical.  This 
method  of  research,  as  applied  to  organic  compounds,  embodies  in  it 
the  highest  triumphs  of  modern  chemistry.  It  has  been  most  fruitful 
of  results,  both  theoretical  and  practical.  Within  recent  years,  hun- 
dreds of  the  products  of  vegetable  and  animal  life  have  been  built  up 
from  simpler  compounds.  Thousands  of  valuable  dye-colors  and 
other  compounds  used  in  the  arts  attest  its  practical  value.  It  may, 
therefore,  seem  anomalous  when  I  say  that  one  of  the  most  important 
of  all  the  classes  of  organic  compounds  has  not  shared  in  this  advance. 
The  alkaloids,  that  most  important  class  from  a  medical  and  pharma- 
ceutical point  of  view,  have  until  quite  recently  been  defined  in  the 
books  simply  as  "vegetable  bases,  containing  nitrogen."  Whether 
they  were  marsh-gas  or  benzol  derivatives  was  not  made  out;  how  the 
four  elements,  carbon,  hydrogen,  oxygen,  and  nitrogen,  were  grouped 
together  in  them  was  absolutely  a  thing  unknown.  Chemists  all 
admitted  two  things — first,  that  their  constitution  was  very  complex, 
and,  second,  that  the  synthesis  of  any  of  the  more  important  medici- 
nal alkaloids  would  be  an  eminently  desirable  thing  to  effect  from 
every  point  of  view.    Within  the  last  five  years,  however,  quite  con- 
