5  I  o  Aromatic  Products  of  the  Animal  Body,  f^""- JcZisso^'"'' 
to  very  little  (though  sufficient  for  the  color)  if  the  preparation  has  been 
gone  through  with  due  care.    Analysis  will  sufficiently  show  this. 
The  oxydizable  properties  of  the  mixture  will  become  evident  if  a 
drop  is  exposed  to  the  air  on  the  lid  of  a  cup.  At  once  the  color  will 
change,  while  at  last  the  liquid  will  have  a  color  little  darker  than  the 
original  oil.  If  the  drop  is  made  to  spread  by  strongly  blowing  upon 
it,  the  above  reaction  will  appear  much  more  quickly,  on  account  of 
the  higher  temperature  as  well  as  the  vapor  of  water  of  the  breath. 
It  is  very  remarkable  that  water  will  spoil  the  mixture.  We  once 
had  to  ascribe  the  loss  of  about  lo  tuns  to  this  cause.  This  influence 
of  water  may  be  easily  shown.  If  i  drop  of  water  is  shaken  up  with 
about  10  grams  of  the  oil  in  a  well-corked  bottle,  great  changes  will 
soon  be  observed  in  the  color.  The  water  seems  to  rob  the  oil  of  the 
ferro  iodide  for  some  part,  and  for  the  other  to  decompose  it  by  mutual 
influence. 
It  is  still  noteworthy  that  the  quantity  of  iron  was  larger  than  was 
absolutely  necessary,  because  this  quickens  the  combination.  Exact 
investigations,  made  expressly  for  this  purpose,  have  clearly  shown  that 
the  codliver  oil  which  is  prepared  with  the  due  observances  remains 
constant. — Pharm.  Journ.  and  Trans. ^  Sept.  ii,  1880 
AROMATIC  PRODUCTS  OF  THE  ANIMAL  BODY. 
By  E.  Baumann, 
Hydroparacoumaric  acid  being  the  first,  and  under  the  conditions 
given  by  the  author,  the  final  putrefaction  product  of  tyrosin,  putre- 
fection  afi-ords  a  convenient  method  of  preparing  it.  20  grams  of 
tyrosin  thus  yield  12  grams  of  hydroparacoumaric  acid.  Salkowski 
has  shown  that  when  it  occurs  amongst  the  decomposition-products 
of  albumin,  it  is  also  derived  from  previously-formed  tyrosin. 
The  homologous  parahydroxyphenylacetic  acid  is  also  generated  dur- 
ing the  digestion  of  albumin,  and  may  be  detected  in  the  unne  by 
evaporating  5  to  10  cc.  with  hydrochloric  acid  to  remove  phenols,  and 
extracting  with  ether.  With  iVI ikon's  reagent  the  ethereal  extract 
gives  the  red  color  characteristic  of  hydroxy  acids.  The  acid  may  be 
prepared  by  evaporating  25  liters  of  urine  to  ij  liters,  strongly  acidify- 
ing with  acetic  acid  and  shaking  with  ether,  a  little  alcohol  being  added 
to  decompose  the  emulsion  which  frequently  forms.  The  extract, 
freed  from  acetic  acid,  is  again  dissolved  in  water  and  exhausted  with 
