316 
ON  THE  NITRATES  OF  IRON. 
small  quantities  of  the  elements  are  dissolved  by  the  fatty  acids, 
but  no  hydrochloric  or  hydrobromic  acids  are  produced.  Oleic 
acid,  on  the  contrary,  is  readily  acted  upon,  and  furnishes  the 
following  compounds : — 
Chlorinated  Oleic  Acid. — It  is  liquid  at  ordinary  temperatures, 
heavier  than  water,  and  possesses  a  very  strong  brown  color ;  it 
produces  no  precipitate  with  nitrate  of  silver.  Its  consistence 
is  a  little  greater  than  that  of  the  pure  acid  ;  its  specific  gravity, 
at  a  temperature  of  46°  F.,  is  1-082  ;  it  boils  at  374°  F.  Its 
formula  is  C3S  H32  CI2  O4. 
Brominated  Oleic  Acid. — This  possesses  about  the  same  con- 
sistence as  the  preceding  ;  its  color  is  a  darker  brown,  although 
reagents  give  no  sign  of  the  presence  of  free  bromine  when  it 
has  been  well  washed  and  not  kept  too  long.  Its  specific  gravity 
at  a  temperature  of  45°-5  F.,  is  1-282  ;  it  boils  at  392°  F.  Its 
analysis  gave  numbers  agreeing  with  the  formula  C36  H32Br2  O4. 
The  author  considers  that  stearine  and  margarine  belong  to 
the  class  of  isomeric  compounds,  and  that  the  vegetable  fatty 
oils  are  compounds  in  definite  proportions  of  oleine  and  marga- 
rine, or  perhaps  rather  oleo  margarates  of  glycerine,  the  resolu- 
tion of  which  may  be  affected  by  the  most  feeble  agents. — Lon- 
don Chem.  Gaz.,  from  the  Qomptus  Bendus,  xxxvii.,  p.  28. 
ON  THE  NITRATES  OF  IKON. 
By  S.  Hausmann. 
The  author  has  carefully  investigated  Schonbein's  nitrate  of 
iron  in  Fresenius's  laboratory.  The  acid  nitrate  of  iron  was 
prepared  by  evaporating  the  reddish-brown  solution  of  iron  in 
nitric  acid  to  the  consistence  of  a  syrup,  and  then  adding  half 
its  volume  in  nitric  acid.    The  crystals  which  form  are — 
Neutral  Nitrate  of  Iron,  Fe2  O3,  3N05+12HO.— Prismatic 
crystals,  fusing  at  95°  F.  Ordway  (Chem.  Gaz.,  vol.  viii.  p.  61) 
gave  the  formula  Fe2  O3,  3N05+18HO  for  it.    Analysis  :— 
Fe2  O3 
.  21-47 
1 
=  80 
22-85 
NO5  . 
.  46-78 
3 
162 
46-29 
HO  . 
.  31.75 
12 
108 
30-86 
When  the  very  concentrated  solution  of  nitrate  of  iron  is 
mixed  with  as  much  water  as  will  reduce  its  dark  red  color  to  a 
