Am.  Jour.  Pharm.  ( 
July,  1878.  J 
Quiniretin. 
351 
soon  as  it  is  neutralized  by  ammonia,  yet  quiniretin  is  not  dissolved  by 
an  excess  of  the  latter,  and  in  this  respect,  too,  it  differs  from  quinicia. 
It  must  be  granted  that  the  iodohydrargyrate  of  potassium  (1*35  per 
cent,  chloride  of  mercury,  5  iodide  of  potassium,  100  water)  yields  an 
abundant  precipitate  in  the  hydrochloric  solution  of  quiniretin,  but  the 
same  may  be  said  with  regard  to  other  salts,  for  instance  chloride  of 
ammonium  or  sodium. 
A  small  quantity  of  dilute  sulphuric  acid  (1*112  sp.  gr.)  gently 
warmed  and  shaken  for  a  day  or  two  with  a  large  excess  of  quiniretin, 
affords  always  an  acid  liquid  of  a  yellowish  hue,  far  less  colored  than 
the  hydrochloric  solution.  The  former  is  not  fluorescent,  and  is 
decolorized  by  chlorine  water.  On  addition  of  ammonia  the  latter 
assumes  a  dingy  green  hue  or  yields  a  greenish  precipitate  ;  these  reac- 
tions succeed  better  if  quiniretin  is  immediately  dissolved  in  chlorine 
water  (it  will  usually  contain  an  appropriate  amount  of  hydrochloric 
acid)  and  ammonia  added  to  it.  This  behavior  agrees  with  that  of 
quinia,  quinicia  and  quinidia  (conquinia),  yet  quiniretin  again  differs 
from  these  three  alkaloids,  inasmuch  as  it  does  not  afford  that  red  tar 
(Grahe's  test)  which  makes  its  appearance  if  barks  containing  quinia 
or  the  allied  alkaloids,  or  certain  salts  of  them,  are  heated  in  a  glass 
tube. 
Quiniretin,  consequently,  differs  very  widely  in  many  respects  from 
quinia,  its  mother  substance,  the  composition  of  which  quiniretin  must 
necessarily  share  with  regard  to  the  conditions  of  its  formation,  as 
pointed  out  above.  I  may  add  that  I  have  restricted  myself  to  ascer- 
taining the  presence  of  nitrogen  as  a  constituent  of  quiniretin.  The 
intense  action  of  sunlight,  especially  in  summer,  causes  the  quinia  to 
be  transformed.  The  alteration  is  not  precisely  more  favored  by  acids  ; 
the  aqueous  and  also  the  alcoholic  solution  of  pure  quinia  is  more 
rapidly  transformed  ;  dry  quinia  requires  more  time.  The  other  alka- 
loids of  cinchona  are  much  less  affected  by  sunlight  than  quinia,  at  least 
in  aqueous  solution.  This,  no  doubt,  depends  upon  their  sparing  solu- 
bility, quinia  being  more  readily  dissolved  by  water.  It  is  interesting 
to  see  how  little  kinic  acid  is  altered  by  sunlight ;  saturated  or  diluted 
aqueous  solution  of  it  was  but  almost  imperceptibly  affected  after  a 
summer's  stay  in  sunshine.  As  to  quinovin,  I  noticed  the  absolute 
absence  of  any  coloration  after  a  similar  treatment. 
Aqueous  solution  of  morphia  is  very  slightly  colored  by  sunlight, 
