372 
Cod  Liver  Oil. 
Am.  Jour.  Pharrn. 
July,  1890. 
resin  that  rises  to  the  top  of  the  water,  in  which  it  dissolves  partially 
when  heated.  To  purify  this  acid  it  is  dissolved  in  dilute  potash 
solution,  the  liquor  neutralized  with  nitric  acid  and  acetate  of  lead 
carefully  added.  The  first  brown  precipitates  that  form  are  sepa- 
rated and  rejected,  and  there  is  obtained  afterwards  a  grayish-white 
plumbic  precipitate,  from  which  can  be  separated  by  treatment  with 
sulphuretted  hydrogen,  a  dirty  yellow  body  that  crystallizes  in 
prisms  or  in  square  plates  bristling  with  points.  The  formula  attri- 
buted to  this  acid,  as  the  result  of  analysis,  differs  from  that  of 
tyrosine  (C7HnN03)  only  in  containing  two  atoms  of  hydrogen  more. 
Morrhuic  acid  is  a  weak  acid,  which  reddens  litmus,  decomposes 
carbonates,  is  easily  soluble  in  alkalies,  with  which  it  forms  salts 
that  precipitate  the  acetates  of  lead  and  nitrate  of  silver,  but  not 
acetate  of  copper.  It  is  slightly  soluble  in  hot  water  and  separates 
from  it  partially  on  cooling  in  the  form  of  an  emulsion.  The  solu- 
tions have  a  slightly  bitter  disagreeable  taste  ;  their  aromatic  odor 
sometimes  recalls  that  of  cod  liver  oil  and  sometimes  that  of  sea- 
weed. Upon  very  slow  evaporation  of  a  dilute  alcoholic  solution  the 
acid  crystallizes  in  prisms  having  a  square  base,  or  in  large  plates, 
but  a  considerable  proportion  remains  a  long  time  in  the  form  of 
oleaginous  drops.  Morrhuic  acid  belongs  to  the  pyridic  series  of 
compounds,  though  it  cannot  be  properly  called  a  carbopyridic  acid 
for  it  is  not  precipitated  with  heat  by  acetate  of  copper,  but  a  pyridic 
acid  having  a  constitution  recalling  that  represented  by  phenyllactic 
acid  (C6H5 — CHOH — C02H)  or  cinnamic  acid  in  the  benzene  series. 
It  behaves  both  as  a  moderately  energetic  acid  and  as  a  weak  base. 
The  substance  described  by  De  Jongh  under  the  name  "  gaduine  '* 
appears  to  correspond  with  morrhuic  acid.  This  substance,  which 
is  perfectly  harmless,  possesses  most  powerful  diuretic  properties, 
quite  similar  to  those  the  authors  have  recognized  in  morrhuine. 
Under  the  influence  of  morrhuic  acid,  the  urine  of  guinea  pigs, 
usually  scanty  and  turbid,  augments  considerably  in  quantity  and 
rapidly  becomes  clear,  at  the  same  time  the  animals  attack  food  with 
avidity.  These  characters  show,  in  the  authors'  opinion,  that  mor- 
rhuic acid,  like  morrhuine,  excites  the  assimilatory  functions  and  the 
appetite.  The  bases  properly  so-called  exist  in  cod  liver  oil  in  small 
quantity,  but  morrhuic  acid  occurs  in  it  to  the  extent  of  upwards  of 
a  gram  per  litre.  It  would  appear  therefore  to  be  one  of  the  most 
important  agents  in  the  efficacy  of  the  oil. 
