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PREPARATION  OP  CRYSTALLIZED   PHENIC  ACID.     P  ,125  '9^R 
great  analogy  with  the  chloride  and  the  other  compounds  of  tWs'/^  3FF\Ck 
family,  differs  essentially  from  the  soluble  fluoride  of  silver  of 
chemists,  which,  according  to  M.  Prat,  is  a  compound  of — 
AgFl,  AgO,  HO,  in  the  hydrated  state ; 
AgFl,  AgO,  in  the  anhydrous  state. 
Fluorine  combines  with  chlorine.    To  obtain  this  compound  it 
is  sufficient  to  pour  a  weak  solution  of  the  hydrofluoric  acid  of 
the  chemists  into  a  solution  of  hypochlorous  acid :  there  form 
F1H,  HO  +  CIO  =  2HO  +  F1C1. 
Fluoride  of  chlorine  is  gaseous,  of  a  more  intense  color  than 
chlorine.    It  converts  silver  into  a  mixture  of  chloride  and  fluo- 
ride. 
Fluorine  may  be  isolated,  according  to  M.  Prat,  by  heating 
fluoride  of  lead  of  chemists  (1  part)  either  with  nitre  (5  parts)  or 
with  binoxide  of  manganese  (2  parts) ;  oxygen  and  fluorine  are 
evolved.  A  platinum  alembic  must  be  used.  The  oxygen  is 
removed  from  the  mixture  by  passing  over  fragments  of  heated 
baryta. 
Fluorine  is  gaseous,  almost  colorless,  of  a  chlorous  odor,  visi- 
bly fuming  in  the  air,  incombustible,  and  heavier  than  air.  It 
bleaches  indigo,  and  reddens  and  bleaches  litmus.  Ammonia 
produces  fumes  with  fluorine,  and  will  thus  detect  traces  of  it. 
It  immediately  decomposes  water  at  the  ordinary  temperature. 
It  combines  with  hydrogen  in  diffused  light.  Fluorine  decom- 
poses hydrochloric  acid  gas,  and  eliminates  bromine  and  iodine 
from  their  compounds.  It  unites  with  boron  and  silicium,  and 
with  all  metals  of  the  first  five  groups. — Loud.  Chem.  JVews,  Jan, 
10,  1868. 
NOTE  ON  THE  PREPARATION  OF  CRYSTALLIZED  PHE- 
NIO  ACID. 
By  W.  E.  Bickerdike,  F.C.S. 
It  is  seldom  that  crystallized  phenic  acid  can  be  obtained  by 
the  common  process  described  for  its  preparation  in  the  text- 
books ;  and  even  when  the  crude  liquid  does  crystallize,  the  still 
fluid  portion  contains  the  largest  amount  of  the  pure  acid. 
The  following  process  I  find  always  to  give  good  results : 
