550  Constitution  of  the  Alkaloids.  { ^^Norissa"'"' 
CgHgNOg,  and  finally  cinchomeronic  acid,  C7H5NO4.  Now  the  two 
acids  last  mentioned  are  simple  substitution  products  of  pyridine, 
oxycinchomeronic  acid  being  a  pyridine-tricarboxylic  acid  C5H2N 
(COOH)3,  and  cinchomeronic  acid,  a  pyridine-dicarboxylic  acid^ 
€5113^(00011)2.  When  distilled  with  potassium  hydrate,  quinine 
yields  quinoline  and  its  homologues.  The  alkaloid  has  been  shown  to 
be  a  tertiary  base. 
Quinidine  yields  with  chromic  acid  the  same  decomposition  products 
as  quinine. 
Cinchonine,  CJ9H22N2O,  the  second  most  important  alkaloid  of  these 
barks,  when  oxidised  with  potassium  permanganate,  yields  cinchonic 
acid,  which  is  a  quinoline-carboxylic  acid  C9HgN(C00H),  cincho- 
meronic acid,  which  has  just  been  stated  to  be  a  pyridine-dicarboxylic 
acid,  and  a  pyridine-tricarboxylic  acid.  When  cinchonine  is  treated 
with  potassium  hydrate,  it  is  decomposed  into  quinoline  and  a  solid 
body,  which  on  further  treatment  yields  a  liquid  base  C7H9N,  which  is 
probably  lutidine.  It  has  been  found,  moreover,  that  both  tetrahydro- 
quinoline  and  dihydroquinoline,  hydrogen  addition  products  of  quino- 
line, are  present.  When  cinchonine  is  distilled  with  solid  potassium 
hydrate,  it  yields  pyrrol  and  bases  of  both  the  pyridine  and  quinoline 
series. 
Clnchonidine,  when  heated  with  potassium  hydrate,  yields  quinoline 
also,  and  with  nitric  acid  the  same  products  as  cinchonine. 
Strychnine  has  been  found  to  be  a  tertiary  amine.  When  distilled 
with  potassium  hydrate,  quinoline  is  formed. 
Brucine  is  a  tertiary  diamine,  that  is,  formed  by  substitution  in  a 
double  ammonia  molecule.  When  distilled  with  potassium  hydrate  it 
yields  quinoline,  lutidine,  and  two  isomeric  collidines. 
The  alkaloid  Atropine  has  been  quite  thoroughly  studied  with  results 
of  great  interest.  When  heated  with  either  baryta-water  or  hydro- 
chloric acid,  it  takes  up  a  molecule  of  water  and  is  split  into  tropine,, 
CgHigNO,  and  tropic  acid,  CgHjoOg.  This  latter  is  phenyl-oxypropionic 
acid.  Tropine,  when  heated  to  180°.C,  with  concentrated  hydro- 
chloric acid,  splits  off  a  molecule  of  water,  Itnd  yields  tropidine, 
C8H13N,  a  liquid  base,  with  an  odor  resembling  conine.  When  this 
tropidine  is  heated  with  an  excess  of  bromine,  it  yields  dibrompyri- 
dine. 
Piperine,  the  alkaloid  of  pepper,  has  also  been  well-studied.  When 
boiled  with  alcoholic  potash  solution,  it  takes  up  a  molecule  of  water 
