Am.  Jour.  Pharm.  \ 
Nov.,  1883.  ; 
Constitution  of  the  Alkaloids. 
547 
siderable  progress  has  been  made  in  arriving  at  a  clearer  understanding 
of  these  most  important  compounds,  and  I  shall  offer  to  your  attention 
this  evening  a  brief  statement  of  what  has  been  done  and  what  seems 
likely  to  be  accomplished  in  the  near  future. 
It  was  early  recognized  that  the  alkaloids  were  complex  amines  or 
ammonia  derivatives.  The  more  or  less  strongly  marked  basic  char- 
acter of  these  bodies,  the  presence  of  nitrogen  as  an  essential  element, 
and,  above  all,  the  analogy  shown  to  ammonia  in  the  way  these  bases 
united  with  acids  to  form  salts,  not  by  replacement  of  the  hydrogen 
of  the  acid,  but  by  direct  addition  of  acid  and  base,  pointed  unmistak- 
ably to  this  constitution.  But  with  this  granted,  the*  simplest  alkaloid 
formulas,  those  of  conine,  CgHj^N,  and  nicotine,  CioHj^Ng,  still  showed 
that  the  amine  molecule  contained  quite  complex  groups  of  carbon 
and  hydrogen  atoms,  and  the  great  majority  of  the  alkaloids — the 
non-volatile  ones — contained  groups  in  which  the  three  elements,  car- 
bon, hydrogen,  and  oxygen,  all  entered.  Hence  the  difficulty  in 
acquiring  a  knowledge  of  the  molecular  structure  of  those  alkaloids  at 
all  comparable  with  that  attained  in  the  case  of  other  organic  com- 
pounds. Of  course  synthesis  could  not  be  applied  until  analysis  had 
revealed  something  of  the  molecular  grouping  of  these  compounds,  so 
the  action  of  different  classes  of  reagents  was  tried  upon  the  alkaloids. 
Before  summarizing  the  results  of  this  study  of  the  decomposition 
and  alteration  products  of  the  alkaloids,  a  brief  reference  to  a  related 
class  of  organic  compounds  will  be  of  assistance  to  those  unfamiliar 
with  recent  researches  in  this  field. 
It  is  well  known  that  in  coal-tar  is  found  a  series  of  ammonia-like 
bases,  aniline  or  amido-benzol,  toluidine  or  amido-toluol,  and  xylidine 
or  amido-xylol,  which  are  utilized  practically  in  the  manufacture  of 
the  so-called  aniline  dye-colors.  It  is  perhaps  not  so  well  known  that 
there  are  other  series  of  bases  found  there  too.  The  first  of  these  is 
the  pyridine  series,  including  pyridine ,  C5H5N,  picoline  (methyl-pyri- 
dine)  C5H4N  (CH3),  lutidine  (dimethyl -pyridine)  C5H3N  (0113)2  and 
collidine  (trimethyl-pyridine)  O5H2N  (0113)3.  This  series  is  also 
found  in  relatively  larger  proportion  in  what  is  known  as  DippeFs  oil, 
the  product  of  the  dry  distillation  of  bones. 
The  second  series  is  the  quinoline  series,  including  quinoline  O9H7N, 
lepidine  (methyl-quinoline)  O^oHgN,  and  cryptidine  (dimethyl-quino- 
line)  O^HiiN.  The  two  compounds  which  give  name  to  these  series, 
pyridine,  C5H5N,  and  quinoline,  CgH^N,  respectively,  bear  to  each 
