372 
Paricine  and  Aricine. 
J  Am.  Jour  Pharra, 
t      July,  *%79<- 
PARICINE  AND  ARICINE. 
By  Dr.  O.  Hesse. 
In  reference  to  the  recent  letter  from  Mr.  J.  E.  Howard  upon  the 
cinchona  alkaloids,  I  desire  to  make  the  following  detailed  com- 
munication upon  paricine,  with  the  remark  that  an  abstract  of  it  has 
already  been  published  in  1877,  in  the  "  Berichte  der  deutschen  chem- 
ischen  Gesellschaft,"  vol.  x.,  p.  2160. 
In  obtaining  of  paricine  in  1873'  ^  commenced  with  its  nitrate, 
which,  as  is  known,  is  precipitated  by  nitric  acid  from  the  sulphuric 
acid  solution  of  the  cinchona  alkaloids  yielded  by  C.  succirubrai.  But 
the  preparation  of  the  pure  alkaloid  from  the  nitrate  presents  great 
difficulty,  owing  to  the  facility  with  which  it  oxidizes.  On  this  account 
I  have  abandoned  this  method  of  preparing  the  alkaloid  in  favor  of  one- 
based  upon  another  of  its  properties,  namely,  that  paricine  does  not 
neutralize  sulphuric  acid.  If,  therefore,  a  moderately-dilute  solution  of 
the  entire  alkaloids  of  C.  succirubra  in  sulphuric  acid  be  so  far  neutral- 
ized with  a  concentrated  aqueous  solution  of  sodium  carbonate  that  red 
litmus  paper  is  only  just  turned  blue  by  it,  the  paricine  is  almost  entirely 
precipitated.  In  order  to  free  the  paricine  from  the  last  traces  of  the 
other  alkaloids  which  adhere  to  the  amorphous  precipitate,  it  is  digested 
at  a  gentle  heat  with  excess  of  dilute  sulphuric  acid,  when  the  paricine 
is  left  almost  undissolved  in  the  form  of  sulphate  as  a  yellow  mass. 
After  the  cooling  of  the  solution  this  is  collected  and  digested  with 
soda  solution,  and  then  the  alkaloid  is  taken  up  with  the  smallest  possi- 
ble quantity  of  ether,  in  which  it  is  very  readily  soluble. 
The  ethereal  solution  is  dark  reddish-brown  colored,  and  to  k  is 
added  small  quantities  of  pure  light  petroleum  spirit,  which  causes  the 
formation  of  a  dark-brown  flocculent  precipitate  that  eventually  aggre- 
gates to  a  black-brown  resinous  layer  covering  the  bottom  of  the  vessel. 
The  addition  of  the  petroleum  spirit  is  continued  until  the  solution  has 
only  a  light-yellow  color.  After  this  solution  has  become  clear,  it  is 
poured,  drop  by  drop,  into  a  larger  quantity  of  light  petroleum  spirit, 
when  a  yellowish-white  flocculent  precipitate  is  formed,  which  is 
removed  by  filtration  and  washed  with  pure  light  petroleum  spirit. 
This  mass  is  next  spread  out  in  the  air,  in  order  to  free  it  from 
adhering  petroleum  spirit,  then  again  dissolved  in  a  little  ether  and  the 
1  Liebig's  "  Annalen,"  vol.  clxvi,  p.  263. 
